zoukankan html css js c++ java

27 自定义View 和案例

有时安卓提供的View不满足我们的需求时可以创建一个类继承View或其子类重写方法

package com.qf.sxy.day28_customview.view;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.View;

/**
 * Created by sxy on 2016/9/28.
 */
public class MyTextView extends View {
    /**
     * 在逻辑代码中使用
     * @param context
     */
    public MyTextView(Context context) {
        super(context);
    }

    /**
     * 布局文件中使用    note:布局中使用必须有俩个参数
     * @param context
     * @param attrs   布局中设置的属性
     */
    public MyTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    /**
     * @param context
     * @param attrs 布局中设置的属性
     * @param defStyleAttr 指定样式资源
     */
    public MyTextView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }


    /**
     * 绘制的方法
     * @param canvas   画布
     */
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        //创建画笔对象
        Paint paint =  new Paint();
        paint.setColor(Color.BLUE);
//        paint.setColor(0xff00);//0x 红  绿 蓝
        paint.setStrokeWidth(3);//设置画笔粗细
        paint.setAntiAlias(true);//抗锯齿 边缘柔和
        paint.setTextSize(30);//设置文字大小
        paint.setStyle(Paint.Style.STROKE);//设置样式  空心
        /**
         * 画直线
         * 参数1:x轴起始位置
         * 参数2:y轴起始位置
         * 参数3:x轴终止位置
         * 参数4:y轴终止位置
         * 参数5:画笔对象
         */
        canvas.drawLine(0,0,getWidth(),getHeight(),paint);

        /**
         * 画圆
         * 参数1,2:圆心
         * 参数3:半径
         * 参数4:画笔
         */
        canvas.drawCircle(200,200,100,paint);

        /**
         * 画文字
         * 参数1:内容
         * 参数2,3:起始位置
         * 参数4:画笔
         */
        canvas.drawText("国庆快乐",0,100,paint);

        /**
         * 画图片
         */
       // canvas.drawBitmap();
        /**
         * 画矩阵
         */
       // canvas.clipRect()

        //....
    }
}

在使用此自定义View的时候在布局文件写完整的包名类名

如

  <!--
    使用自定义View   包名+类名
    -->
    <com.qf.sxy.day28_customview.view.MyTextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        />

如果我们想在布局文件中设置属性的话那么可以按一下步骤

在valus文件夹新建一个resources文件

如

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <!--
    circleColor  圆的颜色
    sweepColor   扫描的颜色
    startAngle 起始角度
    sweepAngle 扫描角度
    sweepStep 每次扫描的步数
    -->
    <declare-styleable name="ProgressView">
        <attr name="circleColor" format="color|reference"></attr>
        <attr name="sweepColor" format="color|reference"></attr>
        <attr name="startAngle" format="integer|reference"></attr>
        <attr name="sweepAngle" format="integer|reference"></attr>
        <attr name="sweepStep" format="integer|reference"></attr>
    </declare-styleable>
</resources>

赋值方法

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical"
    tools:context="com.qf.sxy.customview3.MainActivity">

    <com.qf.sxy.customview3.widget.ProgressView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:circleColor="#00ff00"
        app:sweepColor="#0000ff"
        app:sweepStep="10"
        app:sweepAngle="0"
        app:startAngle="0"
         />
    <com.qf.sxy.customview3.widget.ProgressView
        android:layout_width="200dp"
        android:layout_height="200dp"
        app:circleColor="#0000ff"
        app:sweepColor="#ff00ff"
        app:sweepStep="2"
        app:startAngle="-90"
         />
    <com.qf.sxy.customview3.widget.ProgressView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:circleColor="#00ffff"
        app:sweepColor="#005644"
        app:sweepStep="20"
        app:startAngle="180"
         />
</LinearLayout>

获取属性值

  public ProgressView(Context context) {
                this(context,null);
            }

            public ProgressView(Context context, AttributeSet attrs) {
                super(context, attrs);
                //获取布局中属性
                TypedArray array = context.obtainStyledAttributes(attrs,R.styleable.ProgressView);
                if(array!=null){
                    circleColor = array.getColor(R.styleable.ProgressView_circleColor,Color.BLUE);
                    sweepColor = array.getColor(R.styleable.ProgressView_sweepColor,Color.RED);
                    startAngle = array.getInteger(R.styleable.ProgressView_startAngle,-90);
                    sweepStep = array.getInteger(R.styleable.ProgressView_sweepStep,1);
                }

            }

具体案例一

一个最基础的案例继承一个View画一个圆等

重写View文件MyTextView.java

package com.qf.sxy.day28_customview.view;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.View;

/**
 * Created by sxy on 2016/9/28.
 */
public class MyTextView extends View {
    /**
     * 在逻辑代码中使用
     * @param context
     */
    public MyTextView(Context context) {
        super(context);
    }

    /**
     * 布局文件中使用    note:布局中使用必须有俩个参数
     * @param context
     * @param attrs   布局中设置的属性
     */
    public MyTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    /**
     * @param context
     * @param attrs 布局中设置的属性
     * @param defStyleAttr 指定样式资源
     */
    public MyTextView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }


    /**
     * 绘制的方法
     * @param canvas   画布
     */
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        //创建画笔对象
        Paint paint =  new Paint();
        paint.setColor(Color.BLUE);
//        paint.setColor(0xff00);//0x 红  绿 蓝
        paint.setStrokeWidth(3);//设置画笔粗细
        paint.setAntiAlias(true);//抗锯齿 边缘柔和
        paint.setTextSize(30);//设置文字大小
        paint.setStyle(Paint.Style.STROKE);//设置样式  空心
        /**
         * 画直线
         * 参数1:x轴起始位置
         * 参数2:y轴起始位置
         * 参数3:x轴终止位置
         * 参数4:y轴终止位置
         * 参数5:画笔对象
         */
        canvas.drawLine(0,0,getWidth(),getHeight(),paint);

        /**
         * 画圆
         * 参数1,2:圆心
         * 参数3:半径
         * 参数4:画笔
         */
        canvas.drawCircle(200,200,100,paint);

        /**
         * 画文字
         * 参数1:内容
         * 参数2,3:起始位置
         * 参数4:画笔
         */
        canvas.drawText("国庆快乐",0,100,paint);

        /**
         * 画图片
         */
       // canvas.drawBitmap();
        /**
         * 画矩阵
         */
       // canvas.clipRect()

        //....
    }
}

布局文件activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.qf.sxy.day28_customview.MainActivity">

<!--
使用自定义View   包名+类名
-->
<com.qf.sxy.day28_customview.view.MyTextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    />
</RelativeLayout>

具体案例二

说明
展示如何设置属性然后在布局文件里面赋值和在重写类获取对应属性值

这里写图片描述

(重写View方法的类)MyTextView.java

package com.qf.sxy.customview02.widget;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.View;
import android.widget.TextView;

import com.qf.sxy.customview02.R;

/**
 * Created by sxy on 2016/9/28.
 */
public class MyTextView extends View {

    TextView tv;

    private Paint mPaint;

    private String mText="哈哈";
    public MyTextView(Context context) {
        super(context);
        initPain();
    }

    public MyTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        initPain();

        //获取布局资源中的属性
        TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.MyTextView);

        //获取文本内容
        CharSequence ch = array.getText(R.styleable.MyTextView_text);
        if(ch!=null&&!"".equals(ch)){
            setText(ch.toString());
        }
        //获取文本颜色
        int textColor = array.getColor(R.styleable.MyTextView_textColor,Color.BLACK);
        settextColor(textColor);

        //获取字体大小
        int textSize = (int)(array.getDimension(R.styleable.MyTextView_textSize,30));
        setTextSize(textSize);


    }


    //设置字体大小
    private void setTextSize(int textSize) {
        mPaint.setTextSize(textSize);
        requestLayout();//重新绘制画布 会
        invalidate();//进行刷新(重新获取数据)
    }


    //设置文本颜色
    public void settextColor(int textColor) {
        mPaint.setColor(textColor);
        requestLayout();//重新绘制画布
        invalidate();//进行刷新(重新获取数据)
    }
    //给文本设置内容
    private void setText(String str) {
        mText = str;
        //onMeasure只会重新调用次方
        requestLayout();//重新绘制画布
        //重新调用ondraw方法 和上诉方法正好相反
        invalidate();//进行刷新(重新获取数据)
    }

    public MyTextView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        initPain();
    }


    //初始化画笔对象
    public void initPain() {
        mPaint = new Paint();
        mPaint.setColor(Color.RED);
        mPaint.setAntiAlias(true);
        mPaint.setTextSize(30);
        //设置文字的内边距
        setPadding(10,10,10,10);
    }


    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        //给画布设置颜色
        canvas.drawColor(Color.GREEN);

        canvas.drawText(mText,getPaddingLeft(),getPaddingTop()-mPaint.ascent(),mPaint);
    }

    /**
     * 测量控件大小
     * @param widthMeasureSpec
     * @param heightMeasureSpec
     */
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

//        //得到设置的模式
//        int wMode = MeasureSpec.getMode(widthMeasureSpec);
//        //获取父布局的宽高/50dp
//        int wSize = MeasureSpec.getSize(widthMeasureSpec);
//
//        /**
//         * MeasureSpec.UNSPECIFIED:Adapter View用到  未设定尺寸
//         * MeasureSpec.AT_MOST:wrap_content  根据里面内容变化而变化
//         * MeasureSpec.EXACTLY:match_parent/50dp   精准的值
//         */
//
//        if(wMode == MeasureSpec.AT_MOST){//wrap_content  根据里面内容变化而变化
//            //获取宽  计算
//
//        }else if(wMode == MeasureSpec.EXACTLY){ //match_parent/50dp   精准的值
//            //wSize
//        }

        //设定最终的宽和高
       setMeasuredDimension(Measure(widthMeasureSpec,1),Measure(heightMeasureSpec,2));
    }


    //进行测量
    public int Measure(int Spec ,int type){

        int result=0;//返回的值

        int mode = MeasureSpec.getMode(Spec);
        int size = MeasureSpec.getSize(Spec);

        if(mode == MeasureSpec.AT_MOST){//wrap_content  根据里面内容变化而变化
            //计算
            if(type==1){//获取宽     左右内边距+文字宽
                result = (int)(getPaddingLeft()+getPaddingRight()+mPaint.measureText(mText));
            }else if(type==2){//获取高
                result = (int)(getPaddingTop()+getPaddingBottom()+mPaint.descent()-mPaint.ascent());
            }

        }else if(mode == MeasureSpec.EXACTLY){ //match_parent/50dp   精准的值
            //wSize
            result = size;
        }

        return result;
    }



}

设置属性文件attrs.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <!--
      <declare-styleable name="样式名称">
      name ="名称" format="类型"
      string  字符串
      reference  引用的类型  R.string.xxx
      dimension 尺寸
      color 颜色
        <attr name="text" format="string|reference"></attr>
    </declare-styleable>

    -->
    <declare-styleable name="MyTextView">
        <attr name="text" format="string|reference"></attr>
        <!--dimension可以在此属性写 XXXDP或者XXXDIP-->
        <attr name="textSize" format="dimension|reference"></attr>
        <attr name="textColor" format="color|reference"></attr>
    </declare-styleable>
</resources>

activity_main.xml布局文件

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.qf.sxy.customview02.MainActivity">

    <!--
    命名空间  引用资源的
     xmlns:app="http://schemas.android.com/apk/res-auto"

      xmlns:app="http://schemas.android.com/apk/包名"
    -->

    <com.qf.sxy.customview02.widget.MyTextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:text="国庆快乐"
        app:textSize="20sp"
        app:textColor="#ff00ff"
       />
</RelativeLayout>

案例三

说明在界面画一个圆然后让其一直旋转 360APP的雷达效果

这里写图片描述

ProgressView.java(重写View方法)

package com.qf.sxy.customview3.widget;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.view.View;

import com.qf.sxy.customview3.R;

/**
 * Created by sxy on 2016/9/28.
 */
public class ProgressView extends View {

    private int circleColor = Color.BLUE;//设置颜色

    private int startAngle = -90;//开始的角度
    private int sweepAngle = 0;//扫描的角度
    private int sweepStep = 5;//每次扫描走多少
    private int sweepColor = Color.RED;

    //wrap_content  设定宽高  100
    int sweepWith =100;
    int sweepHeight =100;

    public ProgressView(Context context) {
        this(context,null);
    }

    public ProgressView(Context context, AttributeSet attrs) {
        super(context, attrs);
        //获取布局中属性
        TypedArray array = context.obtainStyledAttributes(attrs,R.styleable.ProgressView);
        if(array!=null){
            circleColor = array.getColor(R.styleable.ProgressView_circleColor,Color.BLUE);
            sweepColor = array.getColor(R.styleable.ProgressView_sweepColor,Color.RED);
            startAngle = array.getInteger(R.styleable.ProgressView_startAngle,-90);
            sweepStep = array.getInteger(R.styleable.ProgressView_sweepStep,1);
        }

    }


    /**
     * 绘制
     * @param canvas
     */
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        Paint paint = new Paint();
        paint.setColor(circleColor);
        paint.setAntiAlias(true);

        //绘制圆  控件的一半
        canvas.drawCircle(getWidth()/2,getHeight()/2,getWidth()/2,paint);

        //重新设置画笔颜色
        paint.setColor(sweepColor);
        //绘制的扇形
        canvas.drawArc(new RectF(0,0,getWidth(),getHeight()),startAngle,sweepAngle,true,paint);
        sweepAngle += sweepStep;//扫描角度等于 走的和
        sweepAngle= sweepAngle>360?0:sweepAngle;//是否跑了一圈
        invalidate();//刷新数据
    }

    /**
     * 测量
     * @param widthMeasureSpec
     * @param heightMeasureSpec
     */
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);


        int wMode = MeasureSpec.getMode(widthMeasureSpec);
        int hMode = MeasureSpec.getMode(heightMeasureSpec);

        int wSize = MeasureSpec.getSize(widthMeasureSpec);
        int hSize = MeasureSpec.getSize(heightMeasureSpec);


        switch (wMode){
            case MeasureSpec.AT_MOST:
               // wSize = sweepWith;
                wSize = hSize = sweepHeight;

                break;
            case MeasureSpec.EXACTLY:
                wSize = hSize = Math.min(wSize,hSize);
                break;
        }
        //设置最终的宽高
        setMeasuredDimension(wSize,hSize);

    }
}

属性文件attrs.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <!--
    circleColor  圆的颜色
    sweepColor   扫描的颜色
    startAngle 起始角度
    sweepAngle 扫描角度
    sweepStep 每次扫描的步数
    -->
    <declare-styleable name="ProgressView">
        <attr name="circleColor" format="color|reference"></attr>
        <attr name="sweepColor" format="color|reference"></attr>
        <attr name="startAngle" format="integer|reference"></attr>
        <attr name="sweepAngle" format="integer|reference"></attr>
        <attr name="sweepStep" format="integer|reference"></attr>
    </declare-styleable>
</resources>

布局文件activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical"
    tools:context="com.qf.sxy.customview3.MainActivity">

    <com.qf.sxy.customview3.widget.ProgressView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:circleColor="#00ff00"
        app:sweepColor="#0000ff"
        app:sweepStep="10"
        app:sweepAngle="0"
        app:startAngle="0"
         />
    <com.qf.sxy.customview3.widget.ProgressView
        android:layout_width="200dp"
        android:layout_height="200dp"
        app:circleColor="#0000ff"
        app:sweepColor="#ff00ff"
        app:sweepStep="2"
        app:startAngle="-90"
         />
    <com.qf.sxy.customview3.widget.ProgressView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:circleColor="#00ffff"
        app:sweepColor="#005644"
        app:sweepStep="20"
        app:startAngle="180"
         />
</LinearLayout>

案例四

继承View 并实现监听方法当用户点击时View中的数字+1

重写View的类CountView.java

package com.qf.sxy.customview04;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.View;

/**
 * Created by sxy on 2016/9/28.
 */
public class CountView extends View implements View.OnClickListener{

    private Paint mPaint;
    private int count =0;

    public CountView(Context context) {
        this(context,null);
    }

    public CountView(Context context, AttributeSet attrs) {
        this(context, attrs,0);
    }

    public CountView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        //初始化化画笔对象
        initPaint();
        //监听事件
        setOnClickListener(this);
    }

    private void initPaint(){
        mPaint = new Paint();
        mPaint.setAntiAlias(true);
        mPaint.setColor(Color.RED);
        mPaint.setTextSize(300);
    }


    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        //获取当前的数字字符串
        String countStr =String.valueOf(count);
        Rect rect = new Rect();
        //获取文字区域
        mPaint.getTextBounds(countStr,0,countStr.length(),rect);
        int strWith =  rect.width();
        int strHeight = rect.height();

        canvas.drawText(countStr,getWidth()/2-strWith/2,getHeight()/2+strHeight/2,mPaint);
    }


    //点击事件的监听
    @Override
    public void onClick(View v) {
        count++;
        invalidate();//刷新
    }
}

布局文件

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.qf.sxy.customview04.MainActivity">

    <com.qf.sxy.customview04.CountView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
</RelativeLayout>

案例五

说明 View上有一个点当用户点击或者移动时小点变色并且跟随移动

这里写图片描述

重写View的类BallView.java

package com.qf.sxy.customview05.widget;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;

import java.util.Random;

/**
 * Created by sxy on 2016/9/28.
 */
public class BallView extends View {

    private Paint mPaint;
    private int cx = 50,cy=50,radius = 20;//圆心x  圆心y  半径

    //小球颜色随机改变
    private int[] colors = {Color.BLACK,Color.BLUE,Color.DKGRAY,Color.GREEN,Color.RED,Color.YELLOW};


    private int pWith = 100,pHeight =100;
    public BallView(Context context) {
        this(context,null);
    }

    public BallView(Context context, AttributeSet attrs) {
        this(context, attrs,0);
    }

    public BallView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        //初始化画笔对象
        initPaint();
    }

    private void initPaint(){
        mPaint = new Paint();
        mPaint.setAntiAlias(true);
        mPaint.setColor(Color.RED);
    }

    //绘制  小球
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        //是否出界
        isOutSide();

        //随机获取颜色
        getBallColor();

        //绘制一个小球
        canvas.drawCircle(cx,cy,radius,mPaint);
    }

    private void isOutSide() {

        if(cx<radius){//左
            cx = radius;
        }
        if(cx>pWith-radius){//右
            cx = pWith-radius;
        }
        if(cy<radius){//上
            cy = radius;
        }
        if(cy>pHeight-radius){//下
            cy = pHeight-radius;
        }

    }


    private void getBallColor() {
        Random r = new Random();
        int color = r.nextInt(colors.length);
        mPaint.setColor(colors[color]);

    }


    @Override
    public boolean onTouchEvent(MotionEvent event) {
        switch (event.getAction()){
            case MotionEvent.ACTION_DOWN://按下事件
                cx = (int)event.getX();
                cy = (int)event.getY();
                invalidate();//刷新
                break;
            case MotionEvent.ACTION_MOVE://移动事件
                cx = (int)event.getX();
                cy = (int)event.getY();
                invalidate();//刷新
                break;
            case MotionEvent.ACTION_UP://抬起的事件
                cx = (int)event.getX();
                cy = (int)event.getY();
                invalidate();//刷新
                break;
        }
        //消费事件 不然会有问题
        return true;
    }


    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        pWith = MeasureSpec.getSize(widthMeasureSpec);
        pHeight = MeasureSpec.getSize(heightMeasureSpec);
    }
}

布局文件

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"

    tools:context="com.qf.sxy.customview05.MainActivity">

    <com.qf.sxy.customview05.widget.BallView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        />
</RelativeLayout>

案例6

说明重写EditText 并监听文本改变事件如果有字就在文本框右侧改变图片

这里写图片描述

MyEditText.java

package com.qf.sxy.customview06.widget;

import android.content.Context;
import android.graphics.drawable.Drawable;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.AttributeSet;
import android.widget.EditText;

import com.qf.sxy.customview06.R;

/**
 * Created by sxy on 2016/9/28.
 */
public class MyEditText extends EditText {

    Drawable drawable1;
    Drawable drawable2;
    public MyEditText(Context context) {
        this(context,null);
    }

    public MyEditText(Context context, AttributeSet attrs) {
        super(context, attrs);
        changeBitmap();
    }

    public MyEditText(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        //根据文本输入 修改图片
       // changeBitmap();
    }


    public void changeBitmap(){


        addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                //修改图片
                setBitmap();
            }

            @Override
            public void afterTextChanged(Editable s) {

            }
        });


        setBitmap();
    }

    //设置图片
    public void setBitmap(){
         drawable1 =getResources().getDrawable(R.mipmap.ic_launcher);
         drawable2 =getResources().getDrawable(R.mipmap.qq);

        if(length()>0){//设置一种图片
//            setFocusable(true);
            //左上右下
            setCompoundDrawablesWithIntrinsicBounds(null,null,drawable1,null);

        }else{//设置另一种图片
           // setFocusable(true);
//左上右下
            setCompoundDrawablesWithIntrinsicBounds(null,null,drawable2,null);
        }

    }


}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.qf.sxy.customview06.MainActivity">

    <com.qf.sxy.customview06.widget.MyEditText
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:enabled="true"

        android:hint="请输入姓名" />
    <com.qf.sxy.customview06.widget.MyEditText
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:hint="请输入密码"
       />
</LinearLayout>

案例7

说明继承EditText 设置一张背景图并且划线让其想一个笔记本

这里写图片描述

MyNoteView.java

package com.qf.sxy.customview07.widget;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.Gravity;
import android.widget.EditText;

import com.qf.sxy.customview07.R;

/**
 * Created by sxy on 2016/9/28.
 */
public class MyNoteView extends EditText {


    private int lineSpace = 50;//行间距
    private Paint mPaint ;
    private int linePadding = 60;//设置内边距
    private int lineColor = Color.RED;

    public MyNoteView(Context context) {
        super(context);
    }

    public MyNoteView(Context context, AttributeSet attrs) {
        super(context, attrs);

        //初始化画笔对象
        initPaint();


        TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.MyNoteView);
        if(array!=null){
            lineColor = array.getColor(R.styleable.MyNoteView_lineColor,Color.RED);
            linePadding = array.getInteger(R.styleable.MyNoteView_linePadding,60);
            lineSpace = array.getInteger(R.styleable.MyNoteView_lineSpace,60);
        }

        mPaint.setColor(lineColor);

        //设置行间距  参数1:间距  参数2:倍数
        setLineSpacing(lineSpace,1);
        //设置整个的内边距
        setPadding(linePadding,0,linePadding,0);
        //文字从顶部开始
        setGravity(Gravity.TOP);
    }


    public void initPaint(){
        mPaint = new Paint();
        mPaint.setAntiAlias(true);
        mPaint.setColor(Color.RED);
    }

    //绘制线
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        //获取View的高度
        int height = getHeight();
        //获取每一行的高度
        int lineHeight = getLineHeight();
        //得到总的线的数量
        int lineNum = height/lineHeight;

        for(int i=0;i<lineNum;i++){
            canvas.drawLine(linePadding,(i+1)*lineHeight,getWidth()-linePadding,(i+1)*lineHeight,mPaint);
        }

        //获取文本行数
        int linesCount = getLineCount();
        //画多余的部分
        for(int i = lineNum;i<linesCount;i++ ){
            canvas.drawLine(linePadding,i*lineHeight,getWidth()-linePadding,i*lineHeight,mPaint);
        }

    }
}

属性文件

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="MyNoteView">
        <attr name="lineSpace" format="integer|reference"></attr>
        <attr name="linePadding" format="integer|reference"></attr>
        <attr name="lineColor" format="color|reference"></attr>
    </declare-styleable>
</resources>

布局文件

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:context="com.qf.sxy.customview07.MainActivity">

    <com.qf.sxy.customview07.widget.MyNoteView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@mipmap/background"
        app:lineColor="#0000ff"
        app:linePadding="100"
        app:lineSpace="30"
        />
</RelativeLayout>

查看全文

相关阅读:
缓存
 mybatis(ibatis)理解
 hibernate理解
 linux vi 命令
 Activity中ConfigChanges属性的用法
 sendStickyBroadcast和sendStickyOrderedBroadcast
广播 BroadCastReceiver
Android四大基本组件介绍与生命周期
 ubuntu14.04 开机自动运行应用程序
 Android中BindService方式使用的理解

原文地址：https://www.cnblogs.com/muyuge/p/6152169.html

最新文章
游泳了，感觉很好
 uva 10817
LA 2038
LA 4727
poj 2311
poj 1704
poj 2348
POJ 2484
hdu 4725
POJ 2135