自定义view

跟随当前点击位置

package com.view;

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;

public class Ontuch extends View {
    // 自定义X轴
    public float X;
    // 自定义Y轴
    public float Y;

    public Ontuch(Context context, AttributeSet attrs) {
        super(context, attrs);
        // TODO Auto-generated constructor stub
    }

    @Override
    protected void onDraw(Canvas canvas) {
        // TODO Auto-generated method stub
        super.onDraw(canvas);
        Paint paint = new Paint();
        paint.setTextSize(20);
        canvas.drawColor(Color.BLUE);
        // 设置园的X轴和Y轴用你点击到的位置
        canvas.drawCircle(X, Y, 20, paint);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        // TODO Auto-generated method stub

        this.Y = event.getY();// 获取X轴的位置
        this.X = event.getX();// 获取Y轴的位置
        this.invalidate();// 重绘当前对象
        return true;
    }
}

画图形

package com.view;

import android.R.color;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.provider.CalendarContract.Colors;
import android.util.AttributeSet;
import android.view.View;

public class CustomTitleView extends View {

    public CustomTitleView(Context context) {
        super(context);
        // TODO Auto-generated constructor stub
    }

    public CustomTitleView(Context context, AttributeSet attrs) {
        super(context, attrs);
        // TODO Auto-generated constructor stub
    }

    public CustomTitleView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        // TODO Auto-generated constructor stub
    }

    @Override
    protected void onDraw(Canvas canvas) {
        // TODO Auto-generated method stub
        super.onDraw(canvas);
        Paint p = new Paint();// 自定义画笔
        p.setColor(Color.BLUE);// 画笔的颜色
        p.setTextSize(30);// 画板中文字的大小
        p.setStrokeWidth(20);// 画板中线的宽度
        canvas.drawColor(Color.GREEN);// 画板的颜色
        canvas.drawLine(30, 50, 50, 500, p);// 画板中线的位置
        canvas.drawText("画板文字", 100, 100, p);// 画板文字 和文字所在的位置
        // 园所在的位置 第一个是距离左边多少 第二个是距离上边多少 第三个是园的大小
        canvas.drawCircle(10, 10, 50, p);

    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        // TODO Auto-generated method stub
        // super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        setMeasuredDimension(256, 358);// 画板的宽和高
    }

}

布局用法

<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=".MainActivity" >

    <com.view.CustomTitleView
        android:layout_width="300dp"
        android:layout_height="200dp"
        android:text="123" >
    </com.view.CustomTitleView>

    <com.view.Ontuch
        android:layout_width="match_parent"
        android:layout_height="match_parent" >
    </com.view.Ontuch>

</LinearLayout>