Android 打造形形色色的进度条 实现可以如此简单

转载请标明出处：http://blog.csdn.net/lmj623565791/article/details/43371299 ，本文出自：【张鸿洋的博客】

1、概述

最近需要用进度条，秉着不重复造轮子的原则，上github上搜索了一番，看了几个觉得比较好看的ProgressBar，比如：daimajia的等。简单看了下代码，基本都是继承自View，彻彻底底的自定义了一个进度条。盯着那绚丽滚动条，忽然觉得，为什么要通过View去写一个滚动条，系统已经提供了ProgressBar以及属于它的特性，我们没必要重新去构建一个，但是系统的又比较丑，不同版本变现还不一定一样。那么得出我们的目标：改变系统ProgressBar的样子。 

  对没错，我们没有必要去从0打造一个ProgressBar，人家虽然长的不好看，但是特性以及稳定性还是刚刚的，我们只需要为其整下容就ok了。 

说到整容，大家都知道我们的控件是通过onDraw()画出来的，那么我们只需要去覆盖它的onDraw()方法，自己写下就ok 。 

对了，我创建了一个微信公众号，欢迎关注，左边栏目上扫一扫即可。

  接下来，我们贴下效果图：

2、效果图

1、横向的进度条

2、圆形的进度条

没错，这就是我们的进度条效果，横向的模仿了daimajia的进度条样子。不过我们继承子ProgressBar，简单的为其整个容，代码清晰易懂 。为什么说，易懂呢？

横向那个进度条，大家会drawLine()和drawText()吧，那么通过getWidth()拿到控件的宽度，再通过getProgress()拿到进度，按比例控制绘制线的长短，字的位置还不是分分钟的事。

github源码地址：Android-ProgressBarWidthNumber欢迎大家star or fork 。

3、实现

横向的滚动条绘制肯定需要一些属性，比如已/未到达进度的颜色、宽度，文本的颜色、大小等。 
本来呢，我是想通过系统ProgressBar的progressDrawable，从里面提取一些属性完成绘制需要的参数的。但是，最终呢，反而让代码变得复杂。所以最终还是改用自定义属性。 说道自定义属性，大家应该已经不陌生了。

1、HorizontalProgressBarWithNumber

1、自定义属性

values/attr_progress_bar.xml:

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

    <declare-styleable name="HorizontalProgressBarWithNumber">
        <attr name="progress_unreached_color" format="color" />
        <attr name="progress_reached_color" format="color" />
        <attr name="progress_reached_bar_height" format="dimension" />
        <attr name="progress_unreached_bar_height" format="dimension" />
        <attr name="progress_text_size" format="dimension" />
        <attr name="progress_text_color" format="color" />
        <attr name="progress_text_offset" format="dimension" />
        <attr name="progress_text_visibility" format="enum">
            <enum name="visible" value="0" />
            <enum name="invisible" value="1" />
        </attr>
    </declare-styleable>

    <declare-styleable name="RoundProgressBarWidthNumber">
        <attr name="radius" format="dimension" />
    </declare-styleable>

</resources>

2、构造中获取

public class HorizontalProgressBarWithNumber extends ProgressBar
{

    private static final int DEFAULT_TEXT_SIZE = 10;
    private static final int DEFAULT_TEXT_COLOR = 0XFFFC00D1;
    private static final int DEFAULT_COLOR_UNREACHED_COLOR = 0xFFd3d6da;
    private static final int DEFAULT_HEIGHT_REACHED_PROGRESS_BAR = 2;
    private static final int DEFAULT_HEIGHT_UNREACHED_PROGRESS_BAR = 2;
    private static final int DEFAULT_SIZE_TEXT_OFFSET = 10;

    /**
     * painter of all drawing things
     */
    protected Paint mPaint = new Paint();
    /**
     * color of progress number
     */
    protected int mTextColor = DEFAULT_TEXT_COLOR;
    /**
     * size of text (sp)
     */
    protected int mTextSize = sp2px(DEFAULT_TEXT_SIZE);

    /**
     * offset of draw progress
     */
    protected int mTextOffset = dp2px(DEFAULT_SIZE_TEXT_OFFSET);

    /**
     * height of reached progress bar
     */
    protected int mReachedProgressBarHeight = dp2px(DEFAULT_HEIGHT_REACHED_PROGRESS_BAR);

    /**
     * color of reached bar
     */
    protected int mReachedBarColor = DEFAULT_TEXT_COLOR;
    /**
     * color of unreached bar
     */
    protected int mUnReachedBarColor = DEFAULT_COLOR_UNREACHED_COLOR;
    /**
     * height of unreached progress bar
     */
    protected int mUnReachedProgressBarHeight = dp2px(DEFAULT_HEIGHT_UNREACHED_PROGRESS_BAR);
    /**
     * view width except padding
     */
    protected int mRealWidth;

    protected boolean mIfDrawText = true;

    protected static final int VISIBLE = 0;

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

    public HorizontalProgressBarWithNumber(Context context, AttributeSet attrs,
            int defStyle)
    {
        super(context, attrs, defStyle);

        setHorizontalScrollBarEnabled(true);

        obtainStyledAttributes(attrs);

        mPaint.setTextSize(mTextSize);
        mPaint.setColor(mTextColor);

    }

    /**
     * get the styled attributes
     *
     * @param attrs
     */
    private void obtainStyledAttributes(AttributeSet attrs)
    {
        // init values from custom attributes
        final TypedArray attributes = getContext().obtainStyledAttributes(
                attrs, R.styleable.HorizontalProgressBarWithNumber);

        mTextColor = attributes
                .getColor(
                        R.styleable.HorizontalProgressBarWithNumber_progress_text_color,
                        DEFAULT_TEXT_COLOR);
        mTextSize = (int) attributes.getDimension(
                R.styleable.HorizontalProgressBarWithNumber_progress_text_size,
                mTextSize);

        mReachedBarColor = attributes
                .getColor(
                        R.styleable.HorizontalProgressBarWithNumber_progress_reached_color,
                        mTextColor);
        mUnReachedBarColor = attributes
                .getColor(
                        R.styleable.HorizontalProgressBarWithNumber_progress_unreached_color,
                        DEFAULT_COLOR_UNREACHED_COLOR);
        mReachedProgressBarHeight = (int) attributes
                .getDimension(
                        R.styleable.HorizontalProgressBarWithNumber_progress_reached_bar_height,
                        mReachedProgressBarHeight);
        mUnReachedProgressBarHeight = (int) attributes
                .getDimension(
                        R.styleable.HorizontalProgressBarWithNumber_progress_unreached_bar_height,
                        mUnReachedProgressBarHeight);
        mTextOffset = (int) attributes
                .getDimension(
                        R.styleable.HorizontalProgressBarWithNumber_progress_text_offset,
                        mTextOffset);

        int textVisible = attributes
                .getInt(R.styleable.HorizontalProgressBarWithNumber_progress_text_visibility,
                        VISIBLE);
        if (textVisible != VISIBLE)
        {
            mIfDrawText = false;
        }
        attributes.recycle();
    }

嗯，看起来代码挺长，其实都是在获取自定义属性，没什么技术含量。

3、onMeasure

刚才不是出onDraw里面写写就行了么，为什么要改onMeasure呢，主要是因为我们所有的属性比如进度条宽度让用户自定义了，所以我们的测量也得稍微变下。

@Override
protected synchronized void onMeasure(int widthMeasureSpec,
        int heightMeasureSpec)
{
    int heightMode = MeasureSpec.getMode(heightMeasureSpec);

    if (heightMode != MeasureSpec.EXACTLY)
    {

        float textHeight = (mPaint.descent() + mPaint.ascent());
        int exceptHeight = (int) (getPaddingTop() + getPaddingBottom() + Math
                .max(Math.max(mReachedProgressBarHeight,
                        mUnReachedProgressBarHeight), Math.abs(textHeight)));

        heightMeasureSpec = MeasureSpec.makeMeasureSpec(exceptHeight,
                MeasureSpec.EXACTLY);
    }
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);

}

宽度我们不变，所以的自定义属性不涉及宽度，高度呢，只考虑不是EXACTLY的情况（用户明确指定了，我们就不管了），根据padding和进度条宽度算出自己想要的，如果非EXACTLY下，我们进行exceptHeight封装，传入给控件进行测量高度。

测量完，就到我们的onDraw了~~~

4、onDraw

@Override
    protected synchronized void onDraw(Canvas canvas)
    {
        canvas.save();
        //画笔平移到指定paddingLeft， getHeight() / 2位置，注意以后坐标都为以此为0，0
        canvas.translate(getPaddingLeft(), getHeight() / 2);

        boolean noNeedBg = false;
        //当前进度和总值的比例
        float radio = getProgress() * 1.0f / getMax();
        //已到达的宽度
        float progressPosX = (int) (mRealWidth * radio);
        //绘制的文本
        String text = getProgress() + "%";

        //拿到字体的宽度和高度
        float textWidth = mPaint.measureText(text);
        float textHeight = (mPaint.descent() + mPaint.ascent()) / 2;

        //如果到达最后，则未到达的进度条不需要绘制
        if (progressPosX + textWidth > mRealWidth)
        {
            progressPosX = mRealWidth - textWidth;
            noNeedBg = true;
        }

        // 绘制已到达的进度
        float endX = progressPosX - mTextOffset / 2;
        if (endX > 0)
        {
            mPaint.setColor(mReachedBarColor);
            mPaint.setStrokeWidth(mReachedProgressBarHeight);
            canvas.drawLine(0, 0, endX, 0, mPaint);
        }

        // 绘制文本
        if (mIfDrawText)
        {
            mPaint.setColor(mTextColor);
            canvas.drawText(text, progressPosX, -textHeight, mPaint);
        }

        // 绘制未到达的进度条
        if (!noNeedBg)
        {
            float start = progressPosX + mTextOffset / 2 + textWidth;
            mPaint.setColor(mUnReachedBarColor);
            mPaint.setStrokeWidth(mUnReachedProgressBarHeight);
            canvas.drawLine(start, 0, mRealWidth, 0, mPaint);
        }

        canvas.restore();

    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh)
    {
        super.onSizeChanged(w, h, oldw, oldh);
        mRealWidth = w - getPaddingRight() - getPaddingLeft();

    }

其实核心方法就是onDraw了，但是呢，onDraw也很简单，绘制线、绘制文本、绘制线，结束。

还有两个简单的辅助方法：

/**
 * dp 2 px
 *
 * @param dpVal
 */
protected int dp2px(int dpVal)
{
    return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
            dpVal, getResources().getDisplayMetrics());
}

/**
 * sp 2 px
 *
 * @param spVal
 * @return
 */
protected int sp2px(int spVal)
{
    return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP,
            spVal, getResources().getDisplayMetrics());

}

好了，到此我们的横向进度就结束了，是不是很简单~~如果你是自定义View，你还得考虑progress的更新，考虑状态的销毁与恢复等等复杂的东西。

接下来看我们的RoundProgressBarWidthNumber圆形的进度条。

2、RoundProgressBarWidthNumber 

圆形的进度条和横向的进度条基本变量都是一致的，于是我就让RoundProgressBarWidthNumber extends HorizontalProgressBarWithNumber 了。

然后需要改变的就是测量和onDraw了：

完整代码：

package com.zhy.view;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Paint.Cap;
import android.graphics.Paint.Style;
import android.graphics.RectF;
import android.util.AttributeSet;

import com.zhy.library.view.R;

public class RoundProgressBarWidthNumber extends
        HorizontalProgressBarWithNumber {
    /**
     * mRadius of view
     */
    private int mRadius = dp2px(30);

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

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

        mReachedProgressBarHeight = (int) (mUnReachedProgressBarHeight * 2.5f);
        TypedArray ta = context.obtainStyledAttributes(attrs,
                R.styleable.RoundProgressBarWidthNumber);
        mRadius = (int) ta.getDimension(
                R.styleable.RoundProgressBarWidthNumber_radius, mRadius);
        ta.recycle();

        mTextSize = sp2px(14);

        mPaint.setStyle(Style.STROKE);
        mPaint.setAntiAlias(true);
        mPaint.setDither(true);
        mPaint.setStrokeCap(Cap.ROUND);

    }

    @Override
    protected synchronized void onMeasure(int widthMeasureSpec,
            int heightMeasureSpec) {
        int heightMode = MeasureSpec.getMode(heightMeasureSpec);
        int widthMode = MeasureSpec.getMode(widthMeasureSpec);

        int paintWidth = Math.max(mReachedProgressBarHeight,
                mUnReachedProgressBarHeight);

        if (heightMode != MeasureSpec.EXACTLY) {

            int exceptHeight = (int) (getPaddingTop() + getPaddingBottom()
                    + mRadius * 2 + paintWidth);
            heightMeasureSpec = MeasureSpec.makeMeasureSpec(exceptHeight,
                    MeasureSpec.EXACTLY);
        }
        if (widthMode != MeasureSpec.EXACTLY) {
            int exceptWidth = (int) (getPaddingLeft() + getPaddingRight()
                    + mRadius * 2 + paintWidth);
            widthMeasureSpec = MeasureSpec.makeMeasureSpec(exceptWidth,
                    MeasureSpec.EXACTLY);
        }

        super.onMeasure(heightMeasureSpec, heightMeasureSpec);

    }

    @Override
    protected synchronized void onDraw(Canvas canvas) {

        String text = getProgress() + "%";
        // mPaint.getTextBounds(text, 0, text.length(), mTextBound);
        float textWidth = mPaint.measureText(text);
        float textHeight = (mPaint.descent() + mPaint.ascent()) / 2;

        canvas.save();
        canvas.translate(getPaddingLeft(), getPaddingTop());
        mPaint.setStyle(Style.STROKE);
        // draw unreaded bar
        mPaint.setColor(mUnReachedBarColor);
        mPaint.setStrokeWidth(mUnReachedProgressBarHeight);
        canvas.drawCircle(mRadius, mRadius, mRadius, mPaint);
        // draw reached bar
        mPaint.setColor(mReachedBarColor);
        mPaint.setStrokeWidth(mReachedProgressBarHeight);
        float sweepAngle = getProgress() * 1.0f / getMax() * 360;
        canvas.drawArc(new RectF(0, 0, mRadius * 2, mRadius * 2), 0,
                sweepAngle, false, mPaint);
        // draw text
        mPaint.setStyle(Style.FILL);
        canvas.drawText(text, mRadius - textWidth / 2, mRadius - textHeight,
                mPaint);

        canvas.restore();

    }

}

首先获取它的专有属性mRadius，然后根据此属性去测量，测量完成绘制；

绘制的过程呢？

先绘制一个细一点的圆，然后绘制一个粗一点的弧度，二者叠在一起就行。文本呢，绘制在中间~~~总体，没什么代码量。

好了，两个进度条就到这了，是不是发现简单很多。总体设计上，存在些问题，如果抽取一个BaseProgressBar用于获取公共的属性；然后不同样子的进度条继承分别实现自己的测量和样子，这样结构可能会清晰些~~~

4、使用

布局文件

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:zhy="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:padding="25dp" >

        <com.zhy.view.HorizontalProgressBarWithNumber
            android:id="@+id/id_progressbar01"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="50dip"
            android:padding="5dp" />



        <com.zhy.view.HorizontalProgressBarWithNumber
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="50dip"
            android:padding="5dp"
            android:progress="50"
            zhy:progress_text_color="#ffF53B03"
            zhy:progress_unreached_color="#ffF7C6B7" />

        <com.zhy.view.RoundProgressBarWidthNumber
            android:id="@+id/id_progress02"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="50dip"
            android:padding="5dp"
            android:progress="30" />

        <com.zhy.view.RoundProgressBarWidthNumber
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="50dip"
            android:padding="5dp"
            android:progress="50"
            zhy:progress_reached_bar_height="20dp"
            zhy:progress_text_color="#ffF53B03"
            zhy:radius="60dp" />

    </LinearLayout>

</ScrollView>

MainActivity

package com.zhy.sample.progressbar;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;

import com.zhy.annotation.Log;
import com.zhy.view.HorizontalProgressBarWithNumber;

public class MainActivity extends Activity {

    private HorizontalProgressBarWithNumber mProgressBar;
    private static final int MSG_PROGRESS_UPDATE = 0x110;

    private Handler mHandler = new Handler() {
        @Log
        public void handleMessage(android.os.Message msg) {
            int progress = mProgressBar.getProgress();
            mProgressBar.setProgress(++progress);
            if (progress >= 100) {
                mHandler.removeMessages(MSG_PROGRESS_UPDATE);

            }
            mHandler.sendEmptyMessageDelayed(MSG_PROGRESS_UPDATE, 100);
        };
    };

    @Log
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mProgressBar = (HorizontalProgressBarWithNumber) findViewById(R.id.id_progressbar01);
        mHandler.sendEmptyMessage(MSG_PROGRESS_UPDATE);

    }

}

最后，本篇博客的目的呢？就是为了说下，类似ProgressBar这样的控件，如果你只是想去改变显示的样子，完全没必要从0去创建，复写onDraw即可，当然是个人观点，提出供大家参考。

源码点击下载