1、概述

 最近需要用进度条，秉着不重复造*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(); }

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); }

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(); }}

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>

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