Android 打造形形色色的进度条 实现可以如此简单

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