Android自定义进度条

浏览数：22 / 时间：2015年06月11日

Android原生控件只有横向进度条一种，而且没法变换样式，比如原生rom的样子

很丑是吧，当伟大的产品设计要求更换前背景，甚至纵向，甚至圆弧状的，咋办，比如

ok，我们开始吧：

一）变换前背景

先来看看progressbar的属性：
1. <ProgressBar
2.             android:id="@+id/progressBar"
3.             style="?android:attr/progressBarStyleHorizontal"
4.             android:layout_width="match_parent"
5.             android:layout_height="wrap_content"
6.             android:layout_margin="5dip"
7.             android:layout_toRightOf="@+id/progressBarV"
8.             android:indeterminate="false"
9.             android:padding="2dip"
10.             android:progress="50" />
根据style="?android:attr/progressBarStyleHorizontal"，我们找到源码中的style.xml
1. <style name="Widget.ProgressBar.Horizontal">
2.         <item name="android:indeterminateOnly">false</item>
3.         <item name="android:progressDrawable">@android:drawable/progress_horizontal</item>
4.         <item name="android:indeterminateDrawable">@android:drawable/progress_indeterminate_horizontal</item>
5.         <item name="android:minHeight">20dip</item>
6.         <item name="android:maxHeight">20dip</item>
7.     </style>
看到
<item name="android:progressDrawable">@android:drawable/progress_horizontal</item>
木有，继续发掘源码，找到drawable下面的progress_horizontal.xml，这就是我们今天的主角了：

1. <layer-list xmlns:android="http://schemas.android.com/apk/res/android">
2.
3.     <item android:id="@android:id/background">
4.         <shape>
5.             <corners android:radius="5dip" />
6.             <gradient
7.                     android:startColor="#ff9d9e9d"
8.                     android:centerColor="#ff5a5d5a"
9.                     android:centerY="0.75"
10.                     android:endColor="#ff747674"
11.                     android:angle="270"
12.             />
13.         </shape>
14.     </item>
15.
16.     <item android:id="@android:id/secondaryProgress">
17.         <clip>
18.             <shape>
19.                 <corners android:radius="5dip" />
20.                 <gradient
21.                         android:startColor="#80ffd300"
22.                         android:centerColor="#80ffb600"
23.                         android:centerY="0.75"
24.                         android:endColor="#a0ffcb00"
25.                         android:angle="270"
26.                 />
27.             </shape>
28.         </clip>
29.     </item>
30.
31.     <item android:id="@android:id/progress">
32.         <clip>
33.             <shape>
34.                 <corners android:radius="5dip" />
35.                 <gradient
36.                         android:startColor="#ffffd300"
37.                         android:centerColor="#ffffb600"
38.                         android:centerY="0.75"
39.                         android:endColor="#ffffcb00"
40.                         android:angle="270"
41.                 />
42.             </shape>
43.         </clip>
44.     </item>
45.
46. </layer-list>
看到android:id="@android:id/progress"木有，看到android:id="@android:id/secondaryProgress"木有
把这个文件复制到自己工程下的drawable，就可以随心所欲的修改shape的属性，渐变，圆角等等
那么怎么放一个图片进去呢，ok，新建progress_horizontal1.xml：
1. <?xml version="1.0" encoding="utf-8"?>
2. <layer-list xmlns:android="http://schemas.android.com/apk/res/android">
3.
4.     <item android:id="@android:id/progress" android:drawable="@drawable/progressbar" />
5.
6. </layer-list>
在android:drawable中指定你处理好的图片
然后回到布局中
1. <ProgressBar
2.             android:id="@+id/progressBar1"
3.             android:layout_width="match_parent"
4.             android:layout_height="wrap_content"
5.             android:layout_below="@+id/progressBar"
6.             android:layout_margin="5dip"
7.             android:layout_toRightOf="@+id/progressBarV"
8.             android:background="@drawable/progress_bg"
9.             android:indeterminate="false"
10.             android:indeterminateOnly="false"
11.             android:maxHeight="20dip"
12.             android:minHeight="20dip"
13.             android:padding="2dip"
14.             android:progress="50"
15.             android:progressDrawable="@drawable/progress_horizontal1" />
android:background="@drawable/progress_bg"指定背景

android:progressDrawable="@drawable/progress_horizontal1"前景使用上面的progress_horizontal1
ok，搞定

注意看，四角还是有圆倒角的，貌似是系统自己加上去的，总之我的图片里面是没有做这个倒角处理的

二）纵向进度条

还是得从源码入手，看回progress_horizontal.xml
1. <item android:id="@android:id/progress">
2.         <clip>
3.             <shape>
4.                 <corners android:radius="5dip" />
5.                 <gradient
6.                         android:startColor="#ffffd300"
7.                         android:centerColor="#ffffb600"
8.                         android:centerY="0.75"
9.                         android:endColor="#ffffcb00"
10.                         android:angle="270"
11.                 />
12.             </shape>
13.         </clip>
14.     </item>
为什么shape外面要包一层clip呢，官方文档解释是clipdrawable是可以自我复制的，来看看定义
1. <?xml version="1.0" encoding="utf-8"?>
2. <clip
3.     xmlns:android="http://schemas.android.com/apk/res/android"
4.     android:drawable="@drawable/drawable_resource"
5.     android:clipOrientation=["horizontal" | "vertical"]
6.     android:gravity=["top" | "bottom" | "left" | "right" | "center_vertical" |
7.                      "fill_vertical" | "center_horizontal" | "fill_horizontal" |
8.                      "center" | "fill" | "clip_vertical" | "clip_horizontal"] />
android:clipOrientation有两个属性，默认为horizontal
android:gravity有两个属性，默认为left
那我们试试改成vertical和bottom会有什么效果，新建一个progress_vertical.xml，把源码progress_horizontal.xml的内容复制过来，这里去掉了secondaryProgress，修改了clip，shape的渐变中心centerY改为centerX
1. <item android:id="@android:id/progress">
2.         <clip
3.             android:clipOrientation="vertical"
4.             android:gravity = "bottom">
5.             <shape>
6.                 <corners android:radius="5dip" />
7.                 <gradient
8.                         android:startColor="#ffffd300"
9.                         android:centerColor="#ffffb600"
10.                         android:centerX="0.75"
11.                         android:endColor="#ffffcb00"
12.                         android:angle="90"
13.                 />
14.             </shape>
15.         </clip>
16.     </item>
布局中android:progressDrawable="@drawable/progress_vertical"

ok，搞定，就是这么简单：

三）弧形bar

这个也许算不上是进度条，用的也不多，最多也就仪表盘用用，不然谁会把进度条整成圆弧的呢。好吧这个可不是改改源码就能搞定的，看代码
1. public class Arcs extends View {
2.     private Paint mArcPaint;
3.     private Paint mArcBGPaint;
4.
5.     private RectF mOval;
6.     private float mSweep = 0;
7.     private int mSpeedMax = 200;
8.     private int mThreshold = 100;
9.     private int mIncSpeedValue = 0;
10.     private int mCurrentSpeedValue = 0;
11.     private float mCenterX;
12.     private float mCenterY;
13.     private float mSpeedArcWidth;
14.
15.     private final float SPEED_VALUE_INC = 2;
16.
17.     ..........
18.
19. }
首先是一堆成员变量，两个Paint用来画圆弧一个前景一个背景，一个RectF圆弧就画在上面，然后是一些控制参数比如sweep圆弧扫过的角度，xy坐标等等

1. mArcPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
2.         mArcPaint.setStyle(Paint.Style.STROKE);
3.         mArcPaint.setStrokeWidth(mSpeedArcWidth);
4. //        mPaint.setStrokeCap(Paint.Cap.ROUND);
5.         mArcPaint.setColor(0xff81ccd6);
6.         BlurMaskFilter mBlur = new BlurMaskFilter(8, BlurMaskFilter.Blur.INNER);
7.         mArcPaint.setMaskFilter(mBlur);
8.
9.         mArcBGPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
10.         mArcBGPaint.setStyle(Paint.Style.STROKE);
11.         mArcBGPaint.setStrokeWidth(mSpeedArcWidth+8);
12.         mArcBGPaint.setColor(0xff171717);
13.
14.         BlurMaskFilter mBGBlur = new BlurMaskFilter(8, BlurMaskFilter.Blur.INNER);
15.       mArcBGPaint.setMaskFilter(mBGBlur);
设置两个画笔，颜色，宽度，样式等等，BlurMaskFilter笔是边缘模糊效果，有几种，可以自己尝试

1. @Override
2. protected void onSizeChanged(int w, int h, int ow, int oh) {
3.         super.onSizeChanged(w, h, ow, oh);
4.         Log.i("onSizeChanged w", w+"");
5.         Log.i("onSizeChanged h", h+"");
6.         mCenterX = w * 0.5f; // remember the center of the screen
7.         mCenterY = h - mSpeedArcWidth;
8.         mOval = new RectF(mCenterX - mCenterY, mSpeedArcWidth, mCenterX + mCenterY, mCenterY * 2);
9.     }
重写父类View的onSizeChanged，为的是自己根据布局中的大小做居中处理

1. @Override
2.     protected void onDraw(Canvas canvas) {
3.         drawSpeed(canvas);
4.         calcSpeed();
5.     }
6.
7. private void drawSpeed(Canvas canvas) {
8.         canvas.drawArc(mOval, 179, 181, false, mArcBGPaint);
9.
10.         mSweep = (float) mIncSpeedValue / mSpeedMax * 180;
11.         if (mIncSpeedValue > mThreshold) {
12.             mArcPaint.setColor(0xFFFF0000);
13.         }
14.         else {
15.             mArcPaint.setColor(0xFF00B0F0);
16.         }
17.
18.         canvas.drawArc(mOval, 180, mSweep, false, mArcPaint);
19.     }
20.
21. private void calcSpeed() {
22.         if (mIncSpeedValue < mCurrentSpeedValue) {
23.             mIncSpeedValue += SPEED_VALUE_INC;
24.             if (mIncSpeedValue > mCurrentSpeedValue) {
25.                 mIncSpeedValue = mCurrentSpeedValue;
26.             }
27.             invalidate();
28.         }
29.         else if (mIncSpeedValue > mCurrentSpeedValue) {
30.             mIncSpeedValue -= SPEED_VALUE_INC;
31.             if (mIncSpeedValue < mCurrentSpeedValue) {
32.                 mIncSpeedValue = mCurrentSpeedValue;
33.             }
34.             invalidate();
35.         }
36.     }
重写onDraw以便重绘canvas
drawSpeed里面
通过计算mSweep = (float) mIncSpeedValue / mSpeedMax * 180;
然后canvas.drawArc(mOval, 180, mSweep, false, mArcPaint);
会根据mSweep的变化，画出相应长度的弧度来
根据与阈值的对比，还可以设定不同的颜色：

if (mIncSpeedValue > mThreshold) {
   mArcPaint.setColor(0xFFFF0000);
  }
  else {
   mArcPaint.setColor(0xFF00B0F0);
  }

calcSpeed通过一个步进来控制增量或减量，以使弧度自然过渡，减少跳跃
ok，大功告成