Android自定義進度條

Android原生控件只有橫向進度條一種，並且無法變換樣式，好比原生rom的樣子

很醜是吧，當偉大的產品設計要求更換前背景，甚至縱向，甚至圓弧狀的，咋辦，好比

ok，咱們開始吧：
一）變換前背景

先來看看progressbar的屬性：
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" />
根據style="?android:attr/progressBarStyleHorizontal"，咱們找到源碼中的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，繼續發掘源碼，找到drawable下面的progress_horizontal.xml，這就是咱們今天的主角了：

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
把這個文件複製到本身工程下的drawable，就能夠爲所欲爲的修改shape的屬性，漸變，圓角等等
那麼怎麼放一個圖片進去呢，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中指定你處理好的圖片
而後回到佈局中
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，四角仍是有圓倒角的，貌似是系統本身加上去的，總之個人圖片裏面是沒有作這個倒角處理的
二）縱向進度條

仍是得從源碼入手，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>
爲何shape外面要包一層clip呢，官方文檔解釋是clipdrawable是能夠自我複製的，來看看定義
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有兩個屬性，默認爲horizontal
android:gravity有兩個屬性，默認爲left
那咱們試試改爲vertical和bottom會有什麼效果，新建一個progress_vertical.xml，把源碼progress_horizontal.xml的內容複製過來，這裏去掉了secondaryProgress，修改了clip，shape的漸變中心centerY改成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>
佈局中android:progressDrawable="@drawable/progress_vertical"

  ok，搞定，就是這麼簡單：

三）弧形bar

這個也許算不上是進度條，用的也很少，最多也就儀表盤用用，否則誰會把進度條整成圓弧的呢。好吧這個可不是改改源碼就能搞定的，看代碼
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. } 
首先是一堆成員變量，兩個Paint用來畫圓弧一個前景一個背景，一個RectF圓弧就畫在上面，而後是一些控制參數好比sweep圓弧掃過的角度，xy座標等等
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);
設置兩個畫筆，顏色，寬度，樣式等等，BlurMaskFilter筆是邊緣模糊效果，有幾種，能夠本身嘗試
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.     }
重寫父類View的onSizeChanged，爲的是本身根據佈局中的大小作居中處理
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.     } 
重寫onDraw以便重繪canvas
drawSpeed裏面
經過計算mSweep = (float) mIncSpeedValue / mSpeedMax * 180;
而後canvas.drawArc(mOval, 180, mSweep, false, mArcPaint);
會根據mSweep的變化，畫出相應長度的弧度來
根據與閾值的對比，還能夠設定不一樣的 顏色：
if (mIncSpeedValue > mThreshold) {
   mArcPaint.setColor(0xFFFF0000);
  }
  else {
   mArcPaint.setColor(0xFF00B0F0);
  }
calcSpeed經過一個步進來控制增量或減量，以使弧度天然過渡，減小跳躍
ok，大功告成