Android自定義進度條
Android原生控件只有橫向進度條一種，而且沒法變換樣式，比如原生rom的樣子
![20120510021613222.jpg]()
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，比如![20120510021614352.png]()
ok，我們開始吧：
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"，我們找到源碼中的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，這就是我們今天的主角了：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
把這個文件複製到自己工程下的drawable，就可以隨心所欲的修改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
然後回到佈局中
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![20120510021614698.jpg]()
注意看，四角還是有圓倒角的，貌似是系統自己加上去的，總之我的圖片裏面是沒有做這個倒角處理的
二）縱向進度條
還是得從源碼入手，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>
爲什麼shape外面要包一層clip呢，官方文檔解釋是clipdrawable是可以自我複製的，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
那我們試試改成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改爲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：
![20120510021614152.jpg]()
三）弧形bar
這個也許算不上是進度條，用的也不多，最多也就儀表盤用用，不然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，然後是一些控制參數比如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，可以自己嘗試
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，爲的是自己根據佈局中的大小做居中處理
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
通過計算mSweep = (float) mIncSpeedValue / mSpeedMax * 180;
然後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，還可以設定不同的 顏色：
if (mIncSpeedValue > mThreshold) {
mArcPaint.setColor(0xFFFF0000);
}
else {
mArcPaint.setColor(0xFF00B0F0);
}
calcSpeed通過一個步進來控制增量或減量，以使弧度自然過渡，減少跳躍
ok，大功告成
![\]()
