转载自 http://blog.sina.com.cn/s/blog_82f640ed010166ub.html

在CTS Android Hole测试24个failed，查看错误如下：

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11-15 15:39:53 I/0123456789ABCDEF:android.holo.cts.HoloTest#testHolo FAIL
junit.framework.AssertionFailedError: Failed bitmap names:[holo_button, holo_button_pressed, holo_progressbar,holo_progressbar_small, holo_progressbar_large,holo_radiogroup_vertical, holo_ratingbar_0, holo_ratingbar_2point5,holo_ratingbar_5, holo_ratingbar_0_pressed,holo_ratingbar_2point5_pressed, holo_ratingbar_5_pressed,holo_searchview, holo_searchview_query, holo_searchview_query_hint,holo_seekbar_0, holo_seekbar_50, holo_seekbar_100, holo_switch,holo_switch_checked, holo_tabhost, holo_toggle_button,holo_toggle_button_checked] Check/mnt/sdcard/cts-holo-assets/failed and/mnt/sdcard/cts-holo-assets/diff for details.
at android.holo.cts.HoloTest.runThemeTest(HoloTest.java:143)
at android.holo.cts.HoloTest.testHolo(HoloTest.java:35)
at java.lang.reflect.Method.invokeNative(Native Method)
atandroid.test.InstrumentationTestCase.runMethod(InstrumentationTestCase.java:214)
atandroid.test.InstrumentationTestCase.runTest(InstrumentationTestCase.java:199)
atandroid.test.ActivityInstrumentationTestCase2.runTest(ActivityInstrumentationTestCase2.java:192)
atandroid.test.AndroidTestRunner.runTest(AndroidTestRunner.java:190)
atandroid.test.AndroidTestRunner.runTest(AndroidTestRunner.java:175)
atandroid.test.InstrumentationTestRunner.onStart(InstrumentationTestRunner.java:555)
atandroid.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1584)

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花了一个周的时间，终于把Android.hole Test分析清楚，解决了这个问题.

所有源代码路径：

cts\tests\tests\holo\src\android\holo\cts

framework\base\core\java\android\view\

1. Holo测试原理：

1.1)  holoTest启动正常启动自带theme(主题)

runThemeTest(HoloTest.java)->startActivityForResult(ThemeTestActivity.java)->setTheme(LayoutTestActivity.java)->initializeTheme(ContextThemeWrapper.java)

1.2)  快照保存当前主题theme的元素（比如button，textEdit等）比较快照获得元素bitmap和referrencebitmap，判断是否一致，如果一致测试通过，如果不一致，测试失败

protected voidonPreExecute() {

mBitmap =getBitmap();

mReferenceBitmap =BitmapAssets.getBitmap(getApplicationContext(),mBitmapName);

final int threshold = 1;

mSame = compareTo(mBitmap, mReferenceBitmap, threshold);

}

private booleancompareTo(Bitmap bitmap, Bitmap reference, int threshold){

if(bitmap.getConfig() != reference.getConfig() ||

bitmap.getWidth() != reference.getWidth() ||

bitmap.getHeight() != reference.getHeight()) {

return false;

}

int w =bitmap.getWidth();

int h =bitmap.getHeight();

ByteBufferbuffer1 = ByteBuffer.allocate(bitmap.getByteCount());

ByteBufferbuffer2 = ByteBuffer.allocate(reference.getByteCount());

bitmap.copyPixelsToBuffer(buffer1);

reference.copyPixelsToBuffer(buffer2);

final int length= w*h;

for (int i = 0; i< length; i++) {

int pel1 = buffer1.getInt(i);

intpel2 = buffer2.getInt(i);

int dr = (pel1 & 0x000000FF) - (pel2 &0x000000FF);

int dg = ((pel1 & 0x0000FF00) - (pel2 & 0x0000FF00))>> 8;

int db = ((pel1 & 0x00FF0000) - (pel2 & 0x00FF0000))>> 16;

//在这里比较图片，注意表示的颜色

if (Math.abs(db) > threshold ||

Math.abs(dg) > threshold ||

Math.abs(dr) > threshold) {

return false;

}

if (bitmap.hasAlpha()) {

int da = ((pel1 & 0xFF000000) - (pel2 & 0xFF000000))>> 24;

if (Math.abs(da) > threshold) {

Log.i(TAG, "++++++++compareTo 3 ++++++++++" );

returnfalse;

}

}

}

Log.i(TAG, "++++++++compareTo 4 ++++++++++" );

return true;

}

Referrencebitmap在哪里？

cts\tests\tests\holo\res 里面的drawable， 里面是不是有好多drawable啊，你知道为什么吗？懂得应用程序开发的估计都知道，这个就是为了适应各种LCD尺寸和denisity的。（这个很重要哦）

1.3） 如果两个bitmap不一致，就保存到手机上 /mnt/sdcard/diff 和/mnt/sdcard/failed两个文件夹里面。

saveBitmap(LayoutTestActivity.java) ->  BitmapAssets.saveBitmap(BitmapAssets.java)

显示效果图如下：

注意红色表示的就是两个bitmap差异之处，具体看源代码。

2. 测试原因分析

在网上查找了几天，用百度没有搜索出任何有用信息，最后还是google出大拿的一话，恍然大悟：

Android.hool test failed depends onscreen type and dpi, this test still fail with 1280x720 resolutionwith density 320, but can pass with density 240.

原来我的手机屏幕是1280x720 320dpi的，所以显示效果会有差异，导致失败了。

3. 解决办法

# vimdevice/xxx/system.prop

rild.libpath=/system/lib/libreference-ril.so

rild.libargs=-d /dev/ttyS0

ro.sf.lcd_density=320

修改其中ro.sf.lcd_density=240

重新烧录编译img文件下载，重新测试，结果如下：

11-15 15:03:56 I:android.holo.cts.HoloTest#testHolo PASS

11-15 15:05:06 I:android.holo.cts.HoloTest#testHoloDialog PASS

11-15 15:06:13 I/emulator-5554:android.holo.cts.HoloTest#testHoloDialogMinimumWidthPASS

11-15 15:07:17 I:android.holo.cts.HoloTest#testHoloDialogNoActionBar PASS

11-15 15:08:24 I/emulator-5554:android.holo.cts.HoloTest#testHoloDialogNoActionBarMinimumWidthPASS

11-15 15:09:31 I:android.holo.cts.HoloTest#testHoloDialogWhenLarge PASS

11-15 15:10:40 I/emulator-5554:android.holo.cts.HoloTest#testHoloDialogWhenLargeNoActionBarPASS

11-15 15:11:41 I:android.holo.cts.HoloTest#testHoloInputMethod PASS

11-15 15:12:53 I:android.holo.cts.HoloTest#testHoloLight PASS

11-15 15:14:04 I:android.holo.cts.HoloTest#testHoloLightDarkActionBarPASS

11-15 15:15:12 I:android.holo.cts.HoloTest#testHoloLightDialog PASS

11-15 15:16:20 I:android.holo.cts.HoloTest#testHoloLightDialogMinimumWidthPASS

11-15 15:17:24 I:android.holo.cts.HoloTest#testHoloLightDialogNoActionBarPASS

11-15 15:18:31 I:android.holo.cts.HoloTest#testHoloLightDialogNoActionBarMinimumWidthPASS

11-15 15:19:42 I:android.holo.cts.HoloTest#testHoloLightDialogWhenLargePASS

11-15 15:20:54 I/:android.holo.cts.HoloTest#testHoloLightDialogWhenLargeNoActionBarPASS

11-15 15:22:06 I/:android.holo.cts.HoloTest#testHoloLightNoActionBar PASS

11-15 15:23:17 I/:android.holo.cts.HoloTest#testHoloLightNoActionBarFullscreenPASS

11-15 15:24:18 I/:android.holo.cts.HoloTest#testHoloLightPanel PASS

11-15 15:25:26 I/:android.holo.cts.HoloTest#testHoloNoActionBar PASS

11-15 15:26:36 I/:android.holo.cts.HoloTest#testHoloNoActionBarFullscreenPASS

11-15 15:27:36 I:android.holo.cts.HoloTest#testHoloPanel PASS

11-15 15:28:49 I:android.holo.cts.HoloTest#testHoloWallpaper PASS

11-1515:30:01 I: android.holo.cts.HoloTest#testHoloWallpaperNoTitleBarPASS

4. 补充

还有一种办法是，可以生成支持1280x720 320dpi的holo ReferrenceBitmap,就是增加一个res/drawable-xxx 文件夹,具体看HoloTestUtilitiesActivity.java。这个我还没有花时间研究，谁有兴趣可以看看。