Android4.1.1引起Cannot draw recycled bitmaps

在android4.1.1上運行以前寫的程式，出現如下異常：

java.lang.IllegalArgumentException: Cannot draw recycled bitmapsat android.view.GLES20Canvas.drawBitmap(GLES20Canvas.java:778)at android.view.GLES20RecordingCanvas.drawBitmap(GLES20RecordingCanvas.java:117)at android.graphics.drawable.BitmapDrawable.draw(BitmapDrawable.java:393)at
android.widget.ImageView.onDraw(ImageView.java:979)at android.view.View.draw(View.java:13458)at android.view.View.getDisplayList(View.java:12409)at android.view.View.getDisplayList(View.java:12453)at android.view.View.draw(View.java:13182)at android.view.ViewGroup.drawChild(ViewGroup.java:2929)at
android.view.ViewGroup.dispatchDraw(ViewGroup.java:2799)at android.view.View.draw(View.java:13461)at android.view.View.getDisplayList(View.java:12409)at android.view.View.getDisplayList(View.java:12453)at android.view.View.draw(View.java:13182)at android.view.ViewGroup.drawChild(ViewGroup.java:2929)at
android.widget.ListView.drawChild(ListView.java:3226)at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2799)at android.widget.AbsListView.dispatchDraw(AbsListView.java:2433)at android.widget.ListView.dispatchDraw(ListView.java:3221)at android.view.View.draw(View.java:13461)at
android.widget.AbsListView.draw(AbsListView.java:3759)

經分析，引起原因：

android4.0和android4.1的api差異，Bitmap在建立縮圖時，4.1.1的時候，若縮圖和原圖大小一樣，建立的縮圖會返回原圖，若原圖的bitmap人為的回收或者系統回收，就會引起此異常。

GLES20Canvas相關源碼如下：

android 4.0

    public void drawBitmap(Bitmap bitmap, float left, float top, Paint paint) {
        // Shaders are ignored when drawing bitmaps
        int modifiers = paint != null ? setupModifiers(bitmap, paint) : MODIFIER_NONE;
        final int nativePaint = paint == null ? 0 : paint.mNativePaint;
        nDrawBitmap(mRenderer, bitmap.mNativeBitmap, bitmap.mBuffer, left, top, nativePaint);
        if (modifiers != MODIFIER_NONE) nResetModifiers(mRenderer, modifiers);
    }

android4.1

    public void drawBitmap(Bitmap bitmap, float left, float top, Paint paint) {
        if (bitmap.isRecycled()) throw new IllegalArgumentException("Cannot draw recycled bitmaps");

        // Shaders are ignored when drawing bitmaps
        int modifiers = paint != null ? setupModifiers(bitmap, paint) : MODIFIER_NONE;
        try {
            final int nativePaint = paint == null ? 0 : paint.mNativePaint;
            nDrawBitmap(mRenderer, bitmap.mNativeBitmap, bitmap.mBuffer, left, top, nativePaint);
        } finally {
            if (modifiers != MODIFIER_NONE) nResetModifiers(mRenderer, modifiers);
        }
    }

因此，需要在以前寫的程式中，加入異常捕獲，程式才運行正常。