Question

当我将一个Bitmap从SDCard转换为Drawable时，有一些奇怪的东西出现在调整大小上：

String sdDir = Environment.getExternalStorageDirectory().getPath();
String filename = "test.png"; //420px X 420px
Drawable tmpDraw;
Bitmap tmpBit = BitmapFactory.decodeFile(sdDir+filename);

Log.e("BAH","Bitmap height:"+tmpBit.getHeight()); //420

tmpDraw = (Drawable) new BitmapDrawable(getResources(),tmpBit);
int height = tmpDraw.getMinimumHeight();

Log.e("BAH","Drawable height:"+height); //420

我假设我需要一个参考点来扩展？如果从SDCard读取文件，它是否被归类为MDPI，这就是重新调整的原因？我目前正在使用Nexus 7来测试哪个是TVDPI。我希望缩放发生，好像Bitmap是HDPI。

任何建议都将不胜感激！

认为我已经破解了它：

String sdDir = Environment.getExternalStorageDirectory().getPath();
String filename = "test.png"; //420px X 420px
Drawable tmpDraw;

BitmapFactory.Options options = new BitmapFactory.Options();
DisplayMetrics metrics = getApplicationContext().getResources().getDisplayMetrics();
options.inDensity = 240; //Being DPI for HDPI
options.inTargetDensity=metrics.densityDpi; //Being current DPI
//inDensity/inTargetDensity are a ratio

Bitmap tmpBit = BitmapFactory.decodeFile(sdDir+filename,options);

Log.e("BAH","Bitmap height:"+tmpBit.getHeight()); //373 Correct for TVDPI

tmpDraw = (Drawable) new BitmapDrawable(getResources(),tmpBit);
int height = tmpDraw.getMinimumHeight();

Log.e("BAH","Drawable height:"+height); //373 Correct for TVDPI

这是一种可以接受的方式吗？

Answer 1

是的，你应该将Resources传递给BitmapDrawable构造函数，这样就不会搞砸了。

Android - 从SDCard将Bitmap转换为Drawable

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