android 图片缩放与旋转

一．装载图片

BitmapFactory.decodeFile(pathName);

二．缩放图片

Matrix matrix = new Matrix();  
matrix.reset();
float scaleWidth = ((float) 320) / bitmap.getWidth();
float scaleHeight = ((float) 240) / bitmap.getHeight();
matrix.postScale(scaleWidth, scaleHeight);
bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);

三．旋转图片

Matrix matrix = new Matrix(); 
matrix.reset();
matrix.postRotate(180);
bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix,true);

四．保存图片

File file = new File(path);
FileOutputStream outStream = null;
try
{
outStream = new FileOutputStream(file);
bitmap.compress(CompressFormat.JPEG, 100, outStream);
   outStream.close();
}
catch (Exception e)
{
e.printStackTrace();
}

标签：Matrix,缩放,float,outStream,bitmap,new,android,旋转,matrix
来源： https://blog.51cto.com/u_15298588/3034034