Android 中ImageView处理图片的工具类

废话不多说，代码如下：

public class ImageUtil {

//放大缩小图片 
public static Bitmap zoomBitmap(Bitmap bitmap,int w,int h){ 
int width = bitmap.getWidth(); 
int height = bitmap.getHeight(); 
Matrix matrix = new Matrix(); 
float scaleWidht = ((float)w / width); 
float scaleHeight = ((float)h / height); 
matrix.postScale(scaleWidht, scaleHeight); 
Bitmap newbmp = Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, true); 
return newbmp; 
} 
//将Drawable转化为Bitmap 
public static Bitmap drawableToBitmap(Drawable drawable){ 
int width = drawable.getIntrinsicWidth(); 
int height = drawable.getIntrinsicHeight(); 
Bitmap bitmap = Bitmap.createBitmap(width, height, 
drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888 
: Bitmap.Config.RGB_565); 
Canvas canvas = new Canvas(bitmap); 
drawable.setBounds(0,0,width,height); 
drawable.draw(canvas); 
return bitmap;

}

//获得圆角图片的方法 
public static Bitmap getRoundedCornerBitmap(Bitmap bitmap,float roundPx){

Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap 
.getHeight(), Config.ARGB_8888); 
Canvas canvas = new Canvas(output);

final int color = 0xff424242; 
final Paint paint = new Paint(); 
final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight()); 
final RectF rectF = new RectF(rect);

paint.setAntiAlias(true); 
canvas.drawARGB(0, 0, 0, 0); 
paint.setColor(color); 
canvas.drawRoundRect(rectF, roundPx, roundPx, paint);

paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN)); 
canvas.drawBitmap(bitmap, rect, rect, paint);

return output; 
} 
//获得带倒影的图片方法 
public static Bitmap createReflectionImageWithOrigin(Bitmap bitmap){ 
final int reflectionGap = 4; 
int width = bitmap.getWidth(); 
int height = bitmap.getHeight();

Matrix matrix = new Matrix(); 
matrix.preScale(1, -1);

Bitmap reflectionImage = Bitmap.createBitmap(bitmap, 
0, height/2, width, height/2, matrix, false);

Bitmap bitmapWithReflection = Bitmap.createBitmap(width, (height + height/2), Config.ARGB_8888);

Canvas canvas = new Canvas(bitmapWithReflection); 
canvas.drawBitmap(bitmap, 0, 0, null); 
Paint deafalutPaint = new Paint(); 
canvas.drawRect(0, height,width,height + reflectionGap, 
deafalutPaint);

canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null);

Paint paint = new Paint(); 
LinearGradient shader = new LinearGradient(0, 
bitmap.getHeight(), 0, bitmapWithReflection.getHeight() 
+ reflectionGap, 0x70ffffff, 0x00ffffff, TileMode.CLAMP); 
paint.setShader(shader); 
// Set the Transfer mode to be porter duff and destination in 
paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN)); 
// Draw a rectangle using the paint with our linear gradient 
canvas.drawRect(0, height, width, bitmapWithReflection.getHeight() 
+ reflectionGap, paint);

return bitmapWithReflection; 
}

}