-
public class MainActivity extends Activity {
-
private ImageView mRevertImageView;
-
private Bitmap mSourceBitmap; //原图
-
private Bitmap mRevertBitmap; //倒立图
-
-
@Override
-
protected void onCreate(Bundle savedInstanceState) {
-
super.onCreate(savedInstanceState);
-
setContentView(R.layout.activity_main);
-
-
mRevertImageView = (ImageView)findViewById(R.id.im_revert);
-
mSourceBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.source);
-
mRevertImageView.setBackground(new BitmapDrawable(getResources(), revertBitmap(mSourceBitmap)));
-
}
-
-
private Bitmap revertBitmap(Bitmap originalImage) {
-
final int reflectionGap = 4;
-
int width = originalImage.getWidth();
-
int height = originalImage.getHeight();
-
Matrix matrix = new Matrix();
-
matrix.preScale(1, -1); //实现图片的反转
-
Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0, height / 2, width, height / 2, matrix, false); //创建反转后的图片Bitmap对象，图片高是原图的一半。
-
-
Bitmap bitmapWithReflection = Bitmap.createBitmap(width,
-
(height + height / 2), Config.ARGB_8888); //创建标准的Bitmap对象，宽和原图一致，高是原图的1.5倍。
-
Canvas canvas = new Canvas(bitmapWithReflection);
-
canvas.drawBitmap(originalImage, 0, 0, null); //创建画布对象，将原图画于画布，起点是原点位置。
-
Paint defaultPaint = new Paint();
-
canvas.drawRect(0, height, width, height + reflectionGap, defaultPaint);
-
canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null);//将反转后的图片画到画布中。
-
Paint paint = new Paint();
-
LinearGradient shader = new LinearGradient(0,
-
originalImage.getHeight(), 0, bitmapWithReflection.getHeight()
-
+ reflectionGap, 0×70ffffff, 0×00ffffff,
-
TileMode.MIRROR); //创建线性渐变LinearGradient 对象。
-
paint.setShader(shader);
-
paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
-
canvas.drawRect(0, height, width, bitmapWithReflection.getHeight()
-
+ reflectionGap, paint); //画布画出反转图片大小区域，然后把渐变效果加到其中，就出现了图片的倒影效果。
-
return bitmapWithReflection;
-
}
-
}
