Android 设置图片倒影效果

首先，贴出效果图：

1.布局文件main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />

    <ImageView
        android:id="@+id/picture_qian"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:src="@drawable/horse" />

</LinearLayout>

2.MainActivity界面java代码：

package com.easymorse.picture;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.LinearGradient;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.graphics.Shader.TileMode;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.widget.ImageView;

public class MainActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        ImageView imageView2 = (ImageView) findViewById(R.id.picture_qian);

        Bitmap bmp = ((BitmapDrawable) getResources().getDrawable(
                R.drawable.horse)).getBitmap();

        imageView2.setImageBitmap(createReflectedImage(bmp));
    }

    public static Bitmap createReflectedImage(Bitmap originalImage) {

        final int reflectionGap = 4;

        int width = originalImage.getWidth();
        int height = originalImage.getHeight();

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

        Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 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(originalImage, 0, 0, null);

        Paint defaultPaint = new Paint();
        canvas.drawRect(0, height, width, height + reflectionGap, defaultPaint);

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

        Paint paint = new Paint();
        LinearGradient shader = new LinearGradient(0,
                originalImage.getHeight(), 0, bitmapWithReflection.getHeight()
                        + reflectionGap, 0x70ffffff, 0x00ffffff,
                TileMode.MIRROR);

        paint.setShader(shader);

        paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));

        canvas.drawRect(0, height, width, bitmapWithReflection.getHeight()
                + reflectionGap, paint);

        return bitmapWithReflection;
    }
}