Android 轻松实现图片倒影效果实例代码

package com.mj.myweather;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.widget.ImageView;
import com.mj.myweather.utils.ImageUtil;

public class ImageActivity extends Activity {

// 声明控件
private ImageView mImageView01, mImageView02;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.image);
setupViews();

}
private void setupViews() {
mImageView01 = (ImageView) findViewById(R.id.image01);
mImageView02 = (ImageView) findViewById(R.id.image02);
// 获取壁纸返回值是Drawable
Drawable drawable = getWallpaper();
// 将Drawable转化为Bitmap
Bitmap bitmap = ImageUtil.drawableToBitmap(drawable);
// 缩放图片
Bitmap zoomBitmap = ImageUtil.zoomBitmap(bitmap, 300, 300);
// 获取圆角图片
Bitmap roundBitmap = ImageUtil
.getRoundedCornerBitmap(zoomBitmap, 10.0f);
// 获取倒影图片
Bitmap reflectBitmap = ImageUtil
.createReflectionImageWithOrigin(roundBitmap);
// 这里可以让Bitmap再转化为Drawable
// Drawable roundDrawable = new BitmapDrawable(roundBitmap);
// Drawable reflectDrawable = new BitmapDrawable(reflectBitmap);
// mImageView01.setBackgroundDrawable(roundDrawable);
// mImageView02.setBackgroundDrawable(reflectDrawable);
mImageView01.setImageBitmap(roundBitmap);
mImageView02.setImageBitmap(reflectBitmap);
}
}

<?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" >

    <ImageView
        android:id="@+id/image01"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="10dp" />

    <ImageView
        android:id="@+id/image02"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="10dp" />

</LinearLayout>

package com.mj.myweather.utils;

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.LinearGradient;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.Bitmap.Config;
import android.graphics.PorterDuff.Mode;
import android.graphics.Shader.TileMode;
import android.graphics.drawable.Drawable;

public class ImageUtil {
/**
* 放大缩小图片
* @param bitmap
* @param w
* @param h
* @return
*/
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
* @param drawable
* @return
*/
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
* @param originalImage
* @return
*/
public static Bitmap createReflectionImageWithOrigin(Bitmap originalImage) {
final int reflectionGap = 4;
int width = originalImage.getWidth();
int height = originalImage.getHeight();
Matrix matrix = new Matrix();
// 图片矩阵变换（从低部向顶部的倒影）// 实现图片翻转90度
matrix.preScale(1, -1);
// 创建反转后的图片Bitmap对象，图片高是原图的一半
Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0, height / 2,
width, height / 2, matrix, false);
// 创建标准的Bitmap对象，宽和原图一致，高是原图的1.5倍
Bitmap bitmapWithReflection = Bitmap.createBitmap(width,
(height + height / 2), Config.ARGB_8888);
// 创建画布对象，将原图画于画布，起点是原点位置
Canvas canvas = new Canvas(bitmapWithReflection);
canvas.drawBitmap(originalImage, 0, 0, null);
// 将反转后的图片画到画布中
Paint deafalutPaint = new Paint();
canvas.drawRect(0, height, width, height + reflectionGap, deafalutPaint);
canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null);
Paint paint = new Paint();
// 创建线性渐变LinearGradient对象
LinearGradient shader = new LinearGradient(0, originalImage.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
// 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
canvas.drawRect(0, height, width, bitmapWithReflection.getHeight()
+ reflectionGap, paint);
return bitmapWithReflection;
}
}