android 中实现图片倒影效果

1、效果图：

2、核心代码：

package com.example.pic_reflection;

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 {
    private ImageView img = null;
    private ImageView orginalImg;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        this.orginalImg = (ImageView) this.findViewById(R.id.img);
        this.orginalImg.setBackgroundResource(R.drawable.b);
        this.img = (ImageView) this.findViewById(R.id.reflection1);

        this.img.setImageBitmap(createReflectedImage(((BitmapDrawable) this.getResources().getDrawable(R.drawable.b)).getBitmap(), 110));
    }

    public static Bitmap createReflectedImage(Bitmap originalImage, int reflectionHeight) {
        int width = originalImage.getWidth();
        int height = originalImage.getHeight();
        Matrix matrix = new Matrix();
        // 实现图片翻转90度
        matrix.preScale(1, -1);
        if (reflectionHeight > height)
            reflectionHeight = height;
        // 创建倒影图片（是原始图片的一半大小）
        Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0, height - reflectionHeight, width, reflectionHeight, matrix, false);
        // 创建倒影图片
        Bitmap finalReflection = Bitmap.createBitmap(width, reflectionHeight, Config.ARGB_8888);
        // 创建画布
        Canvas canvas = new Canvas(finalReflection);
        // canvas.drawBitmap(originalImage, 0, 0, null);
        // 把倒影图片画到画布上
        canvas.drawBitmap(reflectionImage, 0, 0, null);
        Paint shaderPaint = new Paint();
        // 创建线性渐变LinearGradient对象
        LinearGradient shader = new LinearGradient(0, 0, 0, finalReflection.getHeight() + 1, 0x70ffffff, 0x00ffffff, TileMode.MIRROR);
        shaderPaint.setShader(shader);
        shaderPaint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
        // 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, 0, width, finalReflection.getHeight(), shaderPaint);
        return finalReflection;
    }

}

3、main.xml

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

    <include layout="@layout/activity_main" />

    <ImageView
        android:id="@+id/reflection1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

4、activity_main.xml

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

    <ImageView
        android:id="@+id/img"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scaleType="fitXY" />

    <TextView
        android:id="@+id/lblBanner"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"
        android:background="#88000000"
        android:ellipsize="end"
        android:gravity="center_horizontal|center_vertical"
        android:singleLine="true"
        android:text="小汽车一枚"
        android:textColor="#FFF" />

</FrameLayout>

android 中实现图片倒影效果,码迷,mamicode.com