ImageView倒影效果

ImageView倒影效果的两种方法 

第一种： 
写个图片的工具类，在Activity中用java代码调用ImageView组件的setImageBitmap(Bitmap bitmap)方法。 
下面是图片工具类：

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

public class ImageUtils {

    /** 
      * 从SDCard上读取图片 
      * @param pathName 
      * @return */
    public static Bitmap getBitmapFromSDCard(String pathName) {
        return BitmapFactory.decodeFile(pathName);
    }

    /** 
      * 缩放图片 
      * @param bitmap 
      * @param width 
      * @param height 
      * @return */
    public static Bitmap zoomBitmap(Bitmap bitmap, int width, int height) {
        int w = bitmap.getWidth();
        int h = bitmap.getHeight();
        Matrix matrix = new Matrix();
        matrix.postScale((float) width / w, (float) height / h);
        return Bitmap.createBitmap(bitmap, 0, 0, w, h, matrix, true);
    }

    /** 
      * 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 
      * @param bitmap 
      * @param roundPx 
      * @return 
      */
    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 Paint paint = new Paint();
        final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
        final RectF rectF = new RectF(rect);
        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 
      * @param bitmap 
      * @return 
      */
    public static Bitmap getReflectionImageWithOrigin(Bitmap bitmap) {
        
        // 原始图片和反射图片中间的间距
        final int reflectionGap = 0;
        int width = bitmap.getWidth();
        int height = bitmap.getHeight();
        
        // 反转  
        Matrix matrix = new Matrix();
        
        // 第一个参数为1表示x方向上以原比例为准保持不变，正数表示方向不变。   
        // 第二个参数为-1表示y方向上以原比例为准保持不变，负数表示方向取反。
        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 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, bitmap.getHeight(), 0,
                bitmapWithReflection.getHeight() + reflectionGap, 0x70ffffff,
                0x00ffffff, TileMode.CLAMP);
        paint.setShader(shader);
        paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
        canvas.drawRect(0, height, width, bitmapWithReflection.getHeight()
                + reflectionGap, paint);
        return bitmapWithReflection;
    }
}

 

 

在Activity中这样调用，先获取XML文件中定义的Imageview对象

image = (ImageView) findViewById(R.id.movie);

然后将获取到的Imageview对象转化为Bitmap类型

Bitmap imageBit = ((BitmapDrawable) image.getDrawable()).getBitmap();

接着调用图片工具类中的方法，返回一个Bitmap对象，将这个Bitmap对象放置在ImageView中

Bitmap m = ImageUtils.getReflectionImageWithOrigin(imageBit);
image.setImageBitmap(m);

第二种 
继承ImageView类 

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.LinearGradient;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PorterDuffXfermode;
import android.graphics.Bitmap.Config;
import android.graphics.PorterDuff.Mode;
import android.graphics.Shader.TileMode;
import android.graphics.drawable.BitmapDrawable;
import android.util.AttributeSet;
import android.widget.ImageView;

public class ReflectImageView extends ImageView {

    private Bitmap originalBitmap;

    public ReflectImageView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public ReflectImageView(Context context) {
        this(context, null, 0);
    }

    public ReflectImageView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        DoReflection(((BitmapDrawable) getDrawable()).getBitmap());
    }

    @Override
    public void setImageBitmap(Bitmap bm) {
        DoReflection(bm);

    }

    /** 显示倒影效果的setImageBitmap函数 */
    public void setImageBitmap(Bitmap bm, boolean isFlected) {
        if (isFlected) {
            super.setImageBitmap(bm);
        }
    }

    @Override
    public void setImageResource(int resId) {

        originalBitmap = BitmapFactory.decodeResource(getResources(), resId);
        DoReflection(originalBitmap);
    }

    private void DoReflection(Bitmap bitmap) {
        final int reflectionGap = 0;
        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 bitmap4Reflection = Bitmap.createBitmap(width,
                (height + height / 2), Config.ARGB_8888);
        Canvas canvasRef = new Canvas(bitmap4Reflection);
        Paint deafaultPaint = new Paint();
        deafaultPaint.setAntiAlias(true);
        canvasRef.drawBitmap(bitmap, 0, 0, null);
        canvasRef.drawRect(0, height, width, height + reflectionGap,
                deafaultPaint);
        canvasRef.drawBitmap(reflectionImage, 0, height + reflectionGap, null);
        Paint paint = new Paint();
        LinearGradient shader = new LinearGradient(0, bitmap.getHeight(), 0,
                bitmap4Reflection.getHeight() + reflectionGap, 0x70ffffff,
                0x00ffffff, TileMode.CLAMP);
        paint.setShader(shader);
        paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
        canvasRef.drawRect(0, height, width, bitmap4Reflection.getHeight()
                + reflectionGap, paint);
        this.setImageBitmap(bitmap4Reflection, true);
    }

}

然后在xml文件里面配置 

<com.hello.ReflectImageView
        android:id="@+id/imageView3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@+drawable/button1" />

转载：http://lws0402.iteye.com/blog/1397793