转：Android中几种图像特效处理方法小结

原文地址：http://www.androidmi.com/Androidkaifa/jinjie/201011/1788.html

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大家好,这一节给大家分享的是Android中几种图像特效处理的小技巧,比如圆角,倒影,还有就是图片缩放,Drawable转化为Bitmap,Bitmap转化为Drawable等等.

废话少说了,直接讲解今天的实例,本例主要是先获取壁纸(getWallpaper()),然后对当前壁纸的一些特效处理.大家按步骤一步一步来:

第一步:新建一个Android工程命名为ImageDemo,工程结构如下:

第二步:新建一个.java文件,命名为ImageUtil.java,在里面定义一些图片处理方法,代码如下:

 

package com.android.tutor;   
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   
    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   
     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   
    public static Bitmap createReflectionImageWithOrigin(Bitmap bitmap){   
        final int reflectionGap = 4;   
        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 bitmapWithReflection = Bitmap.createBitmap(width, (height + height/2), Config.ARGB_8888);   
           
        Canvas canvas = new Canvas(bitmapWithReflection);   
        canvas.drawBitmap(bitmap, 0, 0, null);   
        Paint deafalutPaint = new Paint();   
        canvas.drawRect(0, height,width,height + reflectionGap,   
                deafalutPaint);   
           
        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);   
        // 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   
        canvas.drawRect(0, height, width, bitmapWithReflection.getHeight()   
                + reflectionGap, paint);   
    
        return bitmapWithReflection;   
    }   
       
} 

 

 

 

第三步:修改main.xml布局文件,主要放了两个ImageView控件,代码如下:

 

<?xml version="1.0" encoding="utf-8"?>   
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  
    android:orientation="vertical"  
    android:layout_width="fill_parent"  
    android:layout_height="fill_parent"  
    >   
    <ImageView    
        android:id="@+id/image01"    
        android:layout_width="wrap_content"    
        android:layout_height="wrap_content"    
        android:padding="10px"  
        />   
    <ImageView   
        android:id="@+id/image02"  
        android:layout_width="wrap_content"    
        android:layout_height="wrap_content"    
        android:padding="10px"  
    />   
</LinearLayout>  
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
 <ImageView 
  android:id="@+id/image01" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:padding="10px"
     />
 <ImageView
  android:id="@+id/image02"
  android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:padding="10px"
 />
</LinearLayout>

 

第四步:修改主核心程序,ImageDemo.java,代码如下:

 

package com.android.tutor;   
import android.app.Activity;   
import android.graphics.Bitmap;   
import android.graphics.drawable.Drawable;   
import android.os.Bundle;   
import android.widget.ImageView;   
public class Imagedemo extends Activity {   
    private ImageView mImageView01,mImageView02;   
       
    public void onCreate(Bundle savedInstanceState) {   
        super.onCreate(savedInstanceState);   
        setContentView(R.layout.main);   
        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, 100, 100);   
        //获取圆角图片   
        Bitmap roundBitmap = ImageUtil.getRoundedCornerBitmap(zoomBitmap, 10.0f);   
        //获取倒影图片   
        Bitmap reflectBitmap = ImageUtil.createReflectionImageWithOrigin(zoomBitmap);   
        //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);   
    }   
}  

 

第五步:运行上述工程,查看效果如下:

OK大功告成了!!