Android中几种图像特效处理的集锦

大家好，这一节给大家分享的是Android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，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：

[代码]java代码:

001packagecom.android.tutor;

002   

003importandroid.graphics.Bitmap;

004importandroid.graphics.Canvas;

005importandroid.graphics.LinearGradient;

006importandroid.graphics.Matrix;

007importandroid.graphics.Paint;

008importandroid.graphics.PixelFormat;

009importandroid.graphics.PorterDuffXfermode;

010importandroid.graphics.Rect;

011importandroid.graphics.RectF;

012importandroid.graphics.Bitmap.Config;

013importandroid.graphics.PorterDuff.Mode;

014importandroid.graphics.Shader.TileMode;

015importandroid.graphics.drawable.Drawable;

016   

017publicclassImageUtil {

018   

019    // 放大缩小图片

020    publicstaticBitmap zoomBitmap(Bitmap bitmap,intw, inth) {

021        intwidth = bitmap.getWidth();

022        intheight = bitmap.getHeight();

023        Matrix matrix =newMatrix();

024        floatscaleWidht = ((float) w / width);

025        floatscaleHeight = ((float) h / height);

026        matrix.postScale(scaleWidht, scaleHeight);

027        Bitmap newbmp = Bitmap.createBitmap(bitmap,0,0, width, height,

028                matrix,true);

029        returnnewbmp;

030    }

031   

032    // 将Drawable转化为Bitmap

033    publicstaticBitmap drawableToBitmap(Drawable drawable) {

034        intwidth = drawable.getIntrinsicWidth();

035        intheight = drawable.getIntrinsicHeight();

036        Bitmap bitmap = Bitmap.createBitmap(width, height, drawable

037                .getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888

038                : Bitmap.Config.RGB_565);

039        Canvas canvas =newCanvas(bitmap);

040        drawable.setBounds(0,0, width, height);

041        drawable.draw(canvas);

042        returnbitmap;

043   

044    }

045   

046    // 获得圆角图片的方法

047    publicstaticBitmap getRoundedCornerBitmap(Bitmap bitmap,floatroundPx) {

048   

049        Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),

050                bitmap.getHeight(), Config.ARGB_8888);

051        Canvas canvas =newCanvas(output);

052   

053        finalintcolor = 0xff424242;

054        finalPaint paint =newPaint();

055        finalRect rect =newRect(0,0, bitmap.getWidth(), bitmap.getHeight());

056        finalRectF rectF =newRectF(rect);

057   

058        paint.setAntiAlias(true);

059        canvas.drawARGB(0,0,0,0);

060        paint.setColor(color);

061        canvas.drawRoundRect(rectF, roundPx, roundPx, paint);

062   

063        paint.setXfermode(newPorterDuffXfermode(Mode.SRC_IN));

064        canvas.drawBitmap(bitmap, rect, rect, paint);

065   

066        returnoutput;

067    }

068   

069    // 获得带倒影的图片方法

070    publicstaticBitmap createReflectionImageWithOrigin(Bitmap bitmap) {

071        finalintreflectionGap = 4;

072        intwidth = bitmap.getWidth();

073        intheight = bitmap.getHeight();

074   

075        Matrix matrix =newMatrix();

076        matrix.preScale(1, -1);

077   

078        Bitmap reflectionImage = Bitmap.createBitmap(bitmap,0, height /2,

079                width, height /2, matrix,false);

080   

081        Bitmap bitmapWithReflection = Bitmap.createBitmap(width,

082                (height + height /2), Config.ARGB_8888);

083   

084        Canvas canvas =newCanvas(bitmapWithReflection);

085        canvas.drawBitmap(bitmap,0,0,null);

086        Paint deafalutPaint =newPaint();

087        canvas.drawRect(0, height, width, height + reflectionGap, deafalutPaint);

088   

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

090   

091        Paint paint =newPaint();

092        LinearGradient shader =newLinearGradient(0, bitmap.getHeight(),0,

093                bitmapWithReflection.getHeight() + reflectionGap,0x70ffffff,

094                0x00ffffff, TileMode.CLAMP);

095        paint.setShader(shader);

096        // Set the Transfer mode to be porter duff and destination in

097        paint.setXfermode(newPorterDuffXfermode(Mode.DST_IN));

098        // Draw a rectangle using the paint with our linear gradient

099        canvas.drawRect(0, height, width, bitmapWithReflection.getHeight()

100                + reflectionGap, paint);

101   

102        returnbitmapWithReflection;

103    }

104   

105}

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

[代码]xml代码：

01<?xmlversion="1.0"encoding="utf-8"?>

02<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"

03    android:orientation="vertical"

04    android:layout_width="fill_parent"

05    android:layout_height="fill_parent"

06    >

07    <ImageView

08        android:id="@+id/image01"

09        android:layout_width="wrap_content"

10        android:layout_height="wrap_content"

11        android:padding="10px"

12        />

13    <ImageView

14        android:id="@+id/image02"

15        android:layout_width="wrap_content"

16        android:layout_height="wrap_content"

17        android:padding="10px"

18    />

19</LinearLayout>

第四步：修改主核心程序，ImageDemo.java,代码如下：

[代码]java代码：

01packagecom.android.tutor;

02   

03importandroid.app.Activity;

04importandroid.graphics.Bitmap;

05importandroid.graphics.drawable.Drawable;

06importandroid.os.Bundle;

07importandroid.widget.ImageView;

08   

09publicclassImagedemo extendsActivity {

10       

11    privateImageView mImageView01, mImageView02;

12   

13    publicvoidonCreate(Bundle savedInstanceState) {

14        super.onCreate(savedInstanceState);

15        setContentView(R.layout.main);

16        setupViews();

17    }

18   

19    privatevoidsetupViews() {

20           

21        mImageView01 = (ImageView) findViewById(R.id.image01);

22        mImageView02 = (ImageView) findViewById(R.id.image02);

23   

24        // 获取壁纸返回值是Drawable

25        Drawable drawable = getWallpaper();

26        // 将Drawable转化为Bitmap

27        Bitmap bitmap = ImageUtil.drawableToBitmap(drawable);

28        // 缩放图片

29        Bitmap zoomBitmap = ImageUtil.zoomBitmap(bitmap,100,100);

30        // 获取圆角图片

31        Bitmap roundBitmap = ImageUtil

32                .getRoundedCornerBitmap(zoomBitmap,10.0f);

33        // 获取倒影图片

34        Bitmap reflectBitmap = ImageUtil

35                .createReflectionImageWithOrigin(zoomBitmap);

36        // 这里可以让Bitmap再转化为Drawable

37        // Drawable roundDrawable = new BitmapDrawable(roundBitmap);

38        // Drawable reflectDrawable = new BitmapDrawable(reflectBitmap);

39        // mImageView01.setBackgroundDrawable(roundDrawable);

40        // mImageView02.setBackgroundDrawable(reflectDrawable);

41   

42        mImageView01.setImageBitmap(roundBitmap);

43        mImageView02.setImageBitmap(reflectBitmap);

44    }

45   

46}

第五步：运行上述工程，查看效果如下：

OK大功告成了!!