Android 图片特效处理的方法实例

1. 图片放缩

// zoom 放缩 
public static bitmap zoombitmap(bitmap bitmap, int w, int h) { 
    int width = bitmap.getwidth(); 
    int height = bitmap.getheight(); 
    matrix matrix = new matrix(); 

    float scalewidth = w / (float) width; 
    float scaleheight = h / (float) height; 
    matrix.postscale(scalewidth, scaleheight); 

    bitmap bitmap2 = bitmap.createbitmap(bitmap, 0, 0, width, height, 
            matrix, true); 
    return bitmap2; 
} 

2. 获得圆角图片

// round corner bitmap 获得圆角图片 
public static bitmap getroundcornerbitmap(bitmap bitmap, float roundpx /*圆角的半径*/) { 
    int width = bitmap.getwidth(); 
    int height = bitmap.getheight(); 

    bitmap bitmap2 = bitmap.createbitmap(width, height, config.argb_8888); 
    canvas canvas = new canvas(bitmap2); 

    final int color = 0xff424242; 
    final paint paint = new paint(); 
    final rect rect = new rect(0, 0, width, height); 
    final rectf rectf = new rectf(rect); 

    paint.setcolor(color); 
    paint.setantialias(true); 
    canvas.drawargb(0, 0, 0, 0); 
    canvas.drawroundrect(rectf, roundpx, roundpx, paint); 

    paint.setxfermode(new porterduffxfermode(mode.src_in)); 
    canvas.drawbitmap(bitmap, rect, rect, paint); 

    return bitmap2; 
} 

3. 获得带倒影的图片

// reflect bitmap 获得带倒影的图片 
public static bitmap createreflectedbitmap(bitmap bitmap) { 
    //倒影和图片本身的间距 
    final int reflectedgap = 4; 
    int width = bitmap.getwidth(); 
    int height = bitmap.getheight(); 

    matrix matrix = new matrix(); 
    matrix.prescale(1, -1); 

    bitmap reflectedimage = bitmap.createbitmap(bitmap, 0, height / 2, 
            width, height / 2, matrix, false); 
    bitmap reflectedbitmap = bitmap.createbitmap(width, 
            (height + height / 2), config.argb_8888); 

    canvas canvas = new canvas(reflectedbitmap); 
    canvas.drawbitmap(bitmap, 0, 0, null); 
    paint defaultpaint = new paint(); 
    canvas.drawrect(0, height, width, height + reflectedgap, defaultpaint); 
    canvas.drawbitmap(reflectedimage, 0, height + reflectedgap, null); 

    paint paint = new paint(); 
    lineargradient shader = new lineargradient(0, bitmap.getheight(), 0, 
            reflectedbitmap.getheight() + reflectedgap, 0x70ffffff, 
            0x00ffffff, tilemode.clamp); 
    paint.setshader(shader); 
    paint.setxfermode(new porterduffxfermode(mode.dst_in)); 
    canvas.drawrect(0, height, width, reflectedbitmap.getheight() 
            + reflectedgap, paint); 

    return reflectedbitmap; 
}