Android--图片剪裁

调用系统Intent剪裁图片

 /**
      * 调用系统Intent剪裁图片
      * @param context
      * @param uri
      * @param w
      * @param h
      */
     public static void startPhotoZoom(Activity context,Uri uri, int w,int h) {
         
         Intent intent = new Intent("com.android.camera.action.CROP");
         intent.setDataAndType(uri, "image/*");
         // crop为true是设置在开启的intent中设置显示的view可以剪裁
         intent.putExtra("crop", "true");
         
         // aspectX aspectY 是宽高的比例
         intent.putExtra("aspectX", w);
         intent.putExtra("aspectY", h);
         
         // outputX,outputY 是剪裁图片的宽高
         intent.putExtra("outputX", w);
         intent.putExtra("outputY", h);
         intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(new File(fileName)));
         intent.putExtra("return-data", false);//若为false则表示不返回数据
         context.startActivityForResult(intent, PHOTO_REQUEST_CUT);
     }

  /**
     * 按正方形裁切图片
     */
    public static Bitmap ImageCrop(Bitmap bitmap) {
        if(bitmap == null)
            return null;
        int w = bitmap.getWidth(); // 得到图片的宽，高
        int h = bitmap.getHeight();

        int wh = w > h ? h : w;// 裁切后所取的正方形区域边长

        int retX = w > h ? (w - h) / 2 : 0;//基于原图，取正方形左上角x坐标
        int retY = w > h ? 0 : (h - w) / 2;

        //下面这句是关键
        Bitmap bit = Bitmap.createBitmap(bitmap, retX, retY, wh, wh, null, false);
        return bit;
    }

/**
     * 转换图片成圆形
     * 
     * @param bitmap
     *            传入Bitmap对象
     * @return
     */
    public static Bitmap toRoundBitmap(Bitmap bitmap) {
        int width = bitmap.getWidth();
        int height = bitmap.getHeight();
        float roundPx;
        float left, top, right, bottom, dst_left, dst_top, dst_right, dst_bottom;
        if (width <= height) {
            roundPx = width / 2;
            top = 0;
            bottom = width;
            left = 0;
            right = width;
            height = width;
            dst_left = 0;
            dst_top = 0;
            dst_right = width;
            dst_bottom = width;
        } else {
            roundPx = height / 2;
            float clip = (width - height) / 2;
            left = clip;
            right = width - clip;
            top = 0;
            bottom = height;
            width = height;
            dst_left = 0;
            dst_top = 0;
            dst_right = height;
            dst_bottom = height;
        }

        Bitmap output = Bitmap.createBitmap(width, height, Config.ARGB_8888);
        Canvas canvas = new Canvas(output);

        final int color = 0xff424242;
        final Paint paint = new Paint();
        final Rect src = new Rect((int) left, (int) top, (int) right,
                (int) bottom);
        final Rect dst = new Rect((int) dst_left, (int) dst_top,
                (int) dst_right, (int) dst_bottom);
        final RectF rectF = new RectF(dst);

        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, src, dst, paint);
        return output;
    }