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一:resources中获取Bitmap
- Resources res = getResources();
- Bitmap bmp = BitmapFactory.decodeResource(res, R.drawable.icon);
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二:Bitmap 转 byte[]格式
- public byte[] Bitmap2Bytes(Bitmap bm) {
- ByteArrayOutputStream baos = new ByteArrayOutputStream();
- bm.compress(Bitmap.CompressFormat.PNG, 100, baos);
- return baos.toByteArray();
- }
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三:byte[] 转 Bitmap格式
- public Bitmap Bytes2Bimap(byte[] b) {
- if (b.length != 0) {
- return BitmapFactory.decodeByteArray(b, 0, b.length);
- } else {
- return null;
- }
- }
复制代码 四:Bitmap缩放
- public static Bitmap zoomBitmap(Bitmap bitmap, int width, int height) {
- int w = bitmap.getWidth();
- int h = bitmap.getHeight();
- Matrix matrix = new Matrix();
- float scaleWidth = ((float) width / w);
- float scaleHeight = ((float) height / h);
- matrix.postScale(scaleWidth, scaleHeight);
- Bitmap newbmp = Bitmap.createBitmap(bitmap, 0, 0, w, h, matrix, true);
- return newbmp;
- }
复制代码 五:将Drawable转化为Bitmap
- public static Bitmap drawableToBitmap(Drawable drawable) {
- // 取 drawable 的长宽
- int w = drawable.getIntrinsicWidth();
- int h = drawable.getIntrinsicHeight();
- // 取 drawable 的颜色格式
- Bitmap.Config config = drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
- : Bitmap.Config.RGB_565;
- // 建立对应 bitmap
- Bitmap bitmap = Bitmap.createBitmap(w, h, config);
- // 建立对应 bitmap 的画布
- Canvas canvas = new Canvas(bitmap);
- drawable.setBounds(0, 0, w, h);
- // 把 drawable 内容画到画布中
- drawable.draw(canvas);
- return bitmap;
- }
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六:获得圆角图片
- public static Bitmap getRoundedCornerBitmap(Bitmap bitmap, float roundPx) {
- int w = bitmap.getWidth();
- int h = bitmap.getHeight();
- Bitmap output = Bitmap.createBitmap(w, h, Config.ARGB_8888);
- Canvas canvas = new Canvas(output);
- final int color = 0xff424242;
- final Paint paint = new Paint();
- final Rect rect = new Rect(0, 0, w, h);
- 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;
- }
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七:Bitmap转换成Drawable
- Bitmap bm=xxx; //xxx根据你的情况获取
- BitmapDrawable bd= new BitmapDrawable(getResource(), bm);
- //因为BtimapDrawable是Drawable的子类,最终直接使用bd对象即可。
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八:Drawable缩放
- public static Drawable zoomDrawable(Drawable drawable, int w, int h) {
- int width = drawable.getIntrinsicWidth();
- int height = drawable.getIntrinsicHeight();
- // drawable转换成bitmap
- Bitmap oldbmp = drawableToBitmap(drawable);
- // 创建操作图片用的Matrix对象
- Matrix matrix = new Matrix();
- // 计算缩放比例
- float sx = ((float) w / width);
- float sy = ((float) h / height);
- // 设置缩放比例
- matrix.postScale(sx, sy);
- // 建立新的bitmap,其内容是对原bitmap的缩放后的图
- Bitmap newbmp = Bitmap.createBitmap(oldbmp, 0, 0, width, height,matrix, true);
- return new BitmapDrawable(newbmp);
- }
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