Android给任何view添加全屏倾斜水印

 public static Bitmap getMarkTextBitmap(Context gContext, String gText, int width, int height, boolean is4Showing){//  Bitmap bitmap = ACache.get(gContext).getAsBitmap(gText);//  if (is4Showing && bitmap != null){//   return bitmap;//  }  float textSize;  float inter;  if (is4Showing){   textSize = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, 18, gContext.getResources().getDisplayMetrics());   inter = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 25, gContext.getResources().getDisplayMetrics());  } else {   textSize = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, 54, gContext.getResources().getDisplayMetrics());   inter = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 75, gContext.getResources().getDisplayMetrics());  }  int sideLength;  if (width > height) {   sideLength = (int) Math.sqrt(2*(width * width));  } else {   sideLength = (int) Math.sqrt(2*(height * height));  }  Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);  Rect rect = new Rect();  paint.setTextSize(textSize);  //获取文字长度和宽度  paint.getTextBounds(gText, 0, gText.length(), rect);  int strwid = rect.width();  int strhei = rect.height();  Bitmap markBitmap = null;  try {   markBitmap = Bitmap.createBitmap(sideLength, sideLength, Bitmap.Config.ARGB_4444);   Canvas canvas = new Canvas(markBitmap);   //创建透明画布   canvas.drawColor(Color.TRANSPARENT);   paint.setColor(Color.BLACK);   paint.setAlpha((int) (0.1*255f));   // 获取跟清晰的图像采样   paint.setDither(true);   paint.setFilterBitmap(true);   //先平移，再旋转才不会有空白，使整个图片充满   if (width > height) {    canvas.translate(width - sideLength - inter, sideLength - width + inter);   } else {    canvas.translate(height - sideLength - inter, sideLength - height + inter);   }   //将该文字图片逆时针方向倾斜45度   canvas.rotate(-45);   for (int i =0; i <= sideLength; ){    int count = 0;    for (int j =0; j <= sideLength; count++){     if (count % 2 == 0){      canvas.drawText(gText, i, j, paint);     } else {      //偶数行进行错开      canvas.drawText(gText, i + strwid/2, j, paint);     }     j = (int) (j + inter + strhei);    }    i = (int) (i + strwid + inter);   }   canvas.save(Canvas.ALL_SAVE_FLAG);//  ACache.get(gContext).put(gText, markBitmap);  } catch (OutOfMemoryError e) {   Util.LOGD(TAG, e);   if(markBitmap != null && !markBitmap.isRecycled()){    markBitmap.recycle();    markBitmap = null;   }  }  return markBitmap; }

 /**  * 获得文字水印的图片  * @param width  * @param height  * @return  */ public static Drawable getMarkTextBitmapDrawable(Context gContext, String gText, int width, int height, boolean is4Showing){  Bitmap bitmap = getMarkTextBitmap(gContext, gText, width, height, is4Showing);  if (bitmap != null){   BitmapDrawable drawable = new BitmapDrawable(gContext.getResources(), bitmap);   drawable.setTileModeXY(Shader.TileMode.REPEAT, Shader.TileMode.REPEAT);   drawable.setDither(true);//   Drawable drawableFinal = drawable.getConstantState().newDrawable();//   if(!bitmap.isRecycled()){//    bitmap.recycle();//    bitmap = null;//   }//   return drawable;  }  return null; }