android 按比例缩放图片（适屏）
16lz
2021-01-23
private Bitmap reSize(Bitmap bitmaporg) { int widthold = bitmaporg.getWidth();//eg:1024 int heightold = bitmaporg.getHeight();//eg:819 //获取屏幕的宽高 DisplayMetrics dm = new DisplayMetrics(); getWindowManager().getDefaultDisplay().getMetrics(dm); int screenWidth = dm.widthPixels; //eg:1440 int screenHeigh = dm.heightPixels; //eg:2392 float density = dm.density; // 密度（0.75 / 1.0 / 1.5） //eg: 1dp=3.5px //int densityDpi = dm.densityDpi; // 密度DPI（120 / 160 / 240） float scale = (float) screenWidth / ((density + 0.2f) * widthold); Matrix matrix = new Matrix(); if (scale < 1) { //将大图缩小至适屏 float scaleWidth = (float) scale; float scaleHeight = (float) scale; matrix.postScale(scaleWidth, scaleHeight); } else { float scaleWidth = 1; float scaleHeight = 1; matrix.postScale(scaleWidth, scaleHeight); } Log.d("Main", "screenWidth:" + screenWidth); Log.d("Main", "screenHeight:" + screenHeigh); Log.d("Main", "widthold:" + widthold); Log.d("Main", "heightold:" + heightold); Bitmap bitmapnew = Bitmap.createBitmap(bitmaporg, 0, 0, widthold, heightold, matrix, true); int widtnew = bitmapnew.getWidth(); int heightnew = bitmapnew.getHeight(); Log.d("Main", "widthnew:" + widtnew); Log.d("Main", "heightnew:" + heightnew); return bitmapnew;}
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