Java byte數(shù)組轉(zhuǎn)hex

public String byteArrToHex(byte[] data){
  StringBuilder sb = new StringBuilder();
  for(byte b : data){
    sb.append(String.format("%02x", b&0xff));
  }
  return sb.toString();
}

重要代碼:String.format("%02x", b&0xff)

Jetpack Compose

和Flutter一樣擺脫了xml,通過代碼來實(shí)現(xiàn)界面
https://developer.android.google.cn/jetpack/compose/tutorial?hl=zh-cn
https://developer.android.com/jetpack/compose

Java 中Bitmap變?yōu)榛疑?/h2>

原因:最近做攝像頭相關(guān)的,再列表中當(dāng)設(shè)備離線之后變?yōu)榛疑?讓用戶看起來更加直觀明了

public Bitmap grey(Bitmap bitmap) {
        int width = bitmap.getWidth();
        int height = bitmap.getHeight();
        Bitmap faceIconGreyBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(faceIconGreyBitmap);
        Paint paint = new Paint();
        ColorMatrix colorMatrix = new ColorMatrix();
        colorMatrix.setSaturation(0);
        ColorMatrixColorFilter colorMatrixFilter = new ColorMatrixColorFilter(colorMatrix);
        paint.setColorFilter(colorMatrixFilter);
        canvas.drawBitmap(bitmap, 0, 0, paint);
        return faceIconGreyBitmap;
    }