如何在 kotlin 中将位图转换为字符串，将字符串转换为位图

Question

I am trying to write the code I used to use in Java, but it does not seem to work in kotlin.

// in java

 public String BitMapToString(Bitmap bitmap){
     ByteArrayOutputStream baos=new  ByteArrayOutputStream();
     bitmap.compress(Bitmap.CompressFormat.PNG,100, baos);
     byte [] b=baos.toByteArray();
     String temp=Base64.encodeToString(b, Base64.DEFAULT);
     return temp;}

  // iam try like this
  // Base.encodeToString not work
  // that work is like this But request for Requires API O
  fun BitMapToString(bitmap: Bitmap): String {
     val base = ByteArrayOutputStream()
     bitmap.compress(Bitmap.CompressFormat.PNG, 100, base)
     val b = base.toByteArray()
     return Base64.getEncoder().encodeToString(b)
  }

how can I convert from bitmap to String in kotlin?

Answer 1

Just write this code:

fun BitMapToString(bitmap: Bitmap): String {
    val baos = ByteArrayOutputStream()
    bitmap.compress(Bitmap.CompressFormat.PNG, 100, baos)
    val b = baos.toByteArray()
    return Base64.encodeToString(b, Base64.DEFAULT)
}

Answer 2

That is all. You just have to decode the base 64 string first into a byte array.:

val imageBytes = Base64.decode(string, 0)
val image = BitmapFactory.decodeByteArray(imageBytes, 0, imageBytes.size)

Answer 3

I tried the code that showed as wrong and it worked that way

    @SuppressLint("NewApi")
    @TargetApi(Build.VERSION_CODES.O)
    @RequiresApi(Build.VERSION_CODES.O)
    fun BitMapToString(bitmap: Bitmap): String {
        val baos = ByteArrayOutputStream()
        bitmap.compress(Bitmap.CompressFormat.PNG, 100, baos)
        val b = baos.toByteArray()
        return Base64.getEncoder().encodeToString(b)
    }