分配不是表达式，并且在此上下文中仅允许表达式

Question

private fun copyDatabase(context: Context): Boolean {
    try {

        val inputStream = context.assets.open(DatabaseHelper.DBNAME)
        val outFileName = DatabaseHelper.DBLOCATION + DatabaseHelper.DBNAME
        val outputStream = FileOutputStream(outFileName)
        val buff = ByteArray(1024)
        var length = 0

        while((length = inputStream.read(buff)) > 0) {
            outputStream.write(buff , 0 , length)
        }

        outputStream.flush()
        outputStream.close()
        Log.w("MainActivity" , "DB copied")
        return true
    } catch (e: Exception) {
        e.printStackTrace()
        return false
    }

}

"while" in this code is not working i need help please

Answer 1

It looks like you're trying to copy the InputStream contents to an OutputStream. For this task you can use InputStream.copyTo extension function in Kotlin:

// instead of while loop
inputStream.copyTo(outputStream, bufferSize = 1024)

Answer 2

You can fix this like so:

    ...
    var length = inputStream.read(buff)

    while(length  > 0) {
        outputStream.write(buff , 0 , length)
        length = inputStream.read(buff)
    }
    ...  

but @Ilya is right, you are in Kotlin land and be better off using the tools Kotlin provides