I'm developing an applicaiton using Android 11 and Kotlin. I've successfully written a file to the Download folder on the device. When writing to the folder again using the same file name, the result is another file with the same name. So now I have two files with the same name.

So first I thought I'd just delete the file then write it again. I spent hours and hours trying that to no avail. The delete code would execute without exception but the file would never delete. I'm pretty sure I set the proper permissions by using

  if (!isWriteExternalStoragePermissionGranted()) {
            val permissions = arrayOf(WRITE_EXTERNAL_STORAGE)
            for (i in permissions.indices) {
                requestPermission(permissions[i], i)
            }
        }


 private fun isWriteExternalStoragePermissionGranted(): Boolean {
        val permissionCheck = ActivityCompat.checkSelfPermission(this,  WRITE_EXTERNAL_STORAGE)
        return permissionCheck == PackageManager.PERMISSION_GRANTED
    }

Then I thought I'd truncate the contents of the file and just overwrite the files contents. That didn't work. Just annother copy of file again and again. I have spent almpost a full day on this. It really shouldn't be this hard. I've tried numerous examples.. nothing works. Here's my code to write the file...

 fun writeToFile(applicationContext: Context, filename: String, data: String) {

    try {
        val resolver = applicationContext.contentResolver
        val values = ContentValues()
        values.put(MediaStore.MediaColumns.DISPLAY_NAME, filename)
        values.put(MediaStore.MediaColumns.MIME_TYPE, "text/xml")
        values.put(MediaStore.MediaColumns.RELATIVE_PATH, Environment.DIRECTORY_DOWNLOADS)
        val uri = resolver.insert(MediaStore.Files.getContentUri("external"), values)

        //val cr: ContentResolver = getContentResolver()
        val os: OutputStream? = uri?.let { resolver.openOutputStream(it,"wt") }

        if (os != null) {
            os.write(data.toByteArray())
            os.flush()
            os.close()
        }
        /*
        if (uri != null) {
            resolver.openFileDescriptor(uri, "wt")?.use {
                FileOutputStream(it.fileDescriptor).use {
                     it.write(data.toByteArray()
                    )
                }
            }
        }
        */

        } catch (e: FileNotFoundException) {
            e.printStackTrace()
        } catch (e: IOException) {
            e.printStackTrace()
        }
}

Here's my code to delete the file first that never works. I've tried multiple variations...

fun deleteFile(context: Context, filename: String, applicationContext: Context){

    val myFile = File(context.getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS), filename)
    if (myFile.exists()) {
        myFile.delete()
    }
}


fun deleteFile(context: Context, filename: String, applicationContext: Context){

    val resolver = applicationContext.contentResolver
    val values = ContentValues()
    values.put(MediaStore.MediaColumns.DISPLAY_NAME, filename)
    values.put(MediaStore.MediaColumns.MIME_TYPE, "text/xml")
    values.put(MediaStore.MediaColumns.RELATIVE_PATH, Environment.DIRECTORY_DOWNLOADS)
    val uri = resolver.insert(MediaStore.Files.getContentUri("external"), values)

    if (uri != null) {
        resolver.delete(uri, null, null)
    }

}

CodePudding user response：

You should use the uri you got with the first insert() where you created the file.