Jetpack Compose 联系人选取器

Question

So... Yesterday my code was working just fine, but today, I don't know what happend it stoped working. The cursor is null and returns both "". I don't know what to do.

Is the cursor even working?

@SuppressLint("Range", "Recycle")
@Composable
fun ContactPickerTwinTurbo(
    done: (String, String) -> Unit
) {
    val context = LocalContext.current
    val launcher = rememberLauncherForActivityResult(
        contract = ActivityResultContracts.PickContact(),
        onResult = {
            val contentResolver: ContentResolver = context.contentResolver
            var name = ""
            var number = ""
            val cursor: Cursor? = contentResolver.query(it!!, null, null, null, null)
            if (cursor != null) {
                if (cursor.moveToFirst()) {
                    name =
                        cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME))
                    Log.d("Name", name)
                    val id = cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts._ID))
                    val phones: Cursor? = contentResolver.query(
                        Phone.CONTENT_URI, null,
                        Phone.CONTACT_ID + " = " + id, null, null
                    )
                    if (phones != null) {
                        while (phones.moveToNext()) {
                            number = phones.getString(phones.getColumnIndex(Phone.NUMBER))
                            Log.d("Number", number)
                        }
                        phones.close()
                    }
                }
            }
            done(name, number)
        }
    )
    Button(
        onClick = {
            launcher.launch()
        },
        modifier = Modifier
            .fillMaxWidth()
            .padding(10.dp)
    ) {
        Text(text = "Pick Contact")
    }
}

How does the cursor works? Do I have to wait? am I supposed to ask permission to access the contacts?

Answer 1

Apparently Yes you need to ask for permission in runtime to get access the contact. For References check this link [check link][1]https://www.geeksforgeeks.org/contact-picker-in-android-using-jetpack-compose/

Answer 2

Replace: var name = "" -> var name = remember{ mutableStateOf("") }
var number = "" -> var number = remember{ mutableStateOf("") }

and while accessing, use name.value and number.value