Question

如何在jetpack撰写中自动关注文本字段。当我单击文本字段并开始在其上键入时。同时，当我单击“后退”按钮时，然后当我尝试单击文本字段时，什么也没有发生。

val textState = remember { mutableStateOf(TextFieldValue()) }
TextField(
    modifier = Modifier.fillMaxWidth(),
    value = textState.value,
    onValueChange = { value : TextFieldValue ->
        textState.value = value
    }
)

Answer 1

发布问题的更新答案（API 在 Compose Beta 中重命名）

@Composable
fun AutoFocusingText() {
    var value by mutableStateOf("Enter Text")
    val focusRequester = remember { FocusRequester() }
    TextField(
        value = value, 
        onValueChange = { value = it },
        modifier = Modifier.focusRequester(focusRequester)
    )
    
    DisposableEffect(Unit) {
        focusRequester.requestFocus()
        onDispose { }
    }
}

Answer 2

来自撰写单元测试，并应用于TextField Link

    @ExperimentalFocus
    @Composable
    fun AutoFocusingText() {
        val textState = remember { mutableStateOf(TextFieldValue()) }
        val focusState = remember { mutableStateOf(FocusState.Inactive) }
        val focusRequester = FocusRequester()
        val focusModifier = Modifier.focus()
        Row(
            modifier = Modifier.focusObserver { focusState.value = it }
        ) {
            val focusRequesterModifier = Modifier.focusRequester(focusRequester)
            TextField(
                modifier = focusModifier.then(focusRequesterModifier),
                value = textState.value,
                onValueChange = { value: TextFieldValue ->
                    textState.value = value
                },

                )
        }
        onActive {
            focusRequester.requestFocus()
        }
    }

编辑：由于Box已在'1.0.0-alpha04'中弃用，因此将Box更改为Row

Answer 3

使用 1.0.0-beta06，您可以使用以下内容：

var text by remember { mutableStateOf("text") }

// initialize focus reference to be able to request focus programmatically
val focusRequester = FocusRequester()

Column {
    TextField(
        value = text,
        onValueChange = {
            text = it
        },
        label = { Text("label") },
        modifier = Modifier
            // add focusRequester modifier 
            .focusRequester(focusRequester)
    )

然后使用 focusRequester.requestFocus()。通过这种方式，系统将焦点授予与此 FocusRequester 关联的组件。

要在屏幕出现时自动聚焦该字段，您可以使用：

DisposableEffect(Unit) {
    focusRequester.requestFocus()
    onDispose { }
}

手动将焦点授予该字段：

    Button(onClick = { focusRequester.requestFocus() }) {
        Text("Click to give the focus")
    }

在Jetpack中请求关注TextField撰写

3 个答案: