警报

用于呈现原生 iOS 警报对话框的 SwiftUI 警报组件。

iOS

tvOS

Included in Expo Go

Recommended version:

~57.0.3

Expo UI Alert 与官方 SwiftUI alert API 相匹配，并呈现带有标题、操作和可选消息的原生 iOS 警报对话框。

Alert asking the user to confirm signing out

Alert 是 ConfirmationDialog 的居中模态对应组件，后者会从屏幕底部呈现为操作表单。两者共享相同的触发器/操作/信息插槽模型，因此调用者可以通过更改组件名称在它们之间切换。

安装

🌐 Installation

Terminal

- npx expo install @expo/ui

If you are installing this in an existing React Native app, make sure to install expo in your project.

用法

🌐 Usage

基本警报

🌐 Basic alert

使用 Alert.Trigger 来定义可见元素，使用 Alert.Actions 来提供对话框按钮。

🌐 Use Alert.Trigger to define the visible element and Alert.Actions to provide the dialog buttons.

BasicAlertExample.tsx

import { useState } from 'react';
import { Host, Alert, Button } from '@expo/ui/swift-ui';

export default function BasicAlertExample() {
  const [isPresented, setIsPresented] = useState(false);

  return (
    <Host matchContents>
      <Alert title="已保存" isPresented={isPresented} onIsPresentedChange={setIsPresented}>
        <Alert.Trigger>
          <Button label="Show alert" onPress={() => setIsPresented(true)} />
        </Alert.Trigger>
        <Alert.Actions>
          <Button label="OK" onPress={() => setIsPresented(false)} />
        </Alert.Actions>
      </Alert>
    </Host>
  );
}

取消并确认

🌐 Cancel and confirm

将 role="cancel" 与确认按钮结合以构建标准的是/否警告。

🌐 Combine role="cancel" with a confirm button to build a standard yes/no alert.

CancelConfirmAlertExample.tsx

import { useState } from 'react';
import { Host, Alert, Button, Text } from '@expo/ui/swift-ui';

export default function CancelConfirmAlertExample() {
  const [isPresented, setIsPresented] = useState(false);

  return (
    <Host matchContents>
      <Alert title="注销吗？" isPresented={isPresented} onIsPresentedChange={setIsPresented}>
        <Alert.Trigger>
          <Button label="Sign out" onPress={() => setIsPresented(true)} />
        </Alert.Trigger>
        <Alert.Actions>
          <Button label="Sign Out" onPress={() => console.log('Signed out')} />
          <Button label="Cancel" role="cancel" />
        </Alert.Actions>
        <Alert.Message>
          <Text>You will need to sign in again to access your account.</Text>
        </Alert.Message>
      </Alert>
    </Host>
  );
}

破坏性行为

🌐 Destructive action

在 Alert.Actions 内的 Button 上使用 role="destructive" 来将其样式设置为破坏性操作。

🌐 Use role="destructive" on a Button inside Alert.Actions to style it as a destructive action.

DestructiveAlertExample.tsx

import { useState } from 'react';
import { Host, Alert, Button, Text } from '@expo/ui/swift-ui';

export default function DestructiveAlertExample() {
  const [isPresented, setIsPresented] = useState(false);

  return (
    <Host matchContents>
      <Alert title="删除账户？" isPresented={isPresented} onIsPresentedChange={setIsPresented}>
        <Alert.Trigger>
          <Button label="Delete account" role="destructive" onPress={() => setIsPresented(true)} />
        </Alert.Trigger>
        <Alert.Actions>
          <Button
            label="Delete"
            role="destructive"
            onPress={() => {
              console.log('Deleted');
              setIsPresented(false);
            }}
          />
          <Button label="Cancel" role="cancel" />
        </Alert.Actions>
        <Alert.Message>
          <Text>This permanently deletes your account and all data. This cannot be undone.</Text>
        </Alert.Message>
      </Alert>
    </Host>
  );
}

应用接口

🌐 API

import { Alert } from '@expo/ui/swift-ui';

Component

`Alert`

Type: React.Element<AlertProps>

Alert presents a SwiftUI alert with a title, optional message, and action buttons.

See: Official SwiftUI documentation.

Props of the Alert component.

AlertProps

`children`

Type: React.ReactNode

The contents of the alert. Should include Alert.Trigger, Alert.Actions, and optionally Alert.Message.

`isPresented`

Optional • Type: boolean

Whether the alert is presented.

`onIsPresentedChange`

Optional • Type: (isPresented: boolean) => void

A callback that is called when the isPresented state changes.

`title`

Type: string

The title of the alert.

Inherited Props

CommonViewModifierProps