试图在这里解决此问题，但我不知道是什么原因引起的...
我在项目中使用日历组件没有问题。但是，我认为用DatePicker替换它会更方便，后者显然使用了几乎相同的方法。这是我到目前为止的代码（相关部分）：
import React from 'react';
import {
Alert,
ScrollView,
StyleSheet,
View,
InteractionManager,
Image,
TextInput,
TouchableOpacity,
BackHandler
} from 'react-native';
import {
Card,
CardHeader,
Layout,
Text,
Calendar,
DatePicker,
Spinner,
} from '@ui-kitten/components';
import { TaskCard } from './components/task-card';
import { validate } from 'validate.js';
import { Auth, Storage, API, graphqlOperation, scTracker } from '../modules/commons';
import Styles from '../modules/styles';
import constraints from './fields/constraints';
import Ionicons from 'react-native-vector-icons/Ionicons';
import { CustomCalendar } from './components/custom-calendar';
class TasksScreen extends React.Component {
static navigationOptions = {
title: "Atividades",
};
state = {
cDate: null,
showCalendar: false,
};
constructor(props) {
super(props);
};
componentDidMount() {
try {
let lcDate = new Date();
this.setState({
cDate: lcDate,
});
} catch (e) {
console.log(e);
};
};
render() {
return(
. . . . .
<Layout level="2" style={{width:"100%"}}>
<DatePicker date={this.state.cDate}
onSelect={(date)=>{this.setState({cDate: date})}}
/>
</Layout>
<ScrollView contentContainerStyle={Styles.vScrollViewContent}>
<TaskCard
. . . . . .
但是由于某些原因，使用完全相同的参数，它开始触发一个错误，该错误指向包装日期选择器的Layout行（与所有其他Layout对象类似）：
Warning: React.createElement: type is invalid -- expected a string (for built-in components) or a class/function (for composite components) but got: %s.%s%s, undefined, You likely forgot to export your component from the file it's defined in, or you might have mixed up default and named imports.
Check your code at tasks-scr.js:91.,
in TasksScreen (at SceneView.js:9)
in SceneView (at createTabNavigator.tsx:67)
in RCTView (at View.js:45)
in View (at SceneView.tsx:92)
in SceneView (at TabView.tsx:173)
in RCTView (at View.js:45)
in View (at createAnimatedComponent.js:217)
in AnimatedComponent (at Pager.tsx:667)
in PanGestureHandler (at Pager.tsx:659)
in Pager (at TabView.tsx:70)
in RCTView (at View.js:45)
in View (at TabView.tsx:128)
in TabView (at createMaterialTopTabNavigator.tsx:136)
in MaterialTabView (at createTabNavigator.tsx:228)
in NavigationView (at createNavigator.js:80)
in Navigator (at SceneView.js:9)
in SceneView (at StackViewLayout.tsx:889)
in RCTView (at View.js:45)
in View (at StackViewLayout.tsx:888)
in RCTView (at View.js:45)
in View (at StackViewLayout.tsx:887)
in RCTView (at View.js:45)
in View (at createAnimatedComponent.js:151)
in AnimatedComponent (at StackViewCard.tsx:106)
in RCTView (at View.js:45)
in View (at createAnimatedComponent.js:151)
in AnimatedComponent (at screens.native.js:71)
in Screen (at StackViewCard.tsx:93)
in Card (at createPointerEventsContainer.tsx:95)
in Container (at StackViewLayout.tsx:975)
in RCTView (at View.js:45)
in View (at screens.native.js:101)
in ScreenContainer (at StackViewLayout.tsx:384)
in RCTView (at View.js:45)
in View (at createAnimatedComponent.js:151)
in AnimatedComponent (at StackViewLayout.tsx:374)
in PanGestureHandler (at StackViewLayout.tsx:367)
in StackViewLayout (at withOrientation.js:30)
in withOrientation (at StackView.tsx:104)
in RCTView (at View.js:45)
in View (at Transitioner.tsx:267)
in Transitioner (at StackView.tsx:41)
in StackView (at createNavigator.js:80)
in Navigator (at createKeyboardAwareNavigator.js:12)
in KeyboardAwareNavigator (at SceneView.js:9)
in SceneView (at StackViewLayout.tsx:889)
in RCTView (at View.js:45)
in View (at StackViewLayout.tsx:888)
in RCTView (at View.js:45)
in View (at StackViewLayout.tsx:887)
in RCTView (at View.js:45)
in View (at createAnimatedComponent.js:151)
in AnimatedComponent (at StackViewCard.tsx:106)
in RCTView (at View.js:45)
in View (at createAnimatedComponent.js:151)
in AnimatedComponent (at screens.native.js:71)
in Screen (at StackViewCard.tsx:93)
in Card (at createPointerEventsContainer.tsx:95)
in Container (at StackViewLayout.tsx:975)
in RCTView (at View.js:45)
in View (at screens.native.js:101)
in ScreenContainer (at StackViewLayout.tsx:384)
in RCTView (at View.js:45)
in View (at createAnimatedComponent.js:151)
in AnimatedComponent (at StackViewLayout.tsx:374)
in PanGestureHandler (at StackViewLayout.tsx:367)
in StackViewLayout (at withOrientation.js:30)
in withOrientation (at StackView.tsx:104)
in RCTView (at View.js:45)
in View (at Transitioner.tsx:267)
in Transitioner (at StackView.tsx:41)
in StackView (at createNavigator.js:80)
in Navigator (at createKeyboardAwareNavigator.js:12)
in KeyboardAwareNavigator (at createAppContainer.js:430)
in NavigationContainer (at App.js:21)
in RCTView (at View.js:45)
in View (at modalPanel.component.js:62)
in ModalPanel (at applicationProvider.component.js:68)
in ThemeProvider (at styleProvider.component.js:13)
in MappingProvider (at styleProvider.component.js:12)
in StyleProvider (at applicationProvider.component.js:67)
in ApplicationProvider (at App.js:19)
in App (at withExpoRoot.js:20)
in RootErrorBoundary (at withExpoRoot.js:19)
in ExpoRootComponent (at renderApplication.js:35)
in RCTView (at View.js:45)
in View (at AppContainer.js:98)
in RCTView (at View.js:45)
in View (at AppContainer.js:115)
in AppContainer (at renderApplication.js:34)
- node_modules/expo/build/environment/muteWarnings.fx.js:27:24 in error
- node_modules/react/cjs/react.development.js:188:36 in warningWithoutStack
- node_modules/react/cjs/react.development.js:603:32 in warning
- node_modules/react/cjs/react.development.js:1730:14 in createElementWithValidation
* src/screens/tasks-scr.js:91:25 in render
- node_modules/react-native/Libraries/Renderer/oss/ReactNativeRenderer-dev.js:11581:21 in finishClassComponent
- node_modules/react-native/Libraries/Renderer/oss/ReactNativeRenderer-dev.js:11509:4 in updateClassComponent
- ... 15 more stack frames from framework internals
Invariant Violation: Invariant Violation: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in, or you might have mixed up default and named imports.
Check the render method of `TasksScreen`.
- node_modules/react-native/Libraries/Renderer/oss/ReactNativeRenderer-dev.js:5716:10 in createFiberFromTypeAndProps
- node_modules/react-native/Libraries/Renderer/oss/ReactNativeRenderer-dev.js:5744:4 in createFiberFromElement
- ... 19 more stack frames from framework internals
Warning: Can't perform a React state update on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and asynchronous tasks in %s.%s, the componentWillUnmount method,
in TabBar (at MaterialTopTabBar.tsx:92)
in TabBarTop (at createMaterialTopTabNavigator.tsx:84)
in Pager (at TabView.tsx:70)
in RCTView (at View.js:45)
in View (at TabView.tsx:128)
in TabView (at createMaterialTopTabNavigator.tsx:136)
in MaterialTabView (at createTabNavigator.tsx:228)
in NavigationView (at createNavigator.js:80)
in Navigator (at SceneView.js:9)
in SceneView (at StackViewLayout.tsx:889)
in RCTView (at View.js:45)
in View (at StackViewLayout.tsx:888)
in RCTView (at View.js:45)
in View (at StackViewLayout.tsx:887)
in RCTView (at View.js:45)
in View (at createAnimatedComponent.js:151)
in AnimatedComponent (at StackViewCard.tsx:106)
in RCTView (at View.js:45)
in View (at createAnimatedComponent.js:151)
in AnimatedComponent (at screens.native.js:71)
in Screen (at StackViewCard.tsx:93)
in Card (at createPointerEventsContainer.tsx:95)
in Container (at StackViewLayout.tsx:975)
in RCTView (at View.js:45)
in View (at screens.native.js:101)
in ScreenContainer (at StackViewLayout.tsx:384)
in RCTView (at View.js:45)
in View (at createAnimatedComponent.js:151)
in AnimatedComponent (at StackViewLayout.tsx:374)
in PanGestureHandler (at StackViewLayout.tsx:367)
in StackViewLayout (at withOrientation.js:30)
in withOrientation (at StackView.tsx:104)
in RCTView (at View.js:45)
in View (at Transitioner.tsx:267)
in Transitioner (at StackView.tsx:41)
in StackView (at createNavigator.js:80)
in Navigator (at createKeyboardAwareNavigator.js:12)
in KeyboardAwareNavigator (at SceneView.js:9)
in SceneView (at StackViewLayout.tsx:889)
in RCTView (at View.js:45)
in View (at StackViewLayout.tsx:888)
in RCTView (at View.js:45)
in View (at StackViewLayout.tsx:887)
in RCTView (at View.js:45)
in View (at createAnimatedComponent.js:151)
in AnimatedComponent (at StackViewCard.tsx:106)
in RCTView (at View.js:45)
in View (at createAnimatedComponent.js:151)
in AnimatedComponent (at screens.native.js:71)
in Screen (at StackViewCard.tsx:93)
in Card (at createPointerEventsContainer.tsx:95)
in Container (at StackViewLayout.tsx:975)
in RCTView (at View.js:45)
in View (at screens.native.js:101)
in ScreenContainer (at StackViewLayout.tsx:384)
in RCTView (at View.js:45)
in View (at createAnimatedComponent.js:151)
in AnimatedComponent (at StackViewLayout.tsx:374)
in PanGestureHandler (at StackViewLayout.tsx:367)
in StackViewLayout (at withOrientation.js:30)
in withOrientation (at StackView.tsx:104)
in RCTView (at View.js:45)
in View (at Transitioner.tsx:267)
in Transitioner (at StackView.tsx:41)
in StackView (at createNavigator.js:80)
in Navigator (at createKeyboardAwareNavigator.js:12)
in KeyboardAwareNavigator (at createAppContainIjs:430)
- node_modules/expo/build/environment/muteWarnings.fx.js:27:24 in error
在此先感谢大家！
答案 0 :(得分：1)
此库中没有DatePicker组件。但是，有Datepicker