尝试制作一个简单的待办事项清单。我的AddTodo组件运行正常,我不认为这是导致此问题的原因,但是我的Flatlist并未显示数据。我不知道为什么,因为没有错误。无论是否使用滚动视图,都会出现该问题。
我尝试弄乱项目的宽度和高度以及列表本身,但似乎没有办法解决问题。
我的mainTodo文件:
import React, { Component } from 'react';
import { Text, View, StyleSheet, FlatList, ScrollView } from 'react-native';
import AddTodo from './AddTodo';
import TodoItem from './TodoItem';
class MainTodo extends Component {
constructor() {
super();
this.state = {
textInput: '',
todos: [
{ id: 0, title: 'walk rocky', completed: false },
{ id: 1, title: 'pickup dinner', completed: false }
]
};
}
addNewTodo() {
let todos = this.state.todos;
todos.unshift({
id: todos.length + 1,
todo: this.state.textInput,
completed: false
});
this.setState({
todos,
textInput: ''
});
}
render() {
return (
<View style={{ flex: 1 }}>
<AddTodo
textChange={textInput => this.setState({ textInput })}
addNewTodo={() => this.addNewTodo()}
textInput={this.state.textInput}
/>
<ScrollView>
<FlatList
style={{ flex: 1 }}
data={this.state.todos}
extraData={this.state}
keyExtractor={(item, index) => index.toString()}
renderItem={({ item }) => {
return (
<TodoItem todoItem={item} />
);
}}
/>
</ScrollView>
</View>
);
}
}
export default MainTodo;
我的TodoItem文件:
import React, { Component } from 'react';
import { StyleSheet, Text, TouchableOpacity, View } from 'react-native';
class TodoItem extends Component {
render() {
const todoItem = this.props.todoItem;
return (
<View>
<TouchableOpacity style={styles.todoItem}>
<Text style={(todoItem.completed) ? { color: '#aaaaaa' } : { color: '#313131' }}>
{todoItem.title}
</Text>
</TouchableOpacity>
</View>
);
}
}
const styles = StyleSheet.create({
todoItem: {
width: 40,
height: 40,
borderBottomColor: '#DDD',
borderBottomWidth: 1,
flexDirection: 'row',
alignItems: 'center',
justifyContent: 'space-between',
paddingLeft: 15
}
});
export default TodoItem;
在我的addtodo组件下,什么都没有显示,只是一个空白屏幕。
答案 0 :(得分:0)
在maintodo
文件中,您正在渲染AddTodo component
,但是我没有看到您的AddTodo component
。因此,您可以相应地更新代码。
在TodoItem
中,删除应用于style
的{{1}},使您的代码看起来像
TouchableOpacity
在import React, { Component } from 'react';
import { StyleSheet, Text, TouchableOpacity, View } from 'react-native';
class TodoItem extends Component {
render() {
const todoItem = this.props.todoItem;
return (
<View>
<TouchableOpacity style={styles.todoItem}>
<Text style={(todoItem.completed) ? { color: '#aaaaaa' } : { color: '#313131' }}>
{todoItem.title}
</Text>
</TouchableOpacity>
</View>
);
}
}
const styles = StyleSheet.create({
});
export default TodoItem;
将您的MainTodo
函数更新为
addNewTodo
以父addNewTodo = () => {
const todo = {
id: this.state.todos.length,
title: this.state.textInput,
completed: false
}
this.setState({todos: [...this.state.todos, todo ], textInput: ""})
}
为TextInput
创建Button
和View
,因此,flexDirection: "row"
更改后,其值为TextInput
,而{按下{1}}将会创建新的set in the textInput
并将其添加到Button
并将object
的值设置为空。
,最终代码可以为
todos
答案 1 :(得分:0)
使用代码
mainTodo文件:
import React, { Component } from 'react';
import { Text, View, StyleSheet, FlatList, ScrollView } from 'react-native';
import AddTodo from './AddTodo';
import TodoItem from './TodoItem';
class MainTodo extends Component {
constructor() {
super();
this.state = {
textInput: '',
todos: [
{ id: 0, title: 'walk rocky', completed: false },
{ id: 1, title: 'pickup dinner', completed: false }
]
};
}
addNewTodo() {
let todos = this.state.todos;
todos.unshift({
id: todos.length + 1,
todo: this.state.textInput,
completed: false
});
this.setState({
todos,
textInput: ''
});
}
render() {
return (
<View style={{ flex: 1 }}>
<AddTodo
textChange={textInput => this.setState({ textInput })}
addNewTodo={() => this.addNewTodo()}
textInput={this.state.textInput}
/>
<ScrollView>
<FlatList
style={{ flex: 1 }}
data={this.state.todos}
extraData={this.state}
keyExtractor={(item, index) => index.toString()}
renderItem={({ item }) => {
return (
<TodoItem todoItem={item} />
);
}}
/>
</ScrollView>
</View>
);
}
}
export default MainTodo;
TodoItem文件:
import React, { Component } from 'react';
import { StyleSheet, Text, TouchableOpacity, View } from 'react-native';
class TodoItem extends Component {
render() {
const todoItem = this.props.todoItem;
return (
<View>
<TouchableOpacity style={styles.todoItem}>
<Text style={(todoItem.completed) ? { color: '#aaaaaa' } : { color: '#313131' }}>
{todoItem.title}
</Text>
</TouchableOpacity>
</View>
);
}
}
const styles = StyleSheet.create({
todoItem: {
width: 40,
height: 40,
borderBottomColor: '#DDD',
borderBottomWidth: 1,
backgroundColor:'red',
flexDirection: 'row',
alignItems: 'center',
justifyContent: 'space-between',
paddingLeft: 15
}
});
export default TodoItem;