我正在使用React Native开发一个与Firebase链接的简单待办事项应用程序。我有一个类,其中包含几个方法。根据我在线搜索到的信息,似乎是渲染函数中的输出相关问题。但我检查了我的方法,无法确定确切的问题。以下是我的类:
![enter image description here](https://istack.dev59.com/Lfp3X.webp)
class ToDo_React extends Component {
constructor(props) {
super(props);
var myFirebaseRef = new Firebase(' ');
this.itemsRef = myFirebaseRef.child('items');
this.state = {
newTodo: '',
todoSource: new ListView.DataSource({rowHasChanged: (row1, row2) => row1 !== row2})
};
this.items = [];
}
componentDidMount() {
// When a todo is added
this.itemsRef.on('child_added', (dataSnapshot) => {
this.items.push({id: dataSnapshot.key(), text: dataSnapshot.val()});
this.setState({
todoSource: this.state.todoSource.cloneWithRows(this.items)
});
});
this.itemsRef.on('child_removed', (dataSnapshot) => {
this.items = this.items.filter((x) => x.id !== dataSnapshot.key());
this.setState({
todoSource: this.state.todoSource.cloneWithRows(this.items)
});
});
}
addTodo() {
if (this.state.newTodo !== '') {
this.itemsRef.push({
todo: this.state.newTodo
});
this.setState({
newTodo : ''
});
}
}
removeTodo(rowData) {
this.itemsRef.child(rowData.id).remove();
}
render() { return (
<View style={styles.appContainer}>
<View style={styles.titleView}>
<Text style={styles.titleText}>
My Todos
</Text>
</View>
<View style={styles.inputcontainer}>
<TextInput style={styles.input} onChangeText={(text) => this.setState({newTodo: text})} value={this.state.newTodo}/>
<TouchableHighlight
style={styles.button}
onPress={() => this.addTodo()}
underlayColor='#dddddd'>
<Text style={styles.btnText}>Add!</Text>
</TouchableHighlight>
</View>
<ListView
dataSource={this.state.todoSource}
renderRow={this.renderRow.bind(this)} />
</View>
);
}
renderRow(rowData) {
return (
<TouchableHighlight
underlayColor='#dddddd'
onPress={() => this.removeTodo(rowData)}>
<View>
<View style={styles.row}>
<Text style={styles.todoText}>{rowData.text}</Text>
</View>
<View style={styles.separator} />
</View>
</TouchableHighlight>
);
}
}