React本機onPress正在加載調用

Question

我想傳遞一個參數給我的函數，但每當我加載頁面這個get的調用。我也試過（）=> this.loadStories（'bloomberg'），但這似乎沒有工作。這是我的代碼。

class Main extends Component { 

constructor() { 
    super(); 
    this.loadStories = this.loadStories('channel').bind(this); 
} 

componentDidMount(){ 

} 

loadStories(channel) { 
    this.props.getStories(channel); 
} 

render() { 
    return (
    <ScrollView> 
     <View style={{marginTop: 20}}> 

     <Button onPress={this.loadStories('bloomberg')} title="Top Stories"></Button> 


     {this.props.stories.map(function(item, index){ 
     return(
      <View key={index} style={{marginBottom: 10, padding: 10}}> 
      <Text>{item.title}</Text> 
      <Text>{item.description}</Text> 
      </View> 
     ) 
     })} 
    </View> 

    </ScrollView> 
); 
} 
} 

Answer 1

您可以執行以下操作以防止直接方法（函數）調用的問題，您有：

class Main extends Component { 
    constructor() { 
    // Step #1: Delete this line. You can't bind like this. 
    // this.loadStories = this.loadStories('channel').bind(this); 
    } 

    /* ... */ 

    render() { 
    return (
     <ScrollView> 
     <View style={{marginTop: 20}}> 
      { /* Step #2: bind inline and pass 'bloomberg' like so: */ } 
      <Button onPress={this.loadStories.bind(this, 'bloomberg')} title="Top Stories"> 
      </Button> 
     </View> 

     { /* ... */ } 
     </ScrollView> 
    ); 
    } 
}