从 React js 中的列表中删除项目 [英] Remove items form the list in React js

问题描述

我正在创建一个待办事项应用程序 &当我们单击它们时，我无法编写用于删除列表元素的代码.我希望在用户点击时删除特定项目

class Todo 扩展 React.Component {构造函数(道具){超级(道具)；this.state={todos:[]};}保存() {var todos = [...this.state.todos];todos.push(this.newText.value);this.setState({todos});}去掉{}使成为(){返回(<div className="list"><h1>待办事项清单</h1><input type="text" ref={(ip) =>{this.newText = ip}}/><button onClick={this.save.bind(this)} className="btn btn-primary glyphicon glyphicon-floppy-saved">保存<ul>{this.state.todos.map(function(todo) {返回 
{todo}
})}

)}};

解决方案

您需要传递待办事项的索引，然后使用 javascript 中的 slice 函数将其删除，例如

remove(e, index){var todos = [...this.state.todos];todos.slice(index, 1);this.setState({todos})}

class Todo extends React.Component {构造函数(道具){超级(道具)；this.state={todos:[]};}保存() {var todos = [...this.state.todos];todos.push(this.newText.value);this.setState({todos});}删除Todo(索引){控制台日志(索引)var todos = [...this.state.todos];todos.splice(索引，1)this.setState({todos})}使成为(){返回(<div className="list"><h1>待办事项清单</h1><input type="text" ref={(ip) =>{this.newText = ip}}/><button onClick={this.save.bind(this)} className="btn btn-primary glyphicon glyphicon-floppy-saved">保存<ul>{this.state.todos.map(function(todo, index) {return 
{todo}
}.bind(this))}

)}};ReactDOM.render(, document.getElementById('app'))

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script><script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script><div id="app"></div>

I am creating a To-do app & I am not able to write the code for deleting the elements of the list when we click them. I want the specific item to delete when a user clicks on it

class Todo extends React.Component {

    constructor(props) {
      super(props);
      this.state={todos:[]};
    }

    save() {
      var todos = [...this.state.todos];
      todos.push(this.newText.value);
      this.setState({todos});
    }

    remove{

    }


    render(){
        return(
            <div className="list">
              <h1> TO-DO List</h1>
              <input type="text" ref={(ip) => {this.newText = ip}}/>
              <button onClick={this.save.bind(this)} className="btn btn-primary glyphicon glyphicon-floppy-saved">Save
              </button>
              <ul>
                {this.state.todos.map(function(todo) {
                      return <li>{todo}</li>

                 })}

              </ul>
            </div>
        )
    }
};

解决方案

You need to pass on the index of the todo and then remove that using the slice function in javascript like

remove(e, index){
      var todos = [...this.state.todos];
      todos.slice(index, 1);
      this.setState({todos})
}

class Todo extends React.Component {

    constructor(props) {
      super(props);
      this.state={todos:[]};
    }

    save() {
      var todos = [...this.state.todos];
      todos.push(this.newText.value);
      this.setState({todos});
    }

    deleteTodo(index){
        console.log(index)
         var todos = [...this.state.todos];
         todos.splice(index, 1)
         this.setState({todos})
    }


    render(){
        return(
            <div className="list">
              <h1> TO-DO List</h1>
              <input type="text" ref={(ip) => {this.newText = ip}}/>
              <button onClick={this.save.bind(this)} className="btn btn-primary glyphicon glyphicon-floppy-saved">Save
              </button>
              <ul>
                {this.state.todos.map(function(todo, index) {
                      return <li key={index} onClick={this.deleteTodo.bind(this, index)}>{todo}</li>

                 }.bind(this))}

              </ul>
            </div>
        )
    }
};

ReactDOM.render(<Todo/>, document.getElementById('app'))

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<div id="app"></div>

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