小编use*_*500的帖子

我正在制作一个React应用程序,允许你创建一个列表并保存它,但React一直在给我一个警告,我的元素没有唯一的关键道具(元素List/ListForm).我应该如何为用户创建的元素创建唯一的关键道具？下面是我的React代码

var TitleForm = React.createClass({
    handleSubmit: function(e) {
        e.preventDefault();
        var listName = {'name':this.refs.listName.value};
        this.props.handleCreate(listName);
        this.refs.listName.value = "";
    },
    render: function() {
        return (
            <div>
                <form onSubmit={this.handleSubmit}>
                    <input className='form-control list-input' type='text' ref='listName' placeholder="List Name"/>
                    <br/>
                    <button className="btn btn-primary" type="submit">Create</button>
                </form>
            </div>
        );
    }
});

var ListForm = React.createClass({
    getInitialState: function() {
        return {items:[{'name':'item1'}],itemCount:1};
    },
    handleSubmit: function(e) {
        e.preventDefault();
        var list = {'name': this.props.name, 'data':[]};
        var items = this.state.items;
        for (var i = 1; i < items.length; i++) {
            list.data.push(this.refs[items[i].name]);
        }
        this.props.update(list); …

我目前有两个文件,一个app.js和一个index.html,当我尝试使用一些CSS类渲染一个表单时,HTML元素显示但缺少类.

这是我的app.js:

var Form = React.createClass({
    handleClick: function() {
        alert('click')
    },
    render: function() {
        return (
            <div>
                <input class='form-control' type='text' name='list-name'/>
                <button class="btn btn-primary" onClick={this.handleClick}>Submit</button>
            </div>
        );
    }
});

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

这是我的HTML正文:

<div class="container">
    <h1>Title</h1>
    <div id="app" class="center"></div>
</div>

下面的代码是我到目前为止的代码.当它写入.csv时,它会覆盖我之前在文件中写入的内容.如何以不擦除我之前文本的方式写入文件.(我的代码的目标是拥有一个人输入他们的名字并让程序记住它们)

def main(src):
    try:
        input_file = open(src, "r")
    except IOError as error:
        print("Error: Cannot open '" + src + "' for processing.")
    print("Welcome to Learner!")
    print("What is your name? ")
    name = input()
    for line in input_file:
        w = line.split(",")
        for x in w:    
            if x.lower() == name.lower():
                print("I remember you "+ name.upper())
            else:
                print("NO")
                a = open("learner.csv", "w")
                a.write(name)
                a.close()
                break
if __name__ == "__main__":
    main("learner.csv")

所以我有一个问候程序,旁边有3个JTextfields和3个JLabel,我想添加助记符,我相信这是JTextField旁边的JLabel中其中一个字母下面的小写下划线.当用户按下Alt +带下划线的键时,光标将转到它旁边的JTextfield.这是我的代码,所以只显示没有助记符的简单问候语

import javax.swing.*;
import javax.swing.UIManager.LookAndFeelInfo;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class GreetingApp extends JFrame {
    private static final long serialVersionUID = 1L;
    private final JTextField firstNameField,middleNameField,lastNameField;
    private final JButton greetingButton;
    public GreetingApp() {
        super("Greetings");
        this.firstNameField = new JTextField(8);
        this.middleNameField = new JTextField(8);
        this.lastNameField = new JTextField(8);
        this.greetingButton = new JButton("Get Greeting"); 

        greetingButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(final ActionEvent ae){
                showGreeting();
            }
        });
        final Container mainPanel = getContentPane();
        mainPanel.setLayout(new BorderLayout());
        final JPanel inputPanel = new JPanel();
        final …

所以目前我的程序只显示GUI右下角的一个按钮.但我想在右下角显示两个按钮.任何想法如何将两个按钮设置到右上角？到目前为止,这是我的代码:

import javax.swing.*;

import java.awt.*;

public class Other extends JFrame{
        private static final long serialVersionUID = 1L;
        public Other() {
            super("Buttons");
            final Container mainPanel = getContentPane();
            mainPanel.setLayout(new BorderLayout());
            JPanel buttonPanel = new JPanel();
            buttonPanel.setLayout(new BorderLayout());
            JPanel inputPanel = new JPanel();
            inputPanel.add(new JLabel("RANDOM TEXT HERE"));
            inputPanel.add(new JLabel("RANDOM TEXT HERE"));
            inputPanel.add(new JLabel("RANDOM TEXT HERE"));
            JButton s = new JButton("first");
            JButton l = new JButton("second");
            buttonPanel.add(s,BorderLayout.LINE_END);
            buttonPanel.add(l,BorderLayout.LINE_END); //<-- not working
            mainPanel.add(inputPanel,BorderLayout.PAGE_START);
            mainPanel.add(buttonPanel,BorderLayout.PAGE_END);
            pack();
            setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            setLocationRelativeTo(null);
            setVisible(true);
        }
   public static void main(String[] …