Winforms - 列表框在单击之前不会更新内容

Posted 2023-04-11

【中文标题】Winforms - 列表框在单击之前不会更新内容

【英文标题】：Winforms - Listbox will not update contenets until clicked

【发布时间】：2021-01-25 18:18:22

【问题描述】：

我会尽量添加所需的信息，如果您需要任何我没有添加的额外信息，请告诉我，我会尽力提供。

我的问题的基本原理是，当我按下按钮时，它会抓取我选择的文件并将其保存到文本文件中。这很好用，我可以根据需要保存尽可能多的文件。问题在于我的列表框的列表框。我的应用程序是一个音板，我希望将带有热键的文件名显示在 几乎 工作正常的列表框中。在加载应用程序时，列表框将获取所有保存的文件并相应地显示它们一次，在添加文件时，该文件将被添加到列表框并被保存。正如我所说，这几乎可以工作，因为出于某种我不知道的原因，您必须单击列表框才能添加内容。我的代码如下：

public partial class Form1 : Form

    public int getNumberOfSongs()
    
        using (Stream stream = File.Open(@"Sounds.txt", FileMode.Open))
        
            using (StreamReader reader = new StreamReader(stream))
            
                string line = null;
                for (int i = 0; i < 1; ++i)
                
                    line = reader.ReadLine();   
                    int ine = Int32.Parse(line);
                    ine = ine + 1;
                    return ine;
                
            
        
        return 8;
        //This is only here so it doesn't give me an error, it is never used
    


    public void fineChanger(string newText, string fileName, int line_to_edit)
    
        string[] arrLine = File.ReadAllLines(fileName);
        arrLine[line_to_edit] = newText;
        File.WriteAllLines(fileName, arrLine);
    
    public void addFile()
    
        OpenFileDialog openFileDialog = new OpenFileDialog();
        openFileDialog.InitialDirectory = "c:\\";
        openFileDialog.Filter = "WAV files (*.wav)|*.wav";
        openFileDialog.DefaultExt = ".wav";
        openFileDialog.FilterIndex = 2;
        openFileDialog.RestoreDirectory = true;
        if (openFileDialog.ShowDialog() == DialogResult.OK)
        
            //Get the path of specified file
            string filePath = openFileDialog.FileName;
            songToAdd = filePath;
            string control = filePath + "§modifier§hotkey";
            string savePath = @"Sounds.txt";
            int bruh = getNumberOfSongs();
            fineChanger(control, savePath, bruh);
            string bru = bruh.ToString();
            fineChanger(bru, savePath, 0);
            add = true;
        
    
    public bool add = false;
    public string songToAdd;
    public bool load = true;

    public Form1()
    
        InitializeComponent();
    

    public void button1_Click(object sender, EventArgs e)
    
        addFile();
    

    private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
    
        if (load == true)
        
            listBox1.DataSource = File.ReadAllLines(@"Sounds.txt");
            load = false;
        
        if(add == true)
        
            listBox1.Items.Add(songToAdd);
            add = false;
                    
    

附：我仍然是 Windows 窗体的新手，而且这个应用程序还远未完成。

【问题讨论】：

您实际上只是将数据添加到 SelectedIndexChanged 中的listBox1.Items。为什么不在addFile末尾做呢？

不敢相信我没有想到这个，让我试试这个。

getNumberOfSongs - 这个方法有不少问题，

【参考方案1】：

我没有在 SelectedIndexChanged 中添加项目，而是将它们添加到外部。我在Form1_Load 中加载保存的歌曲，并在addFile() 函数中打开/保存加载的文件。 编辑代码：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
using System.Media;
using System.Security.Cryptography.X509Certificates;
using System.Runtime;
using System.Runtime.InteropServices;
using Microsoft.VisualBasic;
using System.Diagnostics;

namespace SoundBoard

    public partial class Form1 : Form
    
        public int getNumberOfSongs()
        
            using (Stream stream = File.Open(@"Sounds.txt", FileMode.Open))
            
                using (StreamReader reader = new StreamReader(stream))
                
                    string line = null;
                    for (int i = 0; i < 1; ++i)
                    
                        line = reader.ReadLine();   
                        int ine = Int32.Parse(line);
                        ine = ine + 1;
                        return ine;
                    
                
            
            return 8;
            //This is only here so it doesn't give me an error, it is never used
        
        public bool load = true;
        
        public void fineChanger(string newText, string fileName, int line_to_edit)
        
            string[] arrLine = File.ReadAllLines(fileName);
            arrLine[line_to_edit] = newText;
            File.WriteAllLines(fileName, arrLine);
        
        public void addFile()
        
            OpenFileDialog openFileDialog = new OpenFileDialog();
            openFileDialog.InitialDirectory = "c:\\";
            openFileDialog.Filter = "WAV files (*.wav)|*.wav";
            openFileDialog.DefaultExt = ".wav";
            openFileDialog.FilterIndex = 2;
            openFileDialog.RestoreDirectory = true;
            if (openFileDialog.ShowDialog() == DialogResult.OK)
            
                //Get the path of specified file
                string filePath = openFileDialog.FileName;
                string control = filePath + "§modifier§hotkey";
                string savePath = @"Sounds.txt";
                int bruh = getNumberOfSongs();
                fineChanger(control, savePath, bruh);
                string bru = bruh.ToString();
                fineChanger(bru, savePath, 0);
                listBox1.Items.Add(filePath);
            
        
        public bool loada = true;

        public Form1()
        
            InitializeComponent();
        

        public void button1_Click(object sender, EventArgs e)
        
            addFile();
        
        private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
        

        

        private void Form1_Load(object sender, EventArgs e)
        
            if (loada == true)
            
                listBox1.Items.Add(File.ReadAllLines(@"Sounds.txt"));
                loada = false;