如何使用 TXT 文件不断更新 RichTextBox？

Question

我有这段代码，它应该让 richTextBox2 随时更新 usedPath 的内容，但它没有。

 private void watch()
    {
        var usedPath = Path.Combine(Directory.GetCurrentDirectory(), "usedwords.txt");

        FileSystemWatcher watcher = new FileSystemWatcher();
        watcher.Path = usedPath;
        watcher.NotifyFilter = NotifyFilters.LastWrite;
        watcher.Filter = "*.txt*";
        watcher.Changed += new FileSystemEventHandler(OnChanged);
        watcher.EnableRaisingEvents = true;
    }

    private void OnChanged(object source, FileSystemEventArgs e)
    {
        string usedPath = Path.Combine(Directory.GetCurrentDirectory(), "usedwords.txt");
        richTextBox2.LoadFile(usedPath, RichTextBoxStreamType.PlainText);
    }

谁能帮我弄清楚我哪里错了？

Answer 1

问题1：你的watcher.Path = 单个文件的路径，会报错。

解决方案：看这个：Use FileSystemWatcher on a single file in C#

watcher.Path = Path.GetDirectoryName(filePath1); 
watcher.Filter = Path.GetFileName(filePath1);

问题2：在OnChanged()中访问richTextBox2会导致跨线程错误

解决方案：使用这个：

private void OnChanged(object source, FileSystemEventArgs e)
{
    Invoke((MethodInvoker)delegate
    {
          string usedPath = Path.Combine(Directory.GetCurrentDirectory(), "usedwords.txt");
          richTextBox2.LoadFile(usedPath, RichTextBoxStreamType.PlainText);      
    });
}

问题 3：在其他程序正在写入时尝试 LoadFile 时可能会出错。

（可能的）解决方案：在尝试将LoadFile 放入OnChanged 之前，先放入Thread.Sleep(10)

    private void OnChanged(object source, FileSystemEventArgs e)
    {
        Thread.Sleep(10);
        Invoke((MethodInvoker)delegate
        {
            richTextBox1.LoadFile(usedPath, RichTextBoxStreamType.PlainText);
        });
    }

我的完整代码：

public partial class Form1 : Form
{
    string usedPath = @"C:\Users\xxx\Desktop\usedwords.txt";

    public Form1()
    {
        InitializeComponent();
        watch();
    }

    private void watch()
    {
        FileSystemWatcher watcher = new FileSystemWatcher();
        watcher.Path = Path.GetDirectoryName(usedPath);
        watcher.Filter = Path.GetFileName(usedPath);
        watcher.NotifyFilter = NotifyFilters.LastWrite;
        watcher.Changed += new FileSystemEventHandler(OnChanged);
        watcher.EnableRaisingEvents = true;
    }

    private void OnChanged(object source, FileSystemEventArgs e)
    {
        Thread.Sleep(10);
        Invoke((MethodInvoker)delegate
        {
            richTextBox1.LoadFile(usedPath, RichTextBoxStreamType.PlainText);
        });
    }
}