Question

所以，我是C＃的新手，我的程序中有这个列表框，它复制了它从文本框中读取的内容。每当我启动程序时，它会将save.txt文件的内容加载到列表框中，但是当它执行此操作时，它会加载所有save.txt内容的副本。我在加载内容之前尝试清除列表框但它没有工作。

这是我的代码：

    private void readList()
    {
        string line;
        listBox.Items.Clear(); //I tried to clear the listbox but it's not working
        listBox.Items.AddRange(File.ReadAllLines(@"C:\Users\Paul.DESKTOP-HGGDG1D\Desktop\My C# apps\MyAgenda\MyAgenda\MyAgenda\bin\Debug\save.txt"));
        using (StreamReader sr = new StreamReader("save.txt"))
            while ((line = sr.ReadLine()) != null)
            {
                listBox.Items.Add(line);
            }
    }

    public myAgenda()
    { 
        InitializeComponent();
        readList(); 
    }

    private void add_btn_Click(object sender, EventArgs e)
    {

        if (string.IsNullOrWhiteSpace(add_txt.Text))
        {
            MessageBox.Show("Error: Please enter a value");
        }
        else
        {
            holder = add_txt.Text;
            listBox.Items.Add(ctr + " " + holder);
            ctr++;
            add_txt.Text = " ";
        }
    }

    private void button1_Click(object sender, EventArgs e)
    {
        const string sPath = "save.txt";
        System.IO.StreamWriter SaveFile = new System.IO.StreamWriter(sPath);
        foreach (var item in listBox.Items)
        {
            SaveFile.WriteLine(item);
        }
        SaveFile.Close();
        Application.Exit();
    }

Answer 1

您在listbox方法中填写readlist两次，即

第一次：

  listBox.Items.AddRange(File.ReadAllLines(@"C:\Users\Paul.DESKTOP-HGGDG1D\Desktop\My C# apps\MyAgenda\MyAgenda\MyAgenda\bin\Debug\save.txt"));

第二次：

        using (StreamReader sr = new StreamReader("save.txt"))
        while ((line = sr.ReadLine()) != null)
        {
            listBox.Items.Add(line);
        }

您可以删除一种方法中的任何一种来填充内容。第一种方法最好用于可读性。

Answer 2

您正在listBox上复制内容两次。

尝试这样做：

private void readList()
{
    string line;
    listBox.Items.Clear(); 

    //Comment out this line then put the File Directory on the StreamReader
    //listBox.Items.AddRange(File.ReadAllLines(@"C:\Users\Paul.DESKTOP-HGGDG1D\Desktop\My C# apps\MyAgenda\MyAgenda\MyAgenda\bin\Debug\save.txt"));

    using (StreamReader sr = new StreamReader(@"C:\Users\Paul.DESKTOP-HGGDG1D\Desktop\My C# apps\MyAgenda\MyAgenda\MyAgenda\bin\Debug\save.txt"))
        while ((line = sr.ReadLine()) != null)
        {
            listBox.Items.Add(line);
        }
}

我的程序正在复制来自文本框C＃的输入流

2 个答案: