将文件名添加到.txt文件时出现问题 [英] Problem in adding file names to .txt file

问题描述

当我尝试将文件名添加到列表时，我得到错误（对象引用没有设置为对象的实例）



button1_click ---用于获取textbox1的文件夹路径

button2_click ---用于存储文件名到列表

button3_click ---用于将文件名保存到report.txt

I,m getting error(object reference not set to an instance of an object) when i try to add file names to list

button1_click--- for getting the folder path to textbox1
button2_click--- for storing filenames to list
button3_click--- for saving filenames to report.txt

public partial class Form1 : Form
{
    List<string> fileStore = null;
    public Form1()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        FolderBrowserDialog folderBrowserDlg = new FolderBrowserDialog();
    
        folderBrowserDlg.ShowNewFolderButton = true;
      
        DialogResult dlgResult = folderBrowserDlg.ShowDialog();
        if (dlgResult.Equals(DialogResult.OK))
        {
        
            textBox1.Text = folderBrowserDlg.SelectedPath;
           
            Environment.SpecialFolder rootFolder = folderBrowserDlg.RootFolder;
        }
    }

    private void button2_Click(object sender, EventArgs e)
    {
         DirectoryInfo dir1 = new DirectoryInfo(textbox1.text);
        FileInfo[] files = dir1.GetFiles("*.*", SearchOption.AllDirectories);
        
        try
        {
            foreach (FileInfo f in files)
            {

                fileStore.Add(f.Name.ToString());

            }
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }  
    }

    private void button3_Click(object sender, EventArgs e)
    {
        const string sPath = "report.txt";

        System.IO.StreamWriter SaveFile = new System.IO.StreamWriter(sPath);
      
        foreach (string item in fileStore)
        {
             SaveFile.WriteLine(item.ToString());
        }
        
        SaveFile.Close();

        MessageBox.Show("Programs saved!");
    }
}

紧急情况已删除。

更正了格式和/或语法问题。

[/ Edit]

推荐答案

可能你需要像这样初始化你的fileStore变量：

Probably you need to initialize your "fileStore" variable like this :

List<string> fileStore = new List<string>();

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