Question

好的，我已经做到了这一点，但现在我有点陷入困境。

我创建了一个保存并加载学生成绩的窗体。问题是保存和加载方向是硬编码的，我想使用filedialog来保存和加载文件。

我并不确定如何做到这一点。有什么想法吗？

private void btnLoad_Click(object sender, EventArgs e)
    {
        string filePath = @"C:\Users\grades.txt";
        if (File.Exists(filePath))
        {
            StreamReader stream = new StreamReader(filePath);
            txtResult.AppendText(stream.ReadToEnd());
            lblStatus.Text = "File Loaded";
        }
        else
            MessageBox.Show("There was a problem loading the file");
    }

    private void btnSave_Click(object sender, EventArgs e)
    {
        lblStatus.Text = "Entry saved";//shows in status label

        //string that specifies the location of the .txt file
         string filePath = @"C:\Users\grades.txt";

         StreamWriter fileWriter = new StreamWriter(filePath, true);//creates new object of class StreamWriter to be able to write to file

        //enters the information from the different textboxes to the file
        fileWriter.WriteLine(txtLastName.Text + ", " + txtFirstName.Text + ":\t" + Convert.ToString(txtID.Text) +
            "\t" + txtClass.Text + "\t" + txtGrades.Text);

        fileWriter.Close();//closes filewriter

    }

}

编辑：新代码有改进（我还没有实现Aybe的建议）。

我觉得我有点迟钝，但为什么这不起作用？在我看来，这应该有效，但它并没有。当我尝试加载文件时没有任何事情发生......

using System;
using System.Windows.Forms;
using System.IO;

namespace WindowsFormsApplication14
{
public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private void btnOpen_Click(object sender, EventArgs e)
    {
        var dlg = new OpenFileDialog();

        dlg.InitialDirectory = "c:\\";
        dlg.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*";
        dlg.FilterIndex = 2;
        dlg.RestoreDirectory = true;

        if (dlg.ShowDialog() != DialogResult.OK)
            return;

    }


    private void btnSave_Click(object sender, EventArgs e)
    {
        SaveFileDialog saveFileDialog1 = new SaveFileDialog();

        saveFileDialog1.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*";
        saveFileDialog1.FilterIndex = 2;
        saveFileDialog1.RestoreDirectory = true;

        if (saveFileDialog1.ShowDialog() == DialogResult.OK)
        {
            Stream myStream;
            if ((myStream = saveFileDialog1.OpenFile()) != null)
            {
                StreamWriter fileWriter = new StreamWriter(myStream);//creates new object of class StreamWriter to be able to write to file

                //enters the information from the different textboxes to the file
                fileWriter.WriteLine(txtLastName.Text + ", " + txtFirstName.Text + ":\t" + Convert.ToString(txtID.Text) +
                    "\t" + txtClass.Text + "\t" + txtGrades.Text);

                fileWriter.Close();//closes filewriter
                myStream.Close();
            }
        }

    }
}

}

Answer 1

Open和Save对话框实际上非常简单。

首先，您将初始化对话框：

SaveFileDialog saveFileDialog1 = new SaveFileDialog();

saveFileDialog1.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*"  ;
saveFileDialog1.FilterIndex = 2 ;
saveFileDialog1.RestoreDirectory = true ;

然后，您将显示它并等待用户导航到其路径并键入文件名：

if(saveFileDialog1.ShowDialog() == DialogResult.OK)
     {
         if((myStream = saveFileDialog1.OpenFile()) != null)
         {
             // Code to write the stream goes here.
             myStream.Close();
         }
     }

Answer 2

除@bwoogie回答外，利用using关键字轻松处理资源：

using System;
using System.IO;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void buttonOpen_Click(object sender, EventArgs e)
        {
            using (var dialog = new OpenFileDialog())
            {
                if (dialog.ShowDialog() != DialogResult.OK)
                    return;

                using (var reader = new StreamReader(dialog.OpenFile()))
                {
                    // TODO read file
                }
            }
        }

        private void buttonSave_Click(object sender, EventArgs e)
        {
            using (var dialog = new SaveFileDialog())
            {
                if (dialog.ShowDialog() != DialogResult.OK)
                    return;

                using (var writer = new StreamWriter(dialog.OpenFile()))
                {
                    // TODO save file
                }
            }
        }
    }
}

SaveFileDialog而不是硬编码保存方向

2 个答案: