Win Form：SaveFileDialog

Question

我将以下代码添加到保存按钮：

if (saveFileDialog1.ShowDialog() == DialogResult.OK)
{                
    FileStream fs = new FileStream(saveFileDialog1.FileName, FileMode.Create);
    StreamWriter writer = new StreamWriter(fs);
    writer.Write(twexit.Text);       // twexit is previously created  
    writer.Close();
    fs.Close();
}

当我键入文件名并单击“保存”时，表示该文件不存在。我知道它不存在，但我设置了FileMode.Create。那么，如果它不存在，它不应该创建文件吗？

Answer 1

SaveFileDialog中有一个选项CheckFileExists，如果所选文件不存在，将导致对话框显示该消息。您应该将此设置保留为false（这是默认值）。

Answer 2

你可以简单地使用它：

File.WriteAllText(saveFileDialog1.FileName, twexit.Text);

而不是很多代码与流。它会创建新文件或覆盖它。 文件是System.Io的类。如果您想说文件是否存在，请使用

File.Exist(filePath)

再见

Answer 3

像这样使用：

     SaveFileDialog dlg = new SaveFileDialog();

        dlg.Filter = "csv files (*.csv)|*.csv";
        dlg.Title = "Export in CSV format";

        //decide whether we need to check file exists
        //dlg.CheckFileExists = true;

        //this is the default behaviour
        dlg.CheckPathExists = true;

        //If InitialDirectory is not specified, the default path is My Documents
        //dlg.InitialDirectory = Application.StartupPath;

        dlg.ShowDialog();
        // If the file name is not an empty string open it for saving.
        if (dlg.FileName != "")

        //alternative if you prefer this
        //if (dlg.ShowDialog() == System.Windows.Forms.DialogResult.OK
            //&& dlg.FileName.Length > 0)

        {
            StreamWriter streamWriter = new StreamWriter(dlg.FileName);
            streamWriter.Write("My CSV file\r\n");
            streamWriter.Write(DateTime.Now.ToString());
            //Note streamWriter.NewLine is same as "\r\n"
            streamWriter.Write(streamWriter.NewLine);
            streamWriter.Write("\r\n");
            streamWriter.Write("Column1, Column2\r\n");
            //…
            streamWriter.Close();
        }

        //if no longer needed
        //dlg.Dispose();