关于 c#:empty path name not legal

empty path name not legal

我有一个"保存"按钮，所以当用户点击时，它会保存 xml 文件(xml 序列化)。此处使用了保存文件对话框，当我在未选择任何文件的情况下按取消时，会出现"参数异常"并显示"空路径名不合法"。我该如何处理这个异常？即使在保存文件对话框中没有选择任何路径，我也希望表单保持不变。非常感谢。

我的存档对话框片段：

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private void SaveButton_Click(object sender, RoutedEventArgs e)
{
string savepath;
SaveFileDialog DialogSave = new SaveFileDialog();
// Default file extension
DialogSave.DefaultExt ="txt";
// Available file extensions
DialogSave.Filter ="XML file (*.xml)|*.xml|All files (*.*)|*.*";
// Adds a extension if the user does not
DialogSave.AddExtension = true;
// Restores the selected directory, next time
DialogSave.RestoreDirectory = true;
// Dialog title
DialogSave.Title ="Where do you want to save the file?";
// Startup directory
DialogSave.InitialDirectory = @"C:/";
DialogSave.ShowDialog();
savepath = DialogSave.FileName;
DialogSave.Dispose();
DialogSave = null;
...
using (Stream savestream = new FileStream(savepath, FileMode.Create))
{
XmlSerializer serializer = new XmlSerializer(typeof(FormSaving));
serializer.Serialize(savestream, formsaving);
}

}

我的参数异常发生在这一行：

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using (Stream savestream = new FileStream(savepath, FileMode.Create))
{
XmlSerializer serializer = new XmlSerializer(typeof(FormSaving));
serializer.Serialize(savestream, formsaving);
}

这里的问题是您不关心"保存"对话框的结果，即使用户单击了"取消"，您也会尝试保存。您应该将代码更改为如下所示：

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...
DialogSave.InitialDirectory = @"C:/";
if( DialogSave.ShowDialog() == DialogResult.OK )
{
savepath = DialogSave.FileName;
DialogSave = null;
...
using (Stream savestream = new FileStream(savepath, FileMode.Create))
{
XmlSerializer serializer = new XmlSerializer(typeof(FormSaving));
serializer.Serialize(savestream, formsaving);
}
}
DialogSave.Dispose();