Question

我正在尝试为“另存为...”菜单项编写代码。我的代码如下所示：

private void menuItem9_Click(object sender, EventArgs e)
{
    saveFileDialog1.Filter = ".XML file (*.xml)|*.xml";
    saveFileDialog1.FilterIndex = 1;
    saveFileDialog1.RestoreDirectory = true;
    saveFileDialog1.ShowDialog();
    XmlDocument document = new XmlDocument();

    string fileName = saveFileDialog1.FileName.ToString();
    document.Save(fileName+ ".xml");
    if (!File.Exists(fileName))
    {
        File.Create(fileName);
    }
}

基本上我想要做的就是使用“另存为”选项。点击它之后，我希望能够在我想要的任何地方保存带有不同名称的.xml文件。

Answer 1

由于XmlDocument不包含根节点，因此您的当前代码将引发异常。另请注意，SaveFileDialog's Filename属性还包含扩展名。

您可以使用

创建没有Root节点的新文件

SaveFileDialog saveFileDialog1 = new SaveFileDialog();

saveFileDialog1.Filter = ".XML file (*.xml)|*.xml";
saveFileDialog1.FilterIndex = 1;
saveFileDialog1.RestoreDirectory = true;

if (saveFileDialog1.ShowDialog() == System.Windows.Forms.DialogResult.OK)
{  
    File.Create(saveFileDialog1.FileName);
}

或者在保存之前确保您的XmlDocument具有根节点：

SaveFileDialog saveFileDialog1 = new SaveFileDialog();

saveFileDialog1.Filter = ".XML file (*.xml)|*.xml";
saveFileDialog1.FilterIndex = 1;
saveFileDialog1.RestoreDirectory = true;

if (saveFileDialog1.ShowDialog() == System.Windows.Forms.DialogResult.OK)
{
    XmlDocument document = new XmlDocument();
    document.AppendChild(document.CreateElement("Root"));
    document.Save(saveFileDialog1.FileName);
}

Answer 2

您新创建的XmlDocument文档实例没有任何根元素，因此XmlException

您可以避免使用saveFileDialog1.FileName.ToString()，因为saveFileDialog1.FileName已经是字符串值。

此代码

document.Save(fileName+ ".xml");

应该是

document.Save(saveFileDialog1.FileName);

Answer 3

private void menuItem9_Click(object sender, EventArgs e)
{
    saveFileDialog1.Filter = ".XML file (*.xml)|*.xml";
    saveFileDialog1.FilterIndex = 1;
    saveFileDialog1.RestoreDirectory = true;
    saveFileDialog1.ShowDialog();
    XmlDocument document = new XmlDocument();

    //Add this line of code
    document.LoadXml("<root></root>");

    string fileName = saveFileDialog1.FileName.ToString();
    // Save the document to a file
    XmlTextWriter writer = new XmlTextWriter(fileName,null);
    document.Save(writer);

}

“另存为...”菜单项

3 个答案: