Question

我有这个xml文件，现在我想在我的xml文件中添加新条目

之前：

 <?xml version="1.0" encoding="utf-8"?>
<email>
  <builderemail>
    <builder>
      <id>1</id>
      <value>builder@xyz.com</value>
    </builder>
  </builderemail>
  <manageremail>
    <manager>
      <id>1</id>
      <value>manager@xyz.com</value>
    </manager>
    </manageremail>
</email>

后：

 <?xml version="1.0" encoding="utf-8"?>
<email>
  <builderemail>
    <builder>
      <id>1</id>
      <value>builder@xyz.com</value>
      <id>2</id>
      <value>Others</value>
    </builder>
  </builderemail>
  <manageremail>
    <manager>
      <id>1</id>
      <value>manager@xyz.com</value>
      <id>2</id>
      <value>Others</value>
    </manager>
    </manageremail>
</email>

我的代码c＃代码：

protected void Page_Load(object sender, EventArgs e)
{
    TextBox1.Visible = false;
    Button1.Visible = false;
    TextBox2.Visible = false;
    Button2.Visible = false;
    if (!IsPostBack)
    {
        PopulateDDLFromXMLFile();
    }
}
public void PopulateDDLFromXMLFile()
{
    DataSet ds = new DataSet();
    ds.ReadXml(MapPath("~/App_Data/builderemail.xml"));

    //get the dataview of table "Country", which is default table name
    DataView dv = ds.Tables["builder"].DefaultView;
    DataView dw = ds.Tables["manager"].DefaultView;
    //or we can use:
    //DataView dv = ds.Tables[0].DefaultView;

    //Now sort the DataView vy column name "Name"
    dv.Sort = "value";

    //now define datatext field and datavalue field of dropdownlist
    DropDownList1.DataTextField = "value";
    DropDownList1.DataValueField = "ID";
    DropDownList2.DataTextField = "value";
    DropDownList2.DataValueField = "ID";

    //now bind the dropdownlist to the dataview
    DropDownList1.DataSource = dv;
    DropDownList1.DataBind();
    DropDownList2.DataSource = dw;
    DropDownList2.DataBind();
}

然而，这不起作用。我将收到IndexOutOfRangeException错误。我该如何处理？

Answer 1

“IndexOutOfRange”异常是因为这行代码：

dv.Sort = "value"; //because the Table "builder" doesn't have the "value" column

PopulateDDLFromXMLFile方法适用于xml的第一个版本。 xml的更高版本不是有效版本，并不表示您希望/尝试在PopulateDDLFromXMLFile方法中执行的操作。

DataSet ds = new DataSet();
ds.ReadXml(MapPath("~/App_Data/builderemail.xml"));

在较新的xml上调用上面的代码会创建6个表，一个用于builderemail，builder，id，value，manageremail和manager。

但是代码假定id和value是builder表中的列。因此上述例外。

我建议您将xml修改为：

<?xml version="1.0" encoding="utf-8" ?>
<email>
    <builderemail>
        <builder>
            <id>1</id>
            <value>builder@xyz.com</value>
        </builder>
        <builder>
            <id>2</id>
            <value>Others</value>
            </builder>
    </builderemail>
    <manageremail>
        <manager>
            <id>1</id>
            <value>manager@xyz.com</value>
        </manager>
            <manger>
                <id>2</id>
                <value>Others</value>
            </manger>
    </manageremail>
</email>

数据绑定xml列表到asp.net下拉列表的问题

1 个答案: