为什么在尝试通过 Gridview 更新/删除一行时删除 XML 文件中的所有数据？

Question

我有一个可编辑的 Gridview，它使用 XML 文件运行。当我尝试通过 Gridiview 更新/删除一行时，XML 文件中的所有数据都会被删除。当我插入新行时，挂起的数据将被新行替换。我可以就我做错了什么得到一些指导吗？我提供了我的 xml 文件和用于编辑 GridView 的四种方法。

XML：

<root>
    <pos>
        <partNumbers>
            <partid>0</partid>
            <partnumber>796542</partnumber>
        </partNumbers>
        <partNumbers>
            <partid>1</partid>
            <partnumber>225614</partnumber>
        </partNumbers>
        <partNumbers>
            <partid>2</partid>
            <partnumber>123457</partnumber>
        </partNumbers>
    </pos>
</root>

源代码-C#-:

//Bind Data
    protected void BindGridView()
    {
        DataSet dsgvPartNumber = new DataSet();
        dsgvPartNumber.ReadXml(Server.MapPath("~/xml/storeUserInfo.xml"));
        gvPartNumber.DataSource = dsgvPartNumber.Tables["partNumbers"];
        gvPartNumber.DataBind();
        gvPartNumber.ShowFooter = true;
    }
    //Delete
    protected void gvPartNumber_RowDeleting(object sender, GridViewDeleteEventArgs e)
    {
        BindGridView();
        DataTable dsgvPartNumberDelete = (DataTable)gvPartNumber.DataSource;
        dsgvPartNumberDelete.Rows[gvPartNumber.Rows[e.RowIndex].DataItemIndex].Delete();
        dsgvPartNumberDelete.WriteXml(Server.MapPath("~/xml/storeUserInfo.xml"));
        BindGridView();

    }

//Update GridView
    protected void gvPartNumber_RowUpdating(object sender, GridViewUpdateEventArgs e)
    {
        int index = gvPartNumber.Rows[e.RowIndex].DataItemIndex;
        string partId = ((TextBox)gvPartNumber.Rows[e.RowIndex].FindControl("txtPartID")).Text;
        string partNumber = ((TextBox)gvPartNumber.Rows[e.RowIndex].FindControl("txtPartNumber")).Text;
        gvPartNumber.EditIndex = -1;
        BindGridView();
        DataTable dtUpdateXMLFile = (DataTable)gvPartNumber.DataSource;
        dtUpdateXMLFile.Rows[index]["partid"] = partId;
        dtUpdateXMLFile.Rows[index]["partnumber"] = partNumber;
        dtUpdateXMLFile.WriteXml(Server.MapPath("~/xml/storeUserInfo.xml"));
        BindGridView();

    }

//Insert New Row
    protected void gvPartNumber_RowCommand(object sender, GridViewCommandEventArgs e)
    {

        if (e.CommandName == "insertXMLData")
        {
            string partid = ((TextBox)gvPartNumber.FooterRow.FindControl("txtPartIDInsert")).Text;
            string partnumber = ((TextBox)gvPartNumber.FooterRow.FindControl("txtPartNumberInsert")).Text;
            BindGridView();
            DataTable dtXMLInsert = (DataTable)gvPartNumber.DataSource;
            DataRow drInsert = dtXMLInsert.NewRow();
            drInsert["partid"] = partid;
            drInsert["partnumber"] = partnumber;
            dtXMLInsert.Rows.Add(drInsert);
            dtXMLInsert.WriteXml(Server.MapPath("~/xml/storeUserInfo.xml"));
            BindGridView();
        }
    }

Answer 1

我可以看到您正在将数据表保存到错误的 xml 文件中：

    DataTable dtUpdateXMLFile = (DataTable)gvPartNumber.DataSource;
    dtUpdateXMLFile.Rows[index]["partid"] = partId;
    dtUpdateXMLFile.Rows[index]["partnumber"] = partNumber;
    dtUpdateXMLFile.WriteXml(Server.MapPath("~/xml/storeUserInfo.xml"));

请记住，此表仅来自您的 xml 文件的一部分（还有另一个表 pos）。实际上你必须保存数据集，而不是这个表。首先将表更新为数据集，然后保存。您的方法可能如下所示：

//Delete
protected void gvPartNumber_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
    BindGridView();
    DataSet dsgvPartNumber = new DataSet();
    dsgvPartNumber.ReadXml(Server.MapPath("~/xml/storeUserInfo.xml"));
    dsgvPartNumber.Tables["partNumbers"].Rows[gvPartNumber.Rows[e.RowIndex].DataItemIndex].Delete();
    dsgvPartNumber.WriteXml(Server.MapPath("~/xml/storeUserInfo.xml"));
    BindGridView();

}

//Update GridView
protected void gvPartNumber_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
    int index = gvPartNumber.Rows[e.RowIndex].DataItemIndex;
    string partId = ((TextBox)gvPartNumber.Rows[e.RowIndex].FindControl("txtPartID")).Text;
    string partNumber = ((TextBox)gvPartNumber.Rows[e.RowIndex].FindControl("txtPartNumber")).Text;
    gvPartNumber.EditIndex = -1;
    BindGridView();

    DataSet dsgvPartNumber = new DataSet();
    dsgvPartNumber.ReadXml(Server.MapPath("~/xml/storeUserInfo.xml"));
    dsgvPartNumber.Tables["partNumbers"].Rows[index]["partid"] = partId;
    dsgvPartNumber.Tables["partNumbers"].Rows[index]["partnumber"] = partNumber;
    dsgvPartNumber.WriteXml(Server.MapPath("~/xml/storeUserInfo.xml"));
    BindGridView();

}

//Insert New Row
protected void gvPartNumber_RowCommand(object sender, GridViewCommandEventArgs e)
{

    if (e.CommandName == "insertXMLData")
    {
        string partid = ((TextBox)gvPartNumber.FooterRow.FindControl("txtPartIDInsert")).Text;
        string partnumber = ((TextBox)gvPartNumber.FooterRow.FindControl("txtPartNumberInsert")).Text;
        BindGridView();
        DataTable dtXMLInsert = (DataTable)gvPartNumber.DataSource;

        DataSet dsgvPartNumber = new DataSet();
        dsgvPartNumber.ReadXml(Server.MapPath("~/xml/storeUserInfo.xml"));
        DataRow drInsert = dsgvPartNumber.Tables["partNumbers"].NewRow(); 
        drInsert["partid"] = partid;
        drInsert["partnumber"] = partnumber;
        dsgvPartNumber.Tables["partNumbers"].Rows.Add(drInsert);
        dsgvPartNumber.WriteXml(Server.MapPath("~/xml/storeUserInfo.xml"));
        BindGridView();

    }
}