Question

我想从GridView中删除选定的行。为此我写了下面的代码，但我得到了一个例外：

System.Web.dll中出现未处理的“System.StackOverflowException”类型异常

这是我的aspx.page：

    <asp:gridview ID="Gridview1" runat="server" ShowFooter="true" 
            onrowcommand="Gridview1_RowCommand"  AutoGenerateColumns="false" 
            CellSpacing="0" CellPadding="0" Font-Bold="false" 
            onrowdeleting="Gridview1_RowDeleting">
        <Columns>
      <asp:TemplateField HeaderText="Select" ControlStyle-Width="50px" HeaderStyle-Font-Bold="false" ControlStyle-Font-Bold="false">
     <ItemTemplate>         
         <asp:CheckBox ID="chkSelect" runat="server" Width="80px"/>
     </ItemTemplate>
   </asp:TemplateField>
        <asp:TemplateField HeaderText="Header 1" HeaderStyle-Font-Bold="false" ControlStyle-Font-Bold="false">
            <ItemTemplate>
                <asp:TextBox ID="TextBox1" runat="server" Width="70px"></asp:TextBox>
            </ItemTemplate>            
            <FooterTemplate>
                <asp:Label ID="lblTotal" runat="server" Text="Total" Font-Bold="true"></asp:Label>
            </FooterTemplate>            
        </asp:TemplateField>
        <asp:TemplateField HeaderText="Header 2"  HeaderStyle-Font-Bold="false" ControlStyle-Font-Bold="false">
            <ItemTemplate>
                <asp:TextBox ID="TextBox2" Width="70px" runat="server" class="calculate" onchange="calculate()"></asp:TextBox>
            </ItemTemplate>            
            <FooterTemplate>
                <asp:TextBox ID="total" runat="server" Width="70px"></asp:TextBox>
            </FooterTemplate>  

        </asp:TemplateField>
        <asp:TemplateField HeaderText="Header 3" HeaderStyle-Font-Bold="false" ControlStyle-Font-Bold="false">
            <ItemTemplate>
                 <asp:TextBox ID="TextBox3" Width="70px" runat="server" ></asp:TextBox>
            </ItemTemplate>
            <FooterStyle HorizontalAlign="Right" />
            <FooterTemplate>
             <asp:Button ID="ButtonAdd" runat="server" Text="Add New Row" CommandName="AddNewRow" />
            <asp:Button  ID="btnDelete" runat="server" CommandName="DeleteRow" Text="Delete"         
            OnClientClick="return DeleteConfirmation();"/> 
            </FooterTemplate>
        </asp:TemplateField>
        </Columns>
</asp:gridview>

以下是aspx页面背后的代码：

     public partial class _Default : System.Web.UI.Page
    {
     protected void Page_Load(object sender, EventArgs e)
     {
        if (!Page.IsPostBack)
        {
            SetInitialRow();
        }

    }

    private void SetInitialRow()
    {
        DataTable dt = new DataTable();
        DataRow dr = null;
        dt.Columns.Add(new DataColumn("RowNumber", typeof(string)));
        dt.Columns.Add(new DataColumn("Column1", typeof(string)));
        dt.Columns.Add(new DataColumn("Column2", typeof(string)));
        dt.Columns.Add(new DataColumn("Column3", typeof(string)));
        dr = dt.NewRow();
        dr["RowNumber"] = 1;
        dr["Column1"] = string.Empty;
        dr["Column2"] = string.Empty;
        dr["Column3"] = string.Empty;
        dt.Rows.Add(dr);
        //dr = dt.NewRow();

        //Store the DataTable in ViewState
        ViewState["CurrentTable"] = dt;

        Gridview1.DataSource = dt;
        Gridview1.DataBind();
    }

    private void AddNewRowToGrid()
    {
        int rowIndex = 0;

        if (ViewState["CurrentTable"] != null)
        {
            DataTable dtCurrentTable = (DataTable)ViewState["CurrentTable"];
            DataRow drCurrentRow = null;
            if (dtCurrentTable.Rows.Count > 0)
            {
                for (int i = 1; i <= dtCurrentTable.Rows.Count; i++)
                {
                    //extract the TextBox values
                    TextBox box1 =  (TextBox)Gridview1.Rows[rowIndex].Cells[1].FindControl("TextBox1");
                    TextBox box2 = (TextBox)Gridview1.Rows[rowIndex].Cells[2].FindControl("TextBox2");
                    TextBox box3 = (TextBox)Gridview1.Rows[rowIndex].Cells[3].FindControl("TextBox3");

                    drCurrentRow = dtCurrentTable.NewRow();
                    drCurrentRow["RowNumber"] = i + 1;
                    drCurrentRow["Column1"] = box1.Text;
                    drCurrentRow["Column2"] = box2.Text;
                    drCurrentRow["Column3"] = box3.Text;

                    rowIndex++;
                }
                //add new row to DataTable
                dtCurrentTable.Rows.Add(drCurrentRow);
                //Store the current data to ViewState
                ViewState["CurrentTable"] = dtCurrentTable;

                //Rebind the Grid with the current data
                Gridview1.DataSource = dtCurrentTable;
                Gridview1.DataBind();
            }
        }
        else
        {
            Response.Write("ViewState is null");
        }
        //Set Previous Data on Postbacks
        SetPreviousData();
    }

    private void SetPreviousData()
    {
        int rowIndex = 0;
        if (ViewState["CurrentTable"] != null)
        {
            DataTable dt = (DataTable)ViewState["CurrentTable"];
            if (dt.Rows.Count > 0)
            {
                for (int i = 1; i < dt.Rows.Count; i++)
                {
                    TextBox box1 = (TextBox)Gridview1.Rows[rowIndex].Cells[1].FindControl("TextBox1");
                    TextBox box2 = (TextBox)Gridview1.Rows[rowIndex].Cells[2].FindControl("TextBox2");
                    TextBox box3 = (TextBox)Gridview1.Rows[rowIndex].Cells[3].FindControl("TextBox3");

                    box1.Text = dt.Rows[i]["Column1"].ToString();
                    box2.Text = dt.Rows[i]["Column2"].ToString();
                    box3.Text = dt.Rows[i]["Column3"].ToString();

                    rowIndex++;

                }
            }
        }
    }
    protected void Gridview1_RowCommand(object sender, GridViewCommandEventArgs e)
    {
        if (e.CommandName == "AddNewRow")
        {
            AddNewRowToGrid();          
        }
        if (e.CommandName == "DeleteRow")
        {
      for (int i = 0; i < Gridview1.Rows.Count; i++)
            {
                CheckBox chkDelete = (CheckBox)
                   Gridview1.Rows[i].Cells[0].FindControl("chkSelect");
                if (chkDelete != null)
                {
                    if (chkDelete.Checked)
                    {
                        //strID = GridView1.Rows[i].Cells[1].Text;
                        //idCollection.Add(strID);
                        Gridview1.DeleteRow(i);
                    }
                }
            }
        }
        Gridview1.DataBind();
    }
       protected void Gridview1_RowDeleting(object sender, GridViewDeleteEventArgs e)
       {
           for (int i = 0; i < Gridview1.Rows.Count; i++)
            {
                CheckBox chkDelete = (CheckBox)
                   Gridview1.Rows[i].Cells[0].FindControl("chkSelect");
                if (chkDelete != null)
                {
                    if (chkDelete.Checked)
                    {
                        //strID = GridView1.Rows[i].Cells[1].Text;
                        //idCollection.Add(strID);
                        Gridview1.DeleteRow(i);
                    }
                }
            }
           Gridview1.DataBind();       
    }
}

Answer 1

我认为您不需要在代码中实现RowDeleting事件。 RowDeleting事件就是告诉程序一行将被删除。

在您的示例中，RowDeleting事件正在调用DeleteRow方法，这将导致RowDeleting事件被触发，然后圆圈将再次发生。当计算机没有其他选项导致StackOverflowException并结束您的程序时，此圈子最终会结束。

从GridView中删除行时获取异常

1 个答案: