在Gridview DataBound中显示基于varchar列的CheckBox

SQL Server table structure:

SQL Server表结构：

ChapName        varchar(200)
Status          varchar(1)

Requirement:

需求：

I want to display checkbox in an ASP.NET gridview from Visual Studio 2010 if the value of status column is T, let it be checked and unchecked otherwise. but it shows only textbox.
如果status列的值为T，我想在Visual Studio 2010的ASP.NET网格视图中显示复选框，否则请检查并取消选中。但它只显示文本框。
I have tried <asp:templatefield> and <asp:itemtemplate> but it throws error if I try to bind this checkbox.
我尝试过和，但如果我尝试绑定此复选框，则会抛出错误。：itemtemplate> ：templatefield>
any sample code is required as I am beginner in this field.
因为我是这个领域的初学者，所以需要任何示例代码。

The code I tried:

我试过的代码：

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
            CheckBox c = (CheckBox)GridView1.FindControl("ChkStatus");
            TextBox TB = (TextBox)GridView1.FindControl("Status");

        //Response.Write(TB.Text);
            if (TB.Text == "T")
            {
                c.Checked = true;
            }
            else
            {
                c.Checked = false;
            }
    }

The error I got

我得到的错误

Object reference not set to an instance of an object.

你调用的对象是空的。

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

描述：执行当前Web请求期间发生未处理的异常。请查看堆栈跟踪以获取有关错误及其源自代码的位置的更多信息。

Exception Details:
System.NullReferenceException: Object reference not set to an instance of an object.

异常详细信息：System.NullReferenceException：未将对象引用设置为对象的实例。

Aspx markup:

Aspx标记：

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" 
              DataKeyNames="Comp,QTypeCode" DataSourceID="SDS_QType_Edit" 
              BackColor="White" BorderColor="#DEDFDE" BorderStyle="None" 
              BorderWidth="1px" 
              CellPadding="4" ForeColor="Black" GridLines="Vertical" 
              AllowPaging="True" AllowSorting="True" 
              onselectedindexchanged="GridView1_SelectedIndexChanged" 
              onrowdatabound="GridView1_RowDataBound">
    <AlternatingRowStyle BackColor="White" />
    <Columns>
        <asp:CommandField ShowEditButton="True" ShowSelectButton="True" />
        <asp:BoundField DataField="QTypeCode" HeaderText="QTypeCode" 
                        SortExpression="QTypeCode" InsertVisible="False" 
                        ReadOnly="True" />
        <asp:BoundField DataField="Descr" HeaderText="Descr" SortExpression="Descr" />
        <asp:CheckBoxField DataField="AnsReq" HeaderText="AnsReq" ReadOnly="True" 
                           SortExpression="AnsReq" />
        <asp:CheckBoxField DataField="OptionPrint" HeaderText="OptionPrint" 
                           ReadOnly="True" SortExpression="OptionPrint" />
        <asp:BoundField DataField="Status" HeaderText="Status" 
                        SortExpression="Status" />
        <asp:BoundField DataField="TransDate" HeaderText="TransDate" 
                        SortExpression="TransDate" />
        <asp:BoundField DataField="UserName" HeaderText="UserName" 
                        SortExpression="UserName" />
        <asp:TemplateField HeaderText="Check Box" >
            <ItemTemplate>
                <asp:CheckBox ID ="ChkStatus" Text="text" runat="server" />
            </ItemTemplate>
        </asp:TemplateField>
     </Columns>
     <EditRowStyle Wrap="False" />
     <EmptyDataRowStyle Wrap="False" />
     <FooterStyle BackColor="#CCCC99" />
     <HeaderStyle Wrap="False" BackColor="#6B696B" Font-Bold="True" ForeColor="White" />
     <PagerStyle BackColor="#F7F7DE" ForeColor="Black" HorizontalAlign="Right" />
     <RowStyle Wrap="False" BackColor="#F7F7DE" />
     <SelectedRowStyle BackColor="#CE5D5A" Font-Bold="True" ForeColor="White" 
                       Wrap="False" />
     <SortedAscendingCellStyle BackColor="#FBFBF2" />
     <SortedAscendingHeaderStyle BackColor="#848384" />
     <SortedDescendingCellStyle BackColor="#EAEAD3" />
     <SortedDescendingHeaderStyle BackColor="#575357" />
</asp:GridView>

1 个解决方案

#1

Assume you have grid defined as below on asmx

假设您在asmx上定义了如下网格

<asp:GridView ID="GridView1" runat="server" 
    onrowdatabound="GridView1_RowDataBound" AutoGenerateColumns="False">
    <Columns>
        <asp:BoundField DataField="ChapName" HeaderText="ChapName" />
        <asp:TemplateField HeaderText="Status" Visible ="false">
            <ItemTemplate>
                <asp:Label ID="Status" runat="server" Text='<%# Bind("Status") %>'></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="Check Box" >
        <ItemTemplate>
            <asp:CheckBox ID ="ChkStatus" Text="text" runat="server" />
        </ItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>

on Row Data Bound event you can find controls as below

在Row Data Bound事件上，您可以找到如下控件

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{

    CheckBox c = e.Row.FindControl("ChkStatus") as CheckBox;
    Label lbl = e.Row.FindControl("Status") as Label;
    if (c!= null && lbl != null )
    {
        c.Checked = (lbl.Text == "T");
    }

}

#1