我在gridview中从数据库中提取数据，在那里我给出了一个链接按钮“编辑”来编辑该行的数据。但是在编辑时，我的gridview的一列（YEAR）变为下拉列表。从数据库中获取数据时，列“年”由标签组成，在编辑模式下，它将更改为下拉列表。此外，我添加了一个条件，使链接按钮根据标签“年”的值显示/消失。当我编辑特定行时，它会抛出一个错误，因为只要调用edit命令，它就会将列转换为下拉列表，但row_databound会搜索label。它显示“对象未设置为实例.....”PLease帮助
Aspx
<asp:GridView ID="gv1" runat="server" AutoGenerateColumns="False" BackColor="White" BorderColor="#3366CC" BorderStyle="None" BorderWidth="1px" CellPadding="4" DataSourceID="SqlDataSource2" OnRowDataBound="gv1_RowDataBound" OnRowUpdating="gv1_RowUpdating" DataKeyNames="tid" CssClass="auto-style1" Width="694px">
<Columns>
<asp:TemplateField HeaderText="Sr No">
<ItemTemplate>
<%#Container.DataItemIndex+1 %>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="tid" SortExpression="tid" Visible="false">
<ItemTemplate>
<asp:Label ID="lblID" runat="server" Text='<%# Bind("tid") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Title" SortExpression="title">
<EditItemTemplate>
<asp:TextBox ID="txtTitle1" runat="server" Text='<%# Bind("title") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="lblTitle" runat="server" Text='<%# Bind("title") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Category" SortExpression="category">
<ItemTemplate>
<asp:Label ID="lblCategory" runat="server" Text='<%# Bind("category") %>'></asp:Label></ItemTemplate>
<EditItemTemplate>
<asp:RadioButtonList ID="rbtnlist" runat="server"><asp:ListItem Text="Soft Skills"></asp:ListItem><asp:ListItem Text="Technical Skills"></asp:ListItem></asp:RadioButtonList>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Announced at" SortExpression="dt">
<ItemTemplate>
<asp:Label ID="lblDt" runat="server" Text='<%# Bind("dt", "{0:dd/MMM/yyyy HH:mm tt}") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Year" SortExpression="year">
<EditItemTemplate>
<asp:DropDownList ID="ddlyr" runat="server"></asp:DropDownList>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="lblyr" runat="server" Text='<%# Bind("year") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="User Id" SortExpression="userid">
<ItemTemplate>
<asp:Label ID="lblUid" runat="server" Text='<%# Bind("userid") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField ShowHeader="False">
<ItemTemplate>
<asp:LinkButton ID="btndel" runat="server" CausesValidation="False" CommandName="Delete" Text="Delete" OnClientClick="return isConfirm()" Visible="false"></asp:LinkButton>
<%--<asp:LinkButton ID="btnmail" runat="server" CausesValidation="False" OnClientClick="return isConfirm()" Text="Send Mail" Visible="false"></asp:LinkButton>--%>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField ShowHeader="False">
<EditItemTemplate>
<asp:LinkButton ID="btnupdte" runat="server" CausesValidation="True" CommandName="Update" Text="Update"></asp:LinkButton>
<asp:LinkButton ID="btncncl" runat="server" CausesValidation="False" CommandName="Cancel" Text="Cancel"></asp:LinkButton>
</EditItemTemplate>
<ItemTemplate>
<asp:LinkButton ID="btnedit" runat="server" CausesValidation="False" CommandName="Edit" Text="Edit" Visible="false"></asp:LinkButton>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField ShowHeader="false">
<ItemTemplate>
<asp:LinkButton ID="btnmail" runat="server" CausesValidation="False" OnClientClick="return isConfirm()" Text="Send Mail" Visible="false"></asp:LinkButton>
</ItemTemplate>
</asp:TemplateField>
</Columns>
<FooterStyle BackColor="#99CCCC" ForeColor="#003399" />
<HeaderStyle BackColor="#003399" Font-Bold="True" ForeColor="#CCCCFF" />
<PagerStyle ForeColor="#003399" HorizontalAlign="Left" BackColor="#99CCCC" />
<RowStyle BackColor="White" ForeColor="#003399" />
<SelectedRowStyle BackColor="#009999" Font-Bold="True" ForeColor="#CCFF99" />
<SortedAscendingCellStyle BackColor="#EDF6F6" />
<SortedAscendingHeaderStyle BackColor="#0D4AC4" />
<SortedDescendingCellStyle BackColor="#D6DFDF" />
<SortedDescendingHeaderStyle BackColor="#002876" />
</asp:GridView>
C＃
protected void gv1_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
Label lbly = (Label)e.Row.FindControl("lblyr");
if (lbly.Text == DateTime.Now.Year.ToString() || lbly.Text == ((DateTime.Now.Year)-1).ToString())
{
LinkButton btedt = (LinkButton)e.Row.FindControl("btnedit");
LinkButton btdel = (LinkButton)e.Row.FindControl("btndel");
LinkButton btsm = (LinkButton)e.Row.FindControl("btnmail");
btdel.Visible = true;
btedt.Visible = true;
btsm.Visible = true;
}
if ((e.Row.RowState & DataControlRowState.Edit) > 0) {
RadioButtonList rbtnlist = (RadioButtonList)e.Row.FindControl("rbtnlist");
DropDownList ddlist = (DropDownList)e.Row.FindControl("ddlyr");
for (int i = (DateTime.Now.Year); i >= ((DateTime.Now.Year)-1) ; i--)
{
ddlist.Items.Add(new ListItem(i.ToString(), i.ToString()));
}
ddlist.DataBind();
rbtnlist.DataBind();
}
}
}
答案 0 :(得分：0)
我假设您使用colum name＆＃34; Year＆＃34;将您的网格绑定到DataTable。尝试以下代码，其中dt指的是您的数据表：
protected void gv1_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
int rowno = e.Row.DataItemIndex;
//Suppose dt is DataTable to which you are binding your grid
//and year is the column name within this datatable
string year = Convert.ToString(dt.Rows[e.Row.DataItemIndex]["year"]);
if (year == DateTime.Now.Year.ToString() || year == ((DateTime.Now.Year) - 1).ToString())
{
LinkButton btedt = (LinkButton)e.Row.FindControl("btnedit");
LinkButton btdel = (LinkButton)e.Row.FindControl("btndel");
LinkButton btsm = (LinkButton)e.Row.FindControl("btnmail");
btdel.Visible = true;
btedt.Visible = true;
btsm.Visible = true;
}
if ((e.Row.RowState & DataControlRowState.Edit) > 0)
{
RadioButtonList rbtnlist = (RadioButtonList)e.Row.FindControl("rbtnlist");
DropDownList ddlist = (DropDownList)e.Row.FindControl("ddlyr");
for (int i = (DateTime.Now.Year); i >= ((DateTime.Now.Year) - 1); i--)
{
ddlist.Items.Add(new ListItem(i.ToString(), i.ToString()));
}
ddlist.DataBind();
rbtnlist.DataBind();
}
}