On cc1:XDataGrid data load, shows Unable to cast object error

Question

User1914091530 posted

Below Aspx page

                                                        <asp:TemplateColumn HeaderText="Corp A/C" ItemStyle-Height="50px">
                                                            <ItemTemplate>
                                                                <asp:Label runat="server" style="word-wrap:break-word;" Text='<%# DataBinder.Eval(Container, "DataItem.AccountNo") %>'
                                                                    ID="Corpaccount">
                                                                </asp:Label>
                                                                
                                                             </ItemTemplate>
                                                            <HeaderStyle width="10%"></HeaderStyle>
                                                        </asp:TemplateColumn>
                                                        <asp:TemplateColumn HeaderText="Corp Name">
                                                            <ItemTemplate>
                                                                <asp:Label runat="server" style="word-wrap:break-word;" Text='<%# DataBinder.Eval(Container, "DataItem.CorporateName") %>'
                                                                    ID="CorpName">
                                                                </asp:Label>
                                                            
                                                             </ItemTemplate>
                                                            <HeaderStyle width="4%"></HeaderStyle>
                                                        </asp:TemplateColumn>
                                                        <asp:ButtonColumn DataTextField="FileName" HeaderText="NON-MOL File" CommandName="FileName" >
                                                            <HeaderStyle width="15%" />
                                                        </asp:ButtonColumn>

shows below error on data load

Unable to cast object of type 'System.Web.UI.LiteralControl' to type 'System.Web.UI.WebControls.LinkButton'.

But below aspx page

                                                        <asp:TemplateColumn HeaderText="Corp A/C" ItemStyle-Height="50px">
                                                            <ItemTemplate>
                                                                <asp:Label runat="server" style="word-wrap:break-word;" Text='<%# DataBinder.Eval(Container, "DataItem.AccountNo") %>'
                                                                    ID="Corpaccount">
                                                                </asp:Label>
                                                                
                                                             </ItemTemplate>
                                                            <HeaderStyle width="10%"></HeaderStyle>
                                                        </asp:TemplateColumn>

                                                        <asp:ButtonColumn DataTextField="FileName" HeaderText="NON-MOL File" CommandName="FileName" >
                                                            <HeaderStyle width="15%" />
                                                        </asp:ButtonColumn>
                                                        <asp:TemplateColumn HeaderText="Corp Name">
                                                            <ItemTemplate>
                                                                <asp:Label runat="server" style="word-wrap:break-word;" Text='<%# DataBinder.Eval(Container, "DataItem.CorporateName") %>'
                                                                    ID="CorpName">
                                                                </asp:Label>                                                            
                                                             </ItemTemplate>
                                                            <HeaderStyle width="4%"></HeaderStyle>
                                                        </asp:TemplateColumn>

has no error on data load

Please help?

Answer 1

User-1174608757 posted

Hi shijostephen,

According to your description, the error is clearly telling you that you cannot convert an object of type A to an object of type B.This error happens in your code behind. So I hope you could post more detail about your codes in code behind.

Else,simply look at this error message, I think you are trying to convert the label control to  LinkButton in code behind.Error may happen in some codes as 

 LinkButton lblCountry = (LinkButton)row.Cells[4].Controls[0];

Best  Regards

Wei Zhang

Answer 2

User1914091530 posted

But below aspx page

                                                        <asp:TemplateColumn HeaderText="Corp A/C" ItemStyle-Height="50px">
                                                            <ItemTemplate>
                                                                <asp:Label runat="server" style="word-wrap:break-word;" Text='<%# DataBinder.Eval(Container, "DataItem.AccountNo") %>'
                                                                    ID="Corpaccount">
                                                                </asp:Label>
                                                                
                                                             </ItemTemplate>
                                                            <HeaderStyle width="10%"></HeaderStyle>
                                                        </asp:TemplateColumn>

                                                        <asp:ButtonColumn DataTextField="FileName" HeaderText="NON-MOL File" CommandName="FileName" >
                                                            <HeaderStyle width="15%" />
                                                        </asp:ButtonColumn>
                                                        <asp:TemplateColumn HeaderText="Corp Name">
                                                            <ItemTemplate>
                                                                <asp:Label runat="server" style="word-wrap:break-word;" Text='<%# DataBinder.Eval(Container, "DataItem.CorporateName") %>'
                                                                    ID="CorpName">
                                                                </asp:Label>                                                            
                                                             </ItemTemplate>
                                                            <HeaderStyle width="4%"></HeaderStyle>
                                                        </asp:TemplateColumn>

has no error on data load, Here in this I have just changed the position of "Corp Name" Template Column.

Please tell how this error could happen for simply changing the grid column position..

Answer 3

User-1174608757 posted

Hi shijiostephen,

Could you please post the code behind? I don't think the error happens just because changing the position of column.I think there exists  operations on the foreground page in the code behind. 

Best Regards

Wei Zhang

Answer 4

User1914091530 posted

It was error in the ItemDataBound event

    protected void grdSalaryPostCutOffQueue_ItemDataBound(object sender, DataGridItemEventArgs e)
    {
        try
        {
            if ((e.Item.ItemType == ListItemType.AlternatingItem) || (e.Item.ItemType == ListItemType.Item))
            {
                System.Web.UI.WebControls.LinkButton btnColumn = (System.Web.UI.WebControls.LinkButton)e.Item.Cells[3].Controls[0];

Thanks