ListView Select Button have to be clicked twice to function for custom datasource RSS

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  Cheng Bao

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  145 Posts

  ListView Select Button have to be clicked twice to function for custom datasource

  Jan 03, 2013 06:27 PM|LINK

  I have a list view which bind with custom data source by using ListView.DataSource Property. However, if so, the select button will not work properly. First click on select button in a desired row, there is no changes on post back pages. Another click on any select button, the row that first selected will be selected. That's frustrating.

  Code:

  <form id="form1" runat="server" >
      
      
      <asp:ListView ID="lvTest" runat="server"
          onselectedindexchanging="lvTest_SelectedIndexChanging">
          <LayoutTemplate>
              <table>
                  <tr runat="server" id="itemPlaceholder"></tr>
              </table>
          </LayoutTemplate>
          <ItemTemplate>
              <tr runat="server">
                  <td><%# Container.DataItem.ToString() %></td>
                  <td><asp:LinkButton ID="LinkButton1" runat="server" CommandName="Select">Select</asp:LinkButton></td>
              </tr>
          </ItemTemplate>
          <SelectedItemTemplate>
              <tr id="Tr1" runat="server">
                  <td><%# Container.DataItem.ToString() %></td>
                  <td>Selected</td>
              </tr>
          </SelectedItemTemplate>
      </asp:ListView>
      
      </form>

  Code Behind

  public partial class _Default : Page
  {
  
      
      
      void Page_Load(object sender, EventArgs e)
      {
          BindData();
      }
  
      void BindData()
      {
          int[] list = new int[] {1,2,3,4,5};
          lvTest.DataSource = list;
          lvTest.DataBind();
      }
  
      protected void lvTest_SelectedIndexChanging(object sender, ListViewSelectEventArgs e)
      {
          lvTest.SelectedIndex = e.NewSelectedIndex;
      }
  }

  
  
  
  

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  msmk

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  180 Posts

  Re: ListView Select Button have to be clicked twice to function for custom datasource

  Jan 03, 2013 06:31 PM|LINK

  This is because selectedIndexChanging is handled when the select button is clicked but before the control handles the select. There is therefore no selectedIndex yet! But by the second click, there is a selectedIndex - the one from last click. It did not change yet because the new select was not yet handled.

  Change the method to selectedIndexChanged and you should be good.

  • Edited by msmk on Jan 03, 2013 06:32 PM
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  Cheng Bao

  Member

  245 Points

  145 Posts

  Re: ListView Select Button have to be clicked twice to function for custom datasource

  Jan 03, 2013 06:42 PM|LINK

  well, ListView_SelectedIndexChanged doesn't have ListViewSelectEventArgs as parameter, it takes EventArgs as event parameter, which doesn't have any NewSelectedIndex property.

  Also, I have find that e.NewSelectedIndex indeed has correct value during selectedIndexChanging events.

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  Madhu1234

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  Re: ListView Select Button have to be clicked twice to function for custom datasource

  Jan 03, 2013 06:58 PM|LINK

  Try to bind your listview in (!IsPostBack) in Page load event.

• • Reply
  

  Cheng Bao

  Member

  245 Points

  145 Posts

  Re: ListView Select Button have to be clicked twice to function for custom datasource

  Jan 03, 2013 06:59 PM|LINK

  Ok, I remember I met similar problem before, then I search my own posts, I find I already got a solution before

  http://forums.asp.net/t/1798672.aspx/1?DataPager+bug+

  I need to bind data in Page_PreRender event. I believe it is a bug.

• • Reply
  

  Cheng Bao

  Member

  245 Points

  145 Posts

  Re: ListView Select Button have to be clicked twice to function for custom datasource

  Jan 03, 2013 07:00 PM|LINK

  Madhu1234

  Try to bind your listview in (!IsPostBack) in Page load event.

  This won't work. In fact, my original code has (!IsPostBack). I google some solution, some one said to Data Bind every time in page_load will work, but it is not for me

• • Reply
  

  Madhu1234

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  Re: ListView Select Button have to be clicked twice to function for custom datasource

  Jan 03, 2013 07:15 PM|LINK

  Try to get the selectedindex value like this..

  protected void lvTest_SelectedIndexChanged(object sender,System.Web.UI.WebControls.DataListItemEventArgs e)
  {

     lvTest.SelectedIndex=e.Item.ItemIndex;

  }

• • Reply
  

  Cheng Bao

  Member

  245 Points

  145 Posts

  Re: ListView Select Button have to be clicked twice to function for custom datasource

  Jan 03, 2013 07:30 PM|LINK

  Madhu1234

  Try to get the selectedindex value like this..

  protected void lvTest_SelectedIndexChanged(object sender,System.Web.UI.WebControls.DataListItemEventArgs e)
  {

     lvTest.SelectedIndex=e.Item.ItemIndex;

  }

  You will get compliation error

  Compiler Error Message: CS0123: No overload for 'lvTest_SelectedIndexChanged' matches delegate 'System.EventHandler'

  Even force cast EventArgs to DataListItemEventArgs will fail

  protected void lvTest_SelectedIndexChanged(object sender, EventArgs e)
      {
          var e2 = (System.Web.UI.WebControls.DataListItemEventArgs) e;
  
      }

  
  
  

  Unable to cast object of type 'System.EventArgs' to type 'System.Web.UI.WebControls.DataListItemEventArgs'.

  the args is indeed System.EventArgs, nothing else.

• • Reply
  

  Madhu1234

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  Re: ListView Select Button have to be clicked twice to function for custom datasource

  Jan 03, 2013 07:40 PM|LINK

  Sorry I mistook it as Datalist instead of listview....:(

  will now check the solution for listview..

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  Madhu1234

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  Re: ListView Select Button have to be clicked twice to function for custom datasource

  Jan 03, 2013 07:46 PM|LINK

  Check this example for How to make a row selectable in listview...

  http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.listview.selectedindexchanged(v=vs.90).aspx

  Hope this helps you.