Overriding RenderItem() for CheckBoxList is not working properly RSS

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  e.zer0

  Member

  4 Points

  66 Posts

  Overriding RenderItem() for CheckBoxList is not working properly

  Aug 21, 2008 08:39 PM|LINK

  This is the code I have:

  public class MyCheckBoxList : CheckBoxList
  
  
  {
          #region Methods
          public void BindCollection(object o, string dataTextField, string dataValueField)
          {
              try
              {
                  if (this.DataSource != null)
                      this.DataSource = null;
  
  
                  this.DataSource = o;
                  this.DataTextField = dataTextField;
                  this.DataValueField = dataValueField;
                  this.DataBind();
              }
              catch
              {
                  this.DataSource = null;
              }
          }
          protected override void RenderItem(ListItemType itemType, int repeatIndex, RepeatInfo repeatInfo, HtmlTextWriter writer)
          {
              CheckBox chk = new CheckBox();
              chk.Page = this.Page;
              chk.ID = this.ClientID + "_" + repeatIndex.ToString();
              chk.Text = this.Items[repeatIndex].Text;
              chk.Attributes["value"] = this.Items[repeatIndex].Value;
              chk.Checked = this.Items[repeatIndex].Selected;
              chk.CssClass = CssClass;
              chk.TextAlign = this.TextAlign;
  
  
              chk.RenderControl(writer);
          }
          #endregion
      }
  }

  The check boxes rener fine but after a postback none of the Items come back as selected even thou I selected some....they simply just go back to unchecked and hence I can never tell which ones were selected.  Why is this happening?

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  dannylloyd

  Member

  2 Points

  2 Posts

  Re: Overriding RenderItem() for CheckBoxList is not working properly

  Jan 08, 2013 03:16 PM|LINK

  I'm sure this user is long gone, but for anyone who stumbles upon this, as I did, here is the solution I used.

  http://sebastienlachance.com/blog/revisited-going-back-to-aspnet-webforms-and-a-lot-of-pain-with-the-checkboxlist

  What is happening is that there isn't a uniqueID as well as a ClientID, the code below is what I used to create a custom formmatted checkbox with a label wrapped around it. (This is the format that Twitter bootstrap uses, that's why I used it).

  Dim item = MyBase.Items(repeatIndex)
              Dim title = item.Attributes("title")
              writer.Write(String.Format("<label title=""{0}"" class=""checkbox"">", title))
              writer.WriteBeginTag("input")
              writer.WriteAttribute("type", "checkbox")
              writer.WriteAttribute("name", UniqueID + Me.IdSeparator + repeatIndex.ToString(NumberFormatInfo.InvariantInfo))
              writer.WriteAttribute("id", ClientID + Me.ClientIDSeparator + repeatIndex.ToString(NumberFormatInfo.InvariantInfo))
              writer.WriteAttribute("value", item.Value)
  
              If item.Selected Then
                  writer.WriteAttribute("checked", "checked")
              End If
  
              Dim attrs As System.Web.UI.AttributeCollection = item.Attributes
              For Each key As String In attrs.Keys
                  writer.WriteAttribute(key, attrs(key))
              Next
  
              writer.Write(">")
              writer.Write(item.Text)
              writer.WriteEndTag("input")
              writer.WriteEndTag("label")

  • Edited by dannylloyd on Apr 02, 2013 05:25 PM
  • Edited by dannylloyd on Apr 02, 2013 05:26 PM
  • Edited by dannylloyd on Apr 02, 2013 05:27 PM
  • Edited by dannylloyd on Apr 02, 2013 05:28 PM