Added CheckBoxAutoPostBack To TreeView Component RSS

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  gjsduarte

  Member

  20 Points

  6 Posts

  Added CheckBoxAutoPostBack To TreeView Component

  Nov 18, 2009 11:00 AM|LINK

  Hi,
  
  I changed the code for the TreeView Adapter in order to perform an optional autopostback when a checkbox is clicked.

  private void WriteNodeCheckbox(TreeView treeView, TreeNode item, HtmlTextWriter writer)
  		{
  			// Added inline div to style both input and label controls on mouse over
  			// The original TreeView renders <TD> tags as containers and applies the class to them,
  			// so this is the best way I found to replicate that behavoiur
  			writer.WriteBeginTag("span");
  			// Added OnHover Method call
  			WriteNodeHoverBehaviour(writer);
  			writer.Write(HtmlTextWriter.TagRightChar);
  
  
  			writer.WriteBeginTag("input");
  			writer.WriteAttribute("type", "checkbox");
  			writer.WriteAttribute("id", treeView.ClientID + "n" + _checkboxIndex.ToString() + "CheckBox");
  			writer.WriteAttribute("name", treeView.UniqueID + "n" + _checkboxIndex.ToString() + "CheckBox");
  			if (!String.IsNullOrEmpty(treeView.Attributes["OnClientClickedCheckbox"]))
  			{
                  //Added functionality to add an AutoPostBack when the checkbox is clicked
                  //New code ->>
  			    string postbackJava = "";
                  if (treeView.Attributes["CheckBoxAutoPostBack"] == "True")
                  {
                      const string codePrefix = "c";
                      postbackJava = Page.ClientScript.GetPostBackClientHyperlink(treeView,
                                                                                  codePrefix +
                                                                                  (Page.Server.HtmlEncode(item.ValuePath)).Replace("/", "\\"), true);
                  }
                  writer.WriteAttribute("onclick", treeView.Attributes["OnClientClickedCheckbox"] + "; " + postbackJava);
                  //End of new code
                  //Disabled code ->>
                  //writer.WriteAttribute("onclick", treeView.Attributes["OnClientClickedCheckbox"]);
                  //End <<-
  			}
  
  
  		    if (item.Checked)
  			{
  				writer.WriteAttribute("checked", "checked");
  			}
  			writer.Write(HtmlTextWriter.SelfClosingTagEnd);
              //Added functionality to add image to checkbox node
              //New code ->>
              WriteNodeImage(treeView, item, writer);
              //End <<-
  			if (!String.IsNullOrEmpty(item.Text))
  			{
  				writer.WriteLine();
  				writer.WriteBeginTag("label");
  				writer.WriteAttribute("for", treeView.ClientID + "n" + _checkboxIndex.ToString() + "CheckBox");
  				writer.Write(HtmlTextWriter.TagRightChar);
  				writer.Write(item.Text);
  				writer.WriteEndTag("label");
  			}
  
  
  			_checkboxIndex++;
  
  
  			// Close Span
  			writer.WriteEndTag("span");
  			//
  		}

  
  With this you just add the boolean attribute CheckBoxAutoPostBack to control declaration:

  <asp:TreeView ID="MyTreeView" runat="server" OnClientClickedCheckbox="CascadeCheckmarks(event)"
      OnTreeNodeCheckChanged="OnCheckChanged" OnAdaptedTreeNodeCheckChanged="OnCheckChanged"
      CssSelectorClass="SimpleEntertainmentTreeView" CheckBoxAutoPostBack="True" ShowCheckBoxes="All">
  </asp:TreeView>

  
  
  

  Treeview checkbox AutoPostBack

  Guilherme Duarte
  Systems Administrator & .NET Developer