Create a custom dropdown in webpart property that loads values from a list

Question

I want to create a custom webpart property which will be a dropdown list. and i want to load values from a sharepoint list. So far i could only find a way to provide static values for list contents. Is there some way i can load the values from a sharepoint list?Any sort of help will be appreaciated

Thank you

   public enum channelList { Health, Wealth, Life };

   public channelList ChannelTypes;

   [WebBrowsable(true),
   WebDisplayName("Choose Channel Type"),
   WebDescription(""),
   Personalizable(PersonalizationScope.Shared),
   Category("Extended Settings"),
   DefaultValue("Select a Channel Type")]
   public channelList _ChannelTypes
   {
        get { return ChannelTypes; }
        set { ChannelTypes = value; }
   }

i want to provide values to enum ChannelList from a sharepoint list

Answer 1

Mallu,

This can be achieved by creating Editorpart for your custom web part.

1. Lets say the web part that we are building is RightNav.ascx
2. Create a .CS file under your web part (.ascx)

3. Full code of the EditorPart.cs is as follows

You may have to edit the code as per your requirements

class RightNavEditorPart : EditorPart
        {
            #region Properties
            public string ListId { get; set; }
            public string ListName { get; set; }
            RightNav ParentWebPart { get; set; }
            #endregion

            #region Controls
            public Label ListPrompt = new Label() { Text = "Right Nav Links" };
            public DropDownList ddlLists = new DropDownList() { Width = 175, ID = "ddlLists" };
            #endregion

            #region Apply and Sync Changes
            public override bool ApplyChanges()
            {
                bool returnValue = false;
                try
                {
                    EnsureChildControls();
                    ParentWebPart = WebPartToEdit as RightNav;
                    if (ParentWebPart != null)
                    {
                        ParentWebPart.ListId = GetListSelectedValue(ddlLists);
                        ParentWebPart.ListName = GetListSelectedText(ddlLists);
                        returnValue = true;
                    }
                }
                catch (Exception ex)
                {
                    //Logging.Log(ex);
                }
                return returnValue;
            }
            public override void SyncChanges()
            {
                EnsureChildControls();
                ParentWebPart = WebPartToEdit as RightNav;
                if (ParentWebPart != null)
                {
                    SetListSelectedText(ParentWebPart.ListName, "--Select List--", ddlLists);
                }
            }
            #endregion

            #region Methods
            private string GetListSelectedValue(DropDownList ddl)
            {
                string returnValue = string.Empty;
                if (ddl.SelectedIndex != 0)
                {
                    returnValue = ddl.SelectedValue;
                }
                return returnValue;
            }
            public string GetListSelectedText(DropDownList ddl)
            {
                string returnValue = string.Empty;
                if (ddl.SelectedIndex != 0)
                {
                    returnValue = ddl.SelectedItem.Text;
                }
                return returnValue;
            }
            private void SetListSelectedText(string text, string defaultValue, DropDownList ddl)
            {
                if (!string.IsNullOrEmpty(text))
                {
                    if (ddl.Items.FindByText(text) != null)
                    {
                        ddl.Items.FindByText(text).Selected = true;

                    }
                }
                else if (!string.IsNullOrEmpty(defaultValue))
                {
                    if (ddl.Items.FindByText(defaultValue) != null)
                    {
                        for (int i = 0; i < ddl.Items.Count; i++)
                        {
                            if (ddl.Items[i].Text == defaultValue)
                            {
                                ddl.SelectedIndex = i;
                                break;
                            }
                        }
                    }
                }
            }
            #endregion

            #region Control Overrides
            protected override void CreateChildControls()
            {
                base.CreateChildControls();
                this.ChromeType = PartChromeType.None;
                try
                {
                    Controls.Add(ListPrompt);
                    Controls.Add(ddlLists);
                    LoadWebLists();
                }
                catch (Exception ex)
                {
                    // Log(ex);
                }
            }
            protected override void RenderContents(HtmlTextWriter writer)
            {
                try
                {
                    writer.Write("<div class='ms-TPBody' id='SGRightNav-editorpart'>");
                    writer.Write("<table>");
                    writer.Write("<tr><td>");
                    writer.Write("<div class='UserSectionHead'>");
                    ListPrompt.RenderControl(writer);
                    writer.Write("</div>");
                    writer.Write("<div class='UserSectionBody'>");
                    writer.Write("<div class='UserControlGroup'>");
                    ddlLists.RenderControl(writer);
                    writer.Write("</div>");
                    writer.Write("</div>");
                    writer.Write("</td></tr>");
                    writer.Write("</table>");
                    writer.Write("</div>");
                }
                catch (Exception ex)
                {
                    //Logging.Log(ex);
                }
            }
            #endregion

            #region Data Loading Methods
            private void LoadWebLists()
            {
                try
                {
                    //SPSecurity.RunWithElevatedPrivileges(delegate()
                    //{
                    ddlLists.Items.Clear();
                    List<ListItem> imageListItems = new List<ListItem>();
                    SPListCollection docLibraryColl = SPContext.Current.Web.GetListsOfType(SPBaseType.GenericList);

                    foreach (SPList list in docLibraryColl)
                    {
                        if (!list.Hidden)
                        {
                            //if (list.GetType() == typeof(SPPictureLibrary) ||
                            //    list.TemplateFeatureId.ToString() == "4bcccd62-dcaf-46dc-a7d4-e38277ef33f4" ||
                            //    list.TemplateFeatureId.ToString() == "bb8630c8-73c5-4a62-abf8-6d7d8bcb0e81")
                            {
                                imageListItems.Add(new ListItem() { Text = list.Title, Value = list.ID.ToString() });
                            }
                        }
                    }
                    imageListItems.Sort(delegate(ListItem l1, ListItem l2)
                    {
                        return l1.Text.CompareTo(l2.Text);
                    });
                    imageListItems.Insert(0, new ListItem() { Text = "--Select List--" });
                    foreach (ListItem li in imageListItems)
                    {
                        ddlLists.Items.Add(li);
                    }
                    ParentWebPart = WebPartToEdit as RightNav;
                    SetListSelectedText(ParentWebPart.ListName, "--Select List--", ddlLists);
                    //});
                }
                catch (Exception ex)
                {
                    // Log(ex);
                }
            }
            #endregion
        }

4. In your .ascx.cs file place the following method

You may have to write some extra code to utilize the properties here in the .ascx.cs file

public override EditorPartCollection CreateEditorParts()
        {
            EditorPartCollection epc = null;
            try
            {
                List<EditorPart> lstEditorPart = new List<EditorPart>();
                RightNavEditorPart ep = new RightNavEditorPart();
                ep.ID = this.ID + "_EditorPart";
                lstEditorPart.Add(ep);
                epc = base.CreateEditorParts();
                epc = new EditorPartCollection(epc, lstEditorPart);
            }
            catch (Exception ex)
            {

            }
            return epc;
        }

Let me know if you have any questions

Answer 2

You're basically asking how one can dynamically add values to an enum. The short answer is it is difficult/not worth the hassle. Others, it seems, have had success with a workaround where you create a custom tool pane and override the rendering method to draw your own drop down.

See here.

Incidentally, a similar question has been asked previously, here.