ControlDesigner.TemplateGroups Property

Definition

Namespace:

System.Web.UI.Design

Assembly:

System.Design.dll

Gets a collection of template groups, each containing one or more template definitions.

C#

public virtual System.Web.UI.Design.TemplateGroupCollection TemplateGroups { get; }

Property Value

TemplateGroupCollection

A collection of TemplateGroup objects. The default is an empty TemplateGroupCollection.

Examples

The following code example demonstrates how to create a control designer class that derives from the ControlDesigner class. This control designer supports a control with four possible templates.

To try it, compile the code, and then, in a design host such as Visual Studio 2005, view the page in Design view. Select the control, click the action list to select a template to modify, and then use the drag-and-drop feature to move controls into the template.

C#

using System;
using System.ComponentModel;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.Design;

namespace ASPNet.Design.Samples
{
    // Set an attribute reference to the designer, and define 
    // the HTML markup that the toolbox will write into the source.
    [Designer(typeof(TemplateGroupsSampleDesigner)),
        ToolboxData("<{0}:TemplateGroupsSample runat=server></{0}:TemplateGroupsSample>")]
    public sealed class TemplateGroupsSample : WebControl, INamingContainer
    {
        // Field for the templates
        private ITemplate[] _templates;

        // Constructor
        public TemplateGroupsSample()
        {
            _templates = new ITemplate[4];
        }

        // For each template property, set the designer attributes 
        // so the property does not appear in the property grid, but 
        // changes to the template are persisted in the control.
        [Browsable(false),
            PersistenceMode(PersistenceMode.InnerProperty)]
        public ITemplate Template1
        {
            get { return _templates[0]; }
            set { _templates[0] = value; }
        }
        [Browsable(false),
            PersistenceMode(PersistenceMode.InnerProperty)]
        public ITemplate Template2
        {
            get { return _templates[1]; }
            set { _templates[1] = value; }
        }
        [Browsable(false),
            PersistenceMode(PersistenceMode.InnerProperty)]
        public ITemplate Template3
        {
            get { return _templates[2]; }
            set { _templates[2] = value; }
        }
        [Browsable(false),
            PersistenceMode(PersistenceMode.InnerProperty)]
        public ITemplate Template4
        {
            get { return _templates[3]; }
            set { _templates[3] = value; }
        }

        protected override void CreateChildControls()
        {
            // Instantiate each template inside a panel
            // then add the panel to the Controls collection
            for (int i = 0; i < 4; i++)
            {
                Panel pan = new Panel();
                _templates[i].InstantiateIn(pan);
                this.Controls.Add(pan);
            }
        }
    }

    // Designer for the TemplateGroupsSample control
    public class TemplateGroupsSampleDesigner : ControlDesigner
    {
        TemplateGroupCollection col = null;

        public override void Initialize(IComponent component)
        {
            // Initialize the base
            base.Initialize(component);
            // Turn on template editing
            SetViewFlags(ViewFlags.TemplateEditing, true);
        }

        // Add instructions to the placeholder view of the control
        public override string GetDesignTimeHtml()
        {
            return CreatePlaceHolderDesignTimeHtml("Click here and use " +
                "the task menu to edit the templates.");
        }

        public override TemplateGroupCollection TemplateGroups
        {
            get
            {

                if (col == null)
                {
                    // Get the base collection
                    col = base.TemplateGroups;

                    // Create variables
                    TemplateGroup tempGroup;
                    TemplateDefinition tempDef;
                    TemplateGroupsSample ctl;

                    // Get reference to the component as TemplateGroupsSample
                    ctl = (TemplateGroupsSample)Component;

                    // Create a TemplateGroup
                    tempGroup = new TemplateGroup("Template Set A");

                    // Create a TemplateDefinition
                    tempDef = new TemplateDefinition(this, "Template A1", 
                        ctl, "Template1", true);

                    // Add the TemplateDefinition to the TemplateGroup
                    tempGroup.AddTemplateDefinition(tempDef);

                    // Create another TemplateDefinition
                    tempDef = new TemplateDefinition(this, "Template A2", 
                        ctl, "Template2", true);

                    // Add the TemplateDefinition to the TemplateGroup
                    tempGroup.AddTemplateDefinition(tempDef);

                    // Add the TemplateGroup to the TemplateGroupCollection
                    col.Add(tempGroup);

                    // Create another TemplateGroup and populate it
                    tempGroup = new TemplateGroup("Template Set B");
                    tempDef = new TemplateDefinition(this, "Template B1", 
                        ctl, "Template3", true);
                    tempGroup.AddTemplateDefinition(tempDef);
                    tempDef = new TemplateDefinition(this, "Template B2", 
                        ctl, "Template4", true);
                    tempGroup.AddTemplateDefinition(tempDef);

                    // Add the TemplateGroup to the TemplateGroupCollection
                    col.Add(tempGroup);
                }

                return col;
            }
        }

        // Do not allow direct resizing unless in TemplateMode
        public override bool AllowResize
        {
            get
            {
                if (this.InTemplateMode)
                    return true;
                else
                    return false;
            }
        }
    }
}

Notes to Inheritors

You can modify the TemplateGroups collection directly, or you can leave it unchanged. If you are overriding the TemplateGroups property, call the base implementation before you add template groups to the collection.

Applies to

See also

• TemplateGroup
• TemplateDefinition
• TemplatedControlDesigner
• ASP.NET Control Designers Overview