GlobalDataBindingHandler.cs source code in C# .NET

Source code for the .NET framework in C#

                        

Code:

/ FX-1434 / FX-1434 / 1.0 / untmp / whidbey / REDBITS / ndp / fx / src / Designer / WebForms / System / Web / UI / Design / GlobalDataBindingHandler.cs / 1 / GlobalDataBindingHandler.cs

                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

namespace System.Web.UI.Design { 
 
    using System;
    using System.Collections; 
    using System.ComponentModel;
    using System.ComponentModel.Design;
    using Microsoft.Win32;
    using System.Diagnostics; 
    using System.Reflection;
    using System.Web.UI; 
 
    //using DataBinding = System.Web.UI.DataBinding;
 
    /// 
    /// 
    /// 
    [System.Security.Permissions.SecurityPermission(System.Security.Permissions.SecurityAction.Demand, Flags=System.Security.Permissions.SecurityPermissionFlag.UnmanagedCode)] 
    internal sealed class GlobalDataBindingHandler {
 
        public static readonly EventHandler Handler = new EventHandler(GlobalDataBindingHandler.OnDataBind); 
        private static Hashtable dataBindingHandlerTable;
 
        /// 
        /// 
        /// 
        private GlobalDataBindingHandler() { 
        }
 
        ///  
        /// 
        ///  
        private static Hashtable DataBindingHandlerTable {
            get {
                if (dataBindingHandlerTable == null) {
                    dataBindingHandlerTable = new Hashtable(); 
                }
                return dataBindingHandlerTable; 
            } 
        }
 
        /// 
        /// 
        /// 
        public static void OnDataBind(object sender, EventArgs e) { 
            Debug.Assert(sender is Control, "DataBindings can only be present on Controls.");
            Control control = (Control)sender; 
 
            // check if this control has any data-bindings
            IDataBindingsAccessor dataBindingsAccessor = (IDataBindingsAccessor)sender; 
            if (dataBindingsAccessor.HasDataBindings == false) {
                return;
            }
 
            // check if the control type has an associated data-binding handler
            DataBindingHandlerAttribute handlerAttribute = 
                (DataBindingHandlerAttribute)TypeDescriptor.GetAttributes(sender)[typeof(DataBindingHandlerAttribute)]; 
            if ((handlerAttribute == null) || (handlerAttribute.HandlerTypeName.Length == 0)) {
                return; 
            }

            // components in the designer/container do not get handled here; the
            // designer for that control handles it in its own special way 
            ISite site = control.Site;
            IDesignerHost designerHost = null; 
            if (site == null) { 
                Page page = control.Page;
                if (page != null) { 
                    site = page.Site;
                }
                else {
                    // When the designer is working on a UserControl instead of a Page 

                    Control parent = control.Parent; 
 
                    // We shouldn't have to walk up the parent chain a whole lot - maybe a couple
                    // of levels on the average 
                    while ((site == null) && (parent != null)) {
                        if (parent.Site != null) {
                            site = parent.Site;
                        } 
                        parent = parent.Parent;
                    } 
                } 
            }
            if (site != null) { 
                designerHost = (IDesignerHost)site.GetService(typeof(IDesignerHost));
            }
            if (designerHost == null) {
                Debug.Fail("Did not get back an IDesignerHost"); 
                return;
            } 
 
            // non-top level components, such as controls within templates do not have designers
            // these are the only things that need the data-binding handler stuff 
            IDesigner designer = designerHost.GetDesigner(control);
            if (designer != null) {
                return;
            } 

            // get the handler and cache it the first time around 
            DataBindingHandler dataBindingHandler = null; 
            try {
                string handlerTypeName = handlerAttribute.HandlerTypeName; 
                dataBindingHandler = (DataBindingHandler)DataBindingHandlerTable[handlerTypeName];

                if (dataBindingHandler == null) {
                    Type handlerType = Type.GetType(handlerTypeName); 
                    if (handlerType != null) {
                        dataBindingHandler = (DataBindingHandler)Activator.CreateInstance(handlerType, BindingFlags.Instance | BindingFlags.Public | BindingFlags.CreateInstance, null, null, null); 
                        DataBindingHandlerTable[handlerTypeName] = dataBindingHandler; 
                    }
                } 
            }
            catch (Exception ex) {
                Debug.Fail(ex.ToString());
                return; 
            }
 
            // finally delegate to it to handle this particular control 
            if (dataBindingHandler != null) {
                dataBindingHandler.DataBindControl(designerHost, control); 
            }
        }
    }
} 


// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
                        

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