scriptcontrolbase.cs

AJAX 应用 实现页面的无刷新

// (c) Copyright Microsoft Corporation.
// This source is subject to the Microsoft Permissive License.
// See http://www.microsoft.com/resources/sharedsource/licensingbasics/sharedsourcelicenses.mspx.
// All other rights reserved.

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Web.Script.Serialization;
using System.Collections.Generic;
using System.ComponentModel;
using System.Globalization;
using System.Collections.Specialized;
using System.Diagnostics;
using System.Reflection;
using System.Security;

namespace AjaxControlToolkit
{
    /// <summary>
    /// ScriptControl is used to define complex custom controls which support ASP.NET AJAX script extensions
    /// </summary>
    [ClientScriptResource(null, Constants.BaseScriptResourceName)]
    public class ScriptControlBase : ScriptControl, INamingContainer, IControlResolver, IPostBackDataHandler, ICallbackEventHandler, IClientStateManager
    {
        #region [ Fields ]

        private ScriptManager _scriptManager;
        private bool _enableClientState;
        private string _cachedClientStateFieldID;
        private string _callbackArgument;
        private string _tagName;
        private HtmlTextWriterTag _tagKey;
        private bool _renderingScript;

        #endregion

        #region [ Constructor ]

        /// <summary>
        /// Initializes a new ScriptControl
        /// </summary>
        /// <param name="tag"></param>
        public ScriptControlBase(HtmlTextWriterTag tag)
            : this(false, tag)
        {
        }

        /// <summary>
        /// Initializes a new ScriptControl
        /// </summary>
        protected ScriptControlBase()
            : this(false)
        {
        }

        /// <summary>
        /// Initializes a new ScriptControl
        /// </summary>
        /// <param name="tag"></param>
        protected ScriptControlBase(string tag)
            : this(false, tag)
        {
        }

        /// <summary>
        /// Initializes a new ScriptControl
        /// </summary>
        /// <param name="enableClientState"></param>
        protected ScriptControlBase(bool enableClientState)
        {
            _enableClientState = enableClientState;
        }

        /// <summary>
        /// Initializes a new ScriptControl
        /// </summary>
        /// <param name="enableClientState"></param>
        /// <param name="tag"></param>
        protected ScriptControlBase(bool enableClientState, HtmlTextWriterTag tag)
        {
            _tagKey = tag;
            _enableClientState = enableClientState;
        }

        /// <summary>
        /// Initializes a new ScriptControl
        /// </summary>
        /// <param name="enableClientState"></param>
        /// <param name="tag"></param>
        protected ScriptControlBase(bool enableClientState, string tag)
        {
            _tagKey = HtmlTextWriterTag.Unknown;
            _tagName = tag;
            _enableClientState = enableClientState;
        }

        #endregion

        #region [ Properties ]

        /// <summary>
        /// For debugging - setting this causes the extender to load the specified script instead of the one out of the resources.  This
        /// lets you set breakpoints and modify the script without rebuilding, etc.
        /// </summary>
        /// <remarks>
        /// Note to inheritors: If you do not wish the user to set the script path, override script path and throw a NotSupportedException on set.  Also decorate the ScriptPath attribute with a [Browsable(false)] and [EditorBrowsableState(EditorBrowsableState.Never)]
        /// </remarks>
        [DefaultValue("")]
        public virtual string ScriptPath
        {
            get { return (string)(ViewState["ScriptPath"] ?? string.Empty); }
            set { ViewState["ScriptPath"] = value; }
        }

        /// <summary>
        /// The script type to use for the ScriptControl
        /// </summary>
        protected virtual string ClientControlType
        {
            get
            {
                ClientScriptResourceAttribute attr = (ClientScriptResourceAttribute)TypeDescriptor.GetAttributes(this)[typeof(ClientScriptResourceAttribute)];
                return attr.ComponentType;
            }
        }

        /// <summary>
        /// Property for determining if script rendering is currently underway.  This is used to determine
        /// if Script or markup is being rendered.
        /// </summary>
        protected bool IsRenderingScript
        {
            get
            {
                return _renderingScript;
            }
        }

        /// <summary>
        /// Whether this control supports ClientState
        /// </summary>
        /// <remarks>
        /// Note to inheritors: You should either pass true to the constructor for enableClientState or override this property to enable client state for inherited controls.
        /// </remarks>
        protected virtual bool SupportsClientState
        {
            get { return _enableClientState; }
        }

        /// <summary>
        /// Gets the ScriptManager for the page
        /// </summary>
        protected ScriptManager ScriptManager
        {
            get
            {
                EnsureScriptManager();
                return _scriptManager;
            }
        }

        /// <summary>
        /// The ID of the ClientState field
        /// </summary>
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1706:ShortAcronymsShouldBeUppercase", Justification = "Following ASP.NET AJAX pattern")]
        protected string ClientStateFieldID
        {
            get
            {
                if (_cachedClientStateFieldID == null)
                {
                    _cachedClientStateFieldID = ClientID + "_ClientState";
                }
                return _cachedClientStateFieldID;
            }
        }

        /// <summary>
        /// Gets the tag key used when rendering the outer wrapper element for this user control
        /// </summary>
        protected override HtmlTextWriterTag TagKey
        {
            get { return _tagKey; }
        }

        /// <summary>
        /// Gets the tag name used when rendering the outer wrapper element for this user control
        /// </summary>
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Globalization", "CA1308:NormalizeStringsToUppercase", Justification="Avoiding possibly breaking change")]
        protected override string TagName
        {
            get
            {
                if (_tagName == null && TagKey != HtmlTextWriterTag.Unknown)
                {
                    _tagName = Enum.Format(typeof(HtmlTextWriterTag), TagKey, "G").ToLower(CultureInfo.InvariantCulture);
                }
                return _tagName;
            }
        }

        #endregion

        #region [ Methods ]

        /// <summary>
        /// Ensures a ScriptManager exists on the Page for this Control
        /// </summary>
        private void EnsureScriptManager()
        {
            if (_scriptManager == null)
            {
                _scriptManager = ScriptManager.GetCurrent(Page);
                if (_scriptManager == null)
                {
                    throw new HttpException(Resources.E_NoScriptManager);
                }
            }
        }

        /// <summary>
        /// Finds a control reference by its ID
        /// </summary>
        /// <param name="id"></param>
        /// <returns></returns>
        public override Control FindControl(string id)
        {
            Control control = base.FindControl(id);