Button.cs source code in C# .NET

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Code:

/ 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / xsp / System / Web / UI / WebControls / Button.cs / 1305376 / Button.cs

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

namespace System.Web.UI.WebControls { 
 
    using System;
    using System.Collections; 
    using System.Collections.Specialized;
    using System.ComponentModel;
    using System.Drawing.Design;
    using System.Web; 
    using System.Web.UI;
    using System.Web.Util; 
 

    ///  
    ///    Represents a Windows button control.
    /// 
    [
    DataBindingHandler("System.Web.UI.Design.TextDataBindingHandler, " + AssemblyRef.SystemDesign), 
    DefaultEvent("Click"),
    DefaultProperty("Text"), 
    Designer("System.Web.UI.Design.WebControls.ButtonDesigner, " + AssemblyRef.SystemDesign), 
    ToolboxData("<{0}:Button runat=\"server\" Text=\"Button\">"),
    SupportsEventValidation 
    ]
    public class Button : WebControl, IButtonControl, IPostBackEventHandler {

        private static readonly object EventClick = new object(); 
        private static readonly object EventCommand = new object();
 
 
        /// 
        /// Initializes a new instance of the  class. 
        /// 
        public Button() : base(HtmlTextWriterTag.Input) {
        }
 

        ///  
        ///    Gets or sets whether pressing the button causes page validation to fire. This defaults to True so that when 
        ///          using validation controls, the validation state of all controls are updated when the button is clicked, both
        ///          on the client and the server. Setting this to False is useful when defining a cancel or reset button on a page 
        ///          that has validators.
        /// 
        [
        DefaultValue(true), 
        Themeable(false),
        WebCategory("Behavior"), 
        WebSysDescription(SR.Button_CausesValidation), 
        ]
        public virtual bool CausesValidation { 
            get {
                object b = ViewState["CausesValidation"];
                return((b == null) ? true : (bool)b);
            } 
            set {
                ViewState["CausesValidation"] = value; 
            } 
        }
 

        /// 
        /// Gets or sets the command associated with a  propogated in the  event along with the 
        /// property. 
        /// 
        [ 
        DefaultValue(""), 
        Themeable(false),
        WebCategory("Behavior"), 
        WebSysDescription(SR.WebControl_CommandName),
        ]
        public string CommandName {
            get { 
                string s = (string)ViewState["CommandName"];
                return((s == null) ? String.Empty : s); 
            } 
            set {
                ViewState["CommandName"] = value; 
            }
        }

 
        /// 
        ///    Gets or sets the property propogated in 
        ///       the  event with the associated  
        ///       property.
        ///  
        [
        Bindable(true),
        DefaultValue(""),
        Themeable(false), 
        WebCategory("Behavior"),
        WebSysDescription(SR.WebControl_CommandArgument), 
        ] 
        public string CommandArgument {
            get { 
                string s = (string)ViewState["CommandArgument"];
                return((s == null) ? String.Empty : s);
            }
            set { 
                ViewState["CommandArgument"] = value;
            } 
        } 

 
        /// 
        ///    The script that is executed on a client-side click.
        /// 
        [ 
        DefaultValue(""),
        Themeable(false), 
        WebCategory("Behavior"), 
        WebSysDescription(SR.Button_OnClientClick),
        ] 
        public virtual string OnClientClick {
            get {
                string s = (string)ViewState["OnClientClick"];
                if (s == null) { 
                    return String.Empty;
                } 
                return s; 
            }
            set { 
                ViewState["OnClientClick"] = value;
            }
        }
 

        [ 
        DefaultValue(""), 
        Editor("System.Web.UI.Design.UrlEditor, " + AssemblyRef.SystemDesign, typeof(UITypeEditor)),
        Themeable(false), 
        UrlProperty("*.aspx"),
        WebCategory("Behavior"),
        WebSysDescription(SR.Button_PostBackUrl),
        ] 
        public virtual string PostBackUrl {
            get { 
                string s = (string)ViewState["PostBackUrl"]; 
                return s == null? String.Empty : s;
            } 
            set {
                ViewState["PostBackUrl"] = value;
            }
        } 

 
        ///  
        /// Gets or sets the text caption displayed on the  .
        ///  
        [
        Bindable(true),
        Localizable(true),
        WebCategory("Appearance"), 
        DefaultValue(""),
        WebSysDescription(SR.Button_Text), 
        ] 
        public string Text {
            get { 
                string s = (string)ViewState["Text"];
                return((s == null) ? String.Empty : s);
            }
            set { 
                ViewState["Text"] = value;
            } 
        } 

 
        /// 
        /// Whether the button should use the client's submit mechanism to implement its
        /// behavior, or whether it should use the ASP.NET postback mechanism similar
        /// to LinkButton. By default, it uses the browser's submit mechanism. 
        /// 
        [ 
        DefaultValue(true), 
        Themeable(false),
        WebCategory("Behavior"), 
        WebSysDescription(SR.Button_UseSubmitBehavior),
        ]
        public virtual bool UseSubmitBehavior {
            get { 
                object b = ViewState["UseSubmitBehavior"];
                return ((b == null) ? true : (bool)b); 
            } 
            set {
                ViewState["UseSubmitBehavior"] = value; 
            }
        }

 
        [
        DefaultValue(""), 
        Themeable(false), 
        WebCategory("Behavior"),
        WebSysDescription(SR.PostBackControl_ValidationGroup), 
        ]
        public virtual string ValidationGroup {
            get {
                string s = (string)ViewState["ValidationGroup"]; 
                return((s == null) ? String.Empty : s);
            } 
            set { 
                ViewState["ValidationGroup"] = value;
            } 
        }


        ///  
        /// Occurs when the  is clicked.
        ///  
        [ 
        WebCategory("Action"),
        WebSysDescription(SR.Button_OnClick) 
        ]
        public event EventHandler Click {
            add {
                Events.AddHandler(EventClick, value); 
            }
            remove { 
                Events.RemoveHandler(EventClick, value); 
            }
        } 



        ///  
        /// Occurs when the  is clicked.
        ///  
        [ 
        WebCategory("Action"),
        WebSysDescription(SR.Button_OnCommand) 
        ]
        public event CommandEventHandler Command {
            add {
                Events.AddHandler(EventCommand, value); 
            }
            remove { 
                Events.RemoveHandler(EventCommand, value); 
            }
        } 


        /// 
        ///  
        /// Adds the attributes of the  control to the output stream for rendering
        ///    on the client. 
        ///  
        protected override void AddAttributesToRender(HtmlTextWriter writer) {
            bool submitButton = UseSubmitBehavior; 

            // Make sure we are in a form tag with runat=server.
            if (Page != null) {
                Page.VerifyRenderingInServerForm(this); 
            }
 
            if (submitButton) { 
                writer.AddAttribute(HtmlTextWriterAttribute.Type, "submit");
            } 
            else {
                writer.AddAttribute(HtmlTextWriterAttribute.Type, "button");
            }
 
            PostBackOptions options = GetPostBackOptions();
            string uniqueID = UniqueID; 
 
            // Don't render Name on a button if __doPostBack is posting back to a different control
            // because Page will register this control as requiring post back notification even though 
            // it's not the target of the postback.  If the TargetControl isn't this control, this control's
            // RaisePostBackEvent should never get called.  See VSWhidbey 477095.
            if (uniqueID != null && (options == null || options.TargetControl == this)) {
                writer.AddAttribute(HtmlTextWriterAttribute.Name, uniqueID); 
            }
 
 
            writer.AddAttribute(HtmlTextWriterAttribute.Value, Text);
 
            //

            bool effectiveEnabled = IsEnabled;
 
            string onClick = String.Empty;
 
            if (effectiveEnabled) { 
                // Need to merge the onclick attribute with the OnClientClick
 
                // VSWhidbey 111791: Defensively add a ';' in case it is
                // missing in user customized onClick value above.
                onClick = Util.EnsureEndWithSemiColon(OnClientClick);
 
                if (HasAttributes) {
                    string userOnClick = Attributes["onclick"]; 
                    if (userOnClick != null) { 
                        onClick += Util.EnsureEndWithSemiColon(userOnClick);
                        Attributes.Remove("onclick"); 
                    }
                }

                if (Page != null) { 
                    string reference = Page.ClientScript.GetPostBackEventReference(options, false);
                    if (reference != null) { 
                        onClick = Util.MergeScript(onClick, reference); 
                    }
                } 
            }

            if (Page != null) {
                Page.ClientScript.RegisterForEventValidation(options); 
            }
 
            if (onClick.Length > 0) { 
                writer.AddAttribute(HtmlTextWriterAttribute.Onclick, onClick);
 
                if (EnableLegacyRendering) {
                    writer.AddAttribute("language", "javascript", false);
                }
            } 

            if (Enabled && !effectiveEnabled && SupportsDisabledAttribute) { 
                // We need to do the cascade effect on the server, because the browser 
                // only renders as disabled, but doesn't disable the functionality.
                writer.AddAttribute(HtmlTextWriterAttribute.Disabled, "disabled"); 
            }

            base.AddAttributesToRender(writer);
        } 

        protected virtual PostBackOptions GetPostBackOptions() { 
            PostBackOptions options = new PostBackOptions(this, String.Empty); 
            options.ClientSubmit = false;
 
            if (Page != null) {
                if (CausesValidation && Page.GetValidators(ValidationGroup).Count > 0) {
                    options.PerformValidation = true;
                    options.ValidationGroup = ValidationGroup; 
                }
 
                if (!String.IsNullOrEmpty(PostBackUrl)) { 
                    options.ActionUrl = HttpUtility.UrlPathEncode(ResolveClientUrl(PostBackUrl));
                } 
                options.ClientSubmit = !UseSubmitBehavior;
            }

            return options; 
        }
 
 
        /// 
        /// Raises the event of a  
        /// .
        /// 
        protected virtual void OnClick(EventArgs e) {
            EventHandler handler = (EventHandler)Events[EventClick]; 
            if (handler != null) handler(this,e);
        } 
 

        ///  
        /// Raises the event of a 
        /// .
        /// 
        protected virtual void OnCommand(CommandEventArgs e) { 
            CommandEventHandler handler = (CommandEventHandler)Events[EventCommand];
            if (handler != null) 
                handler(this,e); 

            // Command events are bubbled up the control heirarchy 
            RaiseBubbleEvent(this, e);
        }

        protected internal override void OnPreRender(EventArgs e) { 
            base.OnPreRender(e);
 
            // VSWhidbey 489577 
            if (Page != null && IsEnabled) {
                if ((CausesValidation && Page.GetValidators(ValidationGroup).Count > 0) || 
                     !String.IsNullOrEmpty(PostBackUrl)) {
                    Page.RegisterWebFormsScript();
                }
                else if (!UseSubmitBehavior) { 
                    Page.RegisterPostBackScript();
                } 
            } 
        }
 
        /// 
        /// 
        /// 
        protected internal override void RenderContents(HtmlTextWriter writer) { 
            // Do not render the children of a button since it does not
            // make sense to have children of an  tag. 
        } 

 
        /// 
        /// 
        /// Raises events for the 
        /// control on post back. 
        /// 
        void IPostBackEventHandler.RaisePostBackEvent(string eventArgument) { 
            RaisePostBackEvent(eventArgument); 
        }
 

        /// 
        /// 
        /// Raises events for the  
        /// control on post back.
        ///  
        protected virtual void RaisePostBackEvent(string eventArgument) { 
            ValidateEvent(this.UniqueID, eventArgument);
            if (CausesValidation) { 
                Page.Validate(ValidationGroup);
            }
            OnClick(EventArgs.Empty);
            OnCommand(new CommandEventArgs(CommandName, CommandArgument)); 
        }
    } 
} 


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

namespace System.Web.UI.WebControls { 
 
    using System;
    using System.Collections; 
    using System.Collections.Specialized;
    using System.ComponentModel;
    using System.Drawing.Design;
    using System.Web; 
    using System.Web.UI;
    using System.Web.Util; 
 

    ///  
    ///    Represents a Windows button control.
    /// 
    [
    DataBindingHandler("System.Web.UI.Design.TextDataBindingHandler, " + AssemblyRef.SystemDesign), 
    DefaultEvent("Click"),
    DefaultProperty("Text"), 
    Designer("System.Web.UI.Design.WebControls.ButtonDesigner, " + AssemblyRef.SystemDesign), 
    ToolboxData("<{0}:Button runat=\"server\" Text=\"Button\">"),
    SupportsEventValidation 
    ]
    public class Button : WebControl, IButtonControl, IPostBackEventHandler {

        private static readonly object EventClick = new object(); 
        private static readonly object EventCommand = new object();
 
 
        /// 
        /// Initializes a new instance of the  class. 
        /// 
        public Button() : base(HtmlTextWriterTag.Input) {
        }
 

        ///  
        ///    Gets or sets whether pressing the button causes page validation to fire. This defaults to True so that when 
        ///          using validation controls, the validation state of all controls are updated when the button is clicked, both
        ///          on the client and the server. Setting this to False is useful when defining a cancel or reset button on a page 
        ///          that has validators.
        /// 
        [
        DefaultValue(true), 
        Themeable(false),
        WebCategory("Behavior"), 
        WebSysDescription(SR.Button_CausesValidation), 
        ]
        public virtual bool CausesValidation { 
            get {
                object b = ViewState["CausesValidation"];
                return((b == null) ? true : (bool)b);
            } 
            set {
                ViewState["CausesValidation"] = value; 
            } 
        }
 

        /// 
        /// Gets or sets the command associated with a  propogated in the  event along with the 
        /// property. 
        /// 
        [ 
        DefaultValue(""), 
        Themeable(false),
        WebCategory("Behavior"), 
        WebSysDescription(SR.WebControl_CommandName),
        ]
        public string CommandName {
            get { 
                string s = (string)ViewState["CommandName"];
                return((s == null) ? String.Empty : s); 
            } 
            set {
                ViewState["CommandName"] = value; 
            }
        }

 
        /// 
        ///    Gets or sets the property propogated in 
        ///       the  event with the associated  
        ///       property.
        ///  
        [
        Bindable(true),
        DefaultValue(""),
        Themeable(false), 
        WebCategory("Behavior"),
        WebSysDescription(SR.WebControl_CommandArgument), 
        ] 
        public string CommandArgument {
            get { 
                string s = (string)ViewState["CommandArgument"];
                return((s == null) ? String.Empty : s);
            }
            set { 
                ViewState["CommandArgument"] = value;
            } 
        } 

 
        /// 
        ///    The script that is executed on a client-side click.
        /// 
        [ 
        DefaultValue(""),
        Themeable(false), 
        WebCategory("Behavior"), 
        WebSysDescription(SR.Button_OnClientClick),
        ] 
        public virtual string OnClientClick {
            get {
                string s = (string)ViewState["OnClientClick"];
                if (s == null) { 
                    return String.Empty;
                } 
                return s; 
            }
            set { 
                ViewState["OnClientClick"] = value;
            }
        }
 

        [ 
        DefaultValue(""), 
        Editor("System.Web.UI.Design.UrlEditor, " + AssemblyRef.SystemDesign, typeof(UITypeEditor)),
        Themeable(false), 
        UrlProperty("*.aspx"),
        WebCategory("Behavior"),
        WebSysDescription(SR.Button_PostBackUrl),
        ] 
        public virtual string PostBackUrl {
            get { 
                string s = (string)ViewState["PostBackUrl"]; 
                return s == null? String.Empty : s;
            } 
            set {
                ViewState["PostBackUrl"] = value;
            }
        } 

 
        ///  
        /// Gets or sets the text caption displayed on the  .
        ///  
        [
        Bindable(true),
        Localizable(true),
        WebCategory("Appearance"), 
        DefaultValue(""),
        WebSysDescription(SR.Button_Text), 
        ] 
        public string Text {
            get { 
                string s = (string)ViewState["Text"];
                return((s == null) ? String.Empty : s);
            }
            set { 
                ViewState["Text"] = value;
            } 
        } 

 
        /// 
        /// Whether the button should use the client's submit mechanism to implement its
        /// behavior, or whether it should use the ASP.NET postback mechanism similar
        /// to LinkButton. By default, it uses the browser's submit mechanism. 
        /// 
        [ 
        DefaultValue(true), 
        Themeable(false),
        WebCategory("Behavior"), 
        WebSysDescription(SR.Button_UseSubmitBehavior),
        ]
        public virtual bool UseSubmitBehavior {
            get { 
                object b = ViewState["UseSubmitBehavior"];
                return ((b == null) ? true : (bool)b); 
            } 
            set {
                ViewState["UseSubmitBehavior"] = value; 
            }
        }

 
        [
        DefaultValue(""), 
        Themeable(false), 
        WebCategory("Behavior"),
        WebSysDescription(SR.PostBackControl_ValidationGroup), 
        ]
        public virtual string ValidationGroup {
            get {
                string s = (string)ViewState["ValidationGroup"]; 
                return((s == null) ? String.Empty : s);
            } 
            set { 
                ViewState["ValidationGroup"] = value;
            } 
        }


        ///  
        /// Occurs when the  is clicked.
        ///  
        [ 
        WebCategory("Action"),
        WebSysDescription(SR.Button_OnClick) 
        ]
        public event EventHandler Click {
            add {
                Events.AddHandler(EventClick, value); 
            }
            remove { 
                Events.RemoveHandler(EventClick, value); 
            }
        } 



        ///  
        /// Occurs when the  is clicked.
        ///  
        [ 
        WebCategory("Action"),
        WebSysDescription(SR.Button_OnCommand) 
        ]
        public event CommandEventHandler Command {
            add {
                Events.AddHandler(EventCommand, value); 
            }
            remove { 
                Events.RemoveHandler(EventCommand, value); 
            }
        } 


        /// 
        ///  
        /// Adds the attributes of the  control to the output stream for rendering
        ///    on the client. 
        ///  
        protected override void AddAttributesToRender(HtmlTextWriter writer) {
            bool submitButton = UseSubmitBehavior; 

            // Make sure we are in a form tag with runat=server.
            if (Page != null) {
                Page.VerifyRenderingInServerForm(this); 
            }
 
            if (submitButton) { 
                writer.AddAttribute(HtmlTextWriterAttribute.Type, "submit");
            } 
            else {
                writer.AddAttribute(HtmlTextWriterAttribute.Type, "button");
            }
 
            PostBackOptions options = GetPostBackOptions();
            string uniqueID = UniqueID; 
 
            // Don't render Name on a button if __doPostBack is posting back to a different control
            // because Page will register this control as requiring post back notification even though 
            // it's not the target of the postback.  If the TargetControl isn't this control, this control's
            // RaisePostBackEvent should never get called.  See VSWhidbey 477095.
            if (uniqueID != null && (options == null || options.TargetControl == this)) {
                writer.AddAttribute(HtmlTextWriterAttribute.Name, uniqueID); 
            }
 
 
            writer.AddAttribute(HtmlTextWriterAttribute.Value, Text);
 
            //

            bool effectiveEnabled = IsEnabled;
 
            string onClick = String.Empty;
 
            if (effectiveEnabled) { 
                // Need to merge the onclick attribute with the OnClientClick
 
                // VSWhidbey 111791: Defensively add a ';' in case it is
                // missing in user customized onClick value above.
                onClick = Util.EnsureEndWithSemiColon(OnClientClick);
 
                if (HasAttributes) {
                    string userOnClick = Attributes["onclick"]; 
                    if (userOnClick != null) { 
                        onClick += Util.EnsureEndWithSemiColon(userOnClick);
                        Attributes.Remove("onclick"); 
                    }
                }

                if (Page != null) { 
                    string reference = Page.ClientScript.GetPostBackEventReference(options, false);
                    if (reference != null) { 
                        onClick = Util.MergeScript(onClick, reference); 
                    }
                } 
            }

            if (Page != null) {
                Page.ClientScript.RegisterForEventValidation(options); 
            }
 
            if (onClick.Length > 0) { 
                writer.AddAttribute(HtmlTextWriterAttribute.Onclick, onClick);
 
                if (EnableLegacyRendering) {
                    writer.AddAttribute("language", "javascript", false);
                }
            } 

            if (Enabled && !effectiveEnabled && SupportsDisabledAttribute) { 
                // We need to do the cascade effect on the server, because the browser 
                // only renders as disabled, but doesn't disable the functionality.
                writer.AddAttribute(HtmlTextWriterAttribute.Disabled, "disabled"); 
            }

            base.AddAttributesToRender(writer);
        } 

        protected virtual PostBackOptions GetPostBackOptions() { 
            PostBackOptions options = new PostBackOptions(this, String.Empty); 
            options.ClientSubmit = false;
 
            if (Page != null) {
                if (CausesValidation && Page.GetValidators(ValidationGroup).Count > 0) {
                    options.PerformValidation = true;
                    options.ValidationGroup = ValidationGroup; 
                }
 
                if (!String.IsNullOrEmpty(PostBackUrl)) { 
                    options.ActionUrl = HttpUtility.UrlPathEncode(ResolveClientUrl(PostBackUrl));
                } 
                options.ClientSubmit = !UseSubmitBehavior;
            }

            return options; 
        }
 
 
        /// 
        /// Raises the event of a  
        /// .
        /// 
        protected virtual void OnClick(EventArgs e) {
            EventHandler handler = (EventHandler)Events[EventClick]; 
            if (handler != null) handler(this,e);
        } 
 

        ///  
        /// Raises the event of a 
        /// .
        /// 
        protected virtual void OnCommand(CommandEventArgs e) { 
            CommandEventHandler handler = (CommandEventHandler)Events[EventCommand];
            if (handler != null) 
                handler(this,e); 

            // Command events are bubbled up the control heirarchy 
            RaiseBubbleEvent(this, e);
        }

        protected internal override void OnPreRender(EventArgs e) { 
            base.OnPreRender(e);
 
            // VSWhidbey 489577 
            if (Page != null && IsEnabled) {
                if ((CausesValidation && Page.GetValidators(ValidationGroup).Count > 0) || 
                     !String.IsNullOrEmpty(PostBackUrl)) {
                    Page.RegisterWebFormsScript();
                }
                else if (!UseSubmitBehavior) { 
                    Page.RegisterPostBackScript();
                } 
            } 
        }
 
        /// 
        /// 
        /// 
        protected internal override void RenderContents(HtmlTextWriter writer) { 
            // Do not render the children of a button since it does not
            // make sense to have children of an  tag. 
        } 

 
        /// 
        /// 
        /// Raises events for the 
        /// control on post back. 
        /// 
        void IPostBackEventHandler.RaisePostBackEvent(string eventArgument) { 
            RaisePostBackEvent(eventArgument); 
        }
 

        /// 
        /// 
        /// Raises events for the  
        /// control on post back.
        ///  
        protected virtual void RaisePostBackEvent(string eventArgument) { 
            ValidateEvent(this.UniqueID, eventArgument);
            if (CausesValidation) { 
                Page.Validate(ValidationGroup);
            }
            OnClick(EventArgs.Empty);
            OnCommand(new CommandEventArgs(CommandName, CommandArgument)); 
        }
    } 
} 


// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
                        

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