Label.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / xsp / System / Web / UI / WebControls / Label.cs / 1305376 / Label.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

namespace System.Web.UI.WebControls { 
 
    using System;
    using System.ComponentModel; 
    using System.Web;
    using System.Web.UI;
    using System.Web.Util;
 

 
    ///  
    /// Interacts with the parser to build a  control.
    ///  
    public class LabelControlBuilder : ControlBuilder {


        ///  
        /// 
        ///    Specifies whether white space literals are allowed. 
        ///  
        public override bool AllowWhitespaceLiterals() {
            return false; 
        }
    }

 

    ///  
    ///    Constructs a label for displaying text programmatcially on a 
    ///       page.
    ///  
    [
    ControlBuilderAttribute(typeof(LabelControlBuilder)),
    ControlValueProperty("Text"),
    DataBindingHandler("System.Web.UI.Design.TextDataBindingHandler, " + AssemblyRef.SystemDesign), 
    DefaultProperty("Text"),
    ParseChildren(false), 
    Designer("System.Web.UI.Design.WebControls.LabelDesigner, " + AssemblyRef.SystemDesign), 
    ToolboxData("<{0}:Label runat=\"server\" Text=\"Label\">")
    ] 
    public class Label : WebControl, ITextControl {

        private bool _textSetByAddParsedSubObject = false;
 
        /// 
        /// Initializes a new instance of the  class and renders 
        ///    it as a SPAN tag. 
        /// 
        public Label() { 
        }


        ///  
        /// 
        internal Label(HtmlTextWriterTag tag) : base(tag) { 
        } 

 
        /// 
        /// [To be supplied.]
        /// 
        [ 
        DefaultValue(""),
        IDReferenceProperty(), 
        TypeConverter(typeof(AssociatedControlConverter)), 
        WebCategory("Accessibility"),
        WebSysDescription(SR.Label_AssociatedControlID), 
        Themeable(false)
        ]
        public virtual string AssociatedControlID {
            get { 
                string s = (string)ViewState["AssociatedControlID"];
                return (s == null) ? String.Empty : s; 
            } 
            set {
                ViewState["AssociatedControlID"] = value; 
            }
        }

        internal bool AssociatedControlInControlTree { 
            get {
                object o = ViewState["AssociatedControlNotInControlTree"]; 
                return (o == null ? true : (bool)o); 
            }
            set { 
                ViewState["AssociatedControlNotInControlTree"] = value;
            }
        }
 
        public override bool SupportsDisabledAttribute {
            get { 
                return RenderingCompatibility < VersionUtil.Framework40; 
            }
        } 

        internal override bool RequiresLegacyRendering {
            get {
                return true; 
            }
        } 
 

        protected override HtmlTextWriterTag TagKey { 
            get {
                if (AssociatedControlID.Length != 0) {
                    return HtmlTextWriterTag.Label;
                } 
                return base.TagKey;
            } 
        } 

 
        /// 
        /// Gets or sets the text content of the 
        /// control.
        ///  
        [
        Localizable(true), 
        Bindable(true), 
        WebCategory("Appearance"),
        DefaultValue(""), 
        WebSysDescription(SR.Label_Text),
        PersistenceMode(PersistenceMode.InnerDefaultProperty)
        ]
        public virtual string Text { 
            get {
                object o = ViewState["Text"]; 
                return((o == null) ? String.Empty : (string)o); 
            }
            set { 
                if (HasControls()) {
                    Controls.Clear();
                }
                ViewState["Text"] = value; 
            }
        } 
 

        protected override void AddAttributesToRender(HtmlTextWriter writer) { 
            string associatedControlID = AssociatedControlID;
            if (associatedControlID.Length != 0) {
                if (AssociatedControlInControlTree) {
                    Control wc = FindControl(associatedControlID); 
                    if (wc == null) {
                        // Don't throw in the designer. 
                        if (!DesignMode) 
                            throw new HttpException(SR.GetString(SR.LabelForNotFound, associatedControlID, ID));
                    } 
                    else {
                        writer.AddAttribute(HtmlTextWriterAttribute.For, wc.ClientID);
                    }
                } 
                else {
                    writer.AddAttribute(HtmlTextWriterAttribute.For, associatedControlID); 
                } 
            }
 
            base.AddAttributesToRender(writer);
        }

 
        /// 
        ///  
        ///  
        protected override void AddParsedSubObject(object obj) {
            if (HasControls()) { 
                base.AddParsedSubObject(obj);
            }
            else {
                if (obj is LiteralControl) { 
                    if (_textSetByAddParsedSubObject) {
                        Text += ((LiteralControl)obj).Text; 
                    } 
                    else {
                        Text = ((LiteralControl)obj).Text; 
                    }
                    _textSetByAddParsedSubObject = true;
                }
                else { 
                    string currentText = Text;
                    if (currentText.Length != 0) { 
                        Text = String.Empty; 
                        base.AddParsedSubObject(new LiteralControl(currentText));
                    } 
                    base.AddParsedSubObject(obj);
                }
            }
        } 

 
        ///  
        /// 
        ///    Load previously saved state. 
        ///       Overridden to synchronize Text property with LiteralContent.
        /// 
        protected override void LoadViewState(object savedState) {
            if (savedState != null) { 
                base.LoadViewState(savedState);
                string s = (string)ViewState["Text"]; 
                // Dev10 703061 If Text is set, we want to clear out any child controls, but not dirty viewstate 
                if (s != null && HasControls()) {
                    Controls.Clear(); 
                }
            }
        }
 

        ///  
        ///  
        /// Renders the contents of the  into the specified writer.
        ///  
        protected internal override void RenderContents(HtmlTextWriter writer) {
            if (HasRenderingData()) {
                base.RenderContents(writer);
            } 
            else {
                writer.Write(Text); 
            } 
        }
    } 
}


// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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Label.cs source code in C# .NET

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