Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Web/UI/WebControls/DropDownList.cs

@@ -0,0 +1,203 @@
+//------------------------------------------------------------------------------
+// <copyright file="DropDownList.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//------------------------------------------------------------------------------
+
+namespace System.Web.UI.WebControls {
+
+    using System;
+    using System.Collections;
+    using System.ComponentModel;
+    using System.Collections.Specialized;
+    using System.Drawing;
+    using System.Web;
+    using System.Web.UI;
+    using System.Web.UI.WebControls.Adapters;
+
+    /// <devdoc>
+    ///    <para>Creates a control that allows the user to select a single item from a
+    ///       drop-down list.</para>
+    /// </devdoc>
+    [
+    SupportsEventValidation,
+    ValidationProperty("SelectedItem")
+    ]
+    public class DropDownList : ListControl, IPostBackDataHandler {
+
+
+        /// <devdoc>
+        /// <para>Initializes a new instance of the <see cref='System.Web.UI.WebControls.DropDownList'/> class.</para>
+        /// </devdoc>
+        public DropDownList() {
+        }
+
+
+        /// <devdoc>
+        ///    <para>[To be supplied.]</para>
+        /// </devdoc>
+        [
+        Browsable(false)
+        ]
+        public override Color BorderColor {
+            get {
+                return base.BorderColor;
+            }
+            set {
+                base.BorderColor = value;
+            }
+        }
+
+
+        /// <devdoc>
+        ///    <para>[To be supplied.]</para>
+        /// </devdoc>
+        [
+        Browsable(false)
+        ]
+        public override BorderStyle BorderStyle {
+            get {
+                return base.BorderStyle;
+            }
+            set {
+                base.BorderStyle = value;
+            }
+        }
+
+
+        /// <devdoc>
+        ///    <para>[To be supplied.]</para>
+        /// </devdoc>
+        [
+        Browsable(false)
+        ]
+        public override Unit BorderWidth {
+            get {
+                return base.BorderWidth;
+            }
+            set {
+                base.BorderWidth = value;
+            }
+        }
+
+        public override bool SupportsDisabledAttribute {
+            get {
+                return true;
+            }
+        }
+
+        /// <devdoc>
+        ///    <para>Gets or sets the index of the item selected by the user
+        ///       from the <see cref='System.Web.UI.WebControls.DropDownList'/>
+        ///       control.</para>
+        /// </devdoc>
+        [
+        WebCategory("Behavior"),
+        DefaultValue(0),
+        WebSysDescription(SR.WebControl_SelectedIndex),
+        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)
+        ]
+        public override int SelectedIndex {
+            get {
+                int selectedIndex = base.SelectedIndex;
+                if (selectedIndex < 0 && Items.Count > 0) {
+                    Items[0].Selected = true;
+                    selectedIndex = 0;
+                }
+                return selectedIndex;
+            }
+            set {
+                base.SelectedIndex = value;
+            }
+        }
+
+        internal override ArrayList SelectedIndicesInternal {
+            get {
+                int sideEffect = SelectedIndex;
+                return base.SelectedIndicesInternal;
+            }
+        }
+
+
+        protected override void AddAttributesToRender(HtmlTextWriter writer) {
+            string uniqueID = UniqueID;
+            if (uniqueID != null) {
+                writer.AddAttribute(HtmlTextWriterAttribute.Name, uniqueID);
+            }
+
+            base.AddAttributesToRender(writer);
+        }
+
+
+        protected override ControlCollection CreateControlCollection() {
+            return new EmptyControlCollection(this);
+        }
+
+        /// <internalonly/>
+        /// <devdoc>
+        /// <para>Process posted data for the <see cref='System.Web.UI.WebControls.DropDownList'/> control.</para>
+        /// </devdoc>
+        bool IPostBackDataHandler.LoadPostData(String postDataKey, NameValueCollection postCollection) {
+            return LoadPostData(postDataKey, postCollection);
+        }
+
+
+        /// <internalonly/>
+        /// <devdoc>
+        /// <para>Process posted data for the <see cref='System.Web.UI.WebControls.DropDownList'/> control.</para>
+        /// </devdoc>
+        protected virtual bool LoadPostData(String postDataKey, NameValueCollection postCollection) {
+
+            // When a DropDownList is disabled, then there is no postback data for it.
+            // Since DropDownList doesn't call RegisterRequiresPostBack, this method will
+            // never be called, so we don't need to worry about ignoring empty postback data.
+
+            string [] selectedItems = postCollection.GetValues(postDataKey);
+
+            EnsureDataBoundInLoadPostData();
+            if (selectedItems != null) {
+
+                ValidateEvent(postDataKey, selectedItems[0]);
+
+                int n = Items.FindByValueInternal(selectedItems[0], false);
+
+                if (SelectedIndex != n) {
+                    SetPostDataSelection(n);
+                    return true;
+                }
+            }
+
+            return false;
+        }
+
+
+        /// <internalonly/>
+        /// <devdoc>
+        /// <para>Raises events for the <see cref='System.Web.UI.WebControls.DropDownList'/> control on post back.</para>
+        /// </devdoc>
+        void IPostBackDataHandler.RaisePostDataChangedEvent() {
+            RaisePostDataChangedEvent();
+        }
+
+
+        /// <internalonly/>
+        /// <devdoc>
+        /// <para>Raises events for the <see cref='System.Web.UI.WebControls.DropDownList'/> control on post back.</para>
+        /// </devdoc>
+        protected virtual void RaisePostDataChangedEvent() {
+            if (AutoPostBack && !Page.IsPostBackEventControlRegistered) {
+                // VSWhidbey 204824
+                Page.AutoPostBackControl = this;
+
+                if (CausesValidation) {
+                    Page.Validate(ValidationGroup);
+                }
+            }
+            OnSelectedIndexChanged(EventArgs.Empty);
+        }
+
+        protected internal override void VerifyMultiSelect() {
+            throw new HttpException(SR.GetString(SR.Cant_Multiselect, "DropDownList"));
+        }
+    }
+}