BoundColumn.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 / xsp / System / Web / UI / WebControls / BoundColumn.cs / 1 / BoundColumn.cs
                        

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

namespace System.Web.UI.WebControls { 
 
    using System;
    using System.Collections; 
    using System.ComponentModel;
    using System.Globalization;
    using System.Web;
    using System.Web.UI; 
    using System.Security.Permissions;
    using System.Web.Util; 
 

    ///  
    /// Creates a column bounded to a data field in a .
    /// 
    [AspNetHostingPermission(SecurityAction.LinkDemand, Level=AspNetHostingPermissionLevel.Minimal)]
    [AspNetHostingPermission(SecurityAction.InheritanceDemand, Level=AspNetHostingPermissionLevel.Minimal)] 
    public class BoundColumn : DataGridColumn {
 
 
        /// 
        ///    Specifies a string that represents "this". This field is read-only.  
        /// 
        public static readonly string thisExpr = "!";

        private PropertyDescriptor boundFieldDesc; 
        private bool boundFieldDescValid;
        private string boundField; 
        private string formatting; 

 
        /// 
        /// Initializes a new instance of a  class.
        /// 
        public BoundColumn() { 
        }
 
 

        ///  
        ///     Gets or sets the field name from the data model bound to this column.
        /// 
        [
            WebCategory("Data"), 
            DefaultValue(""),
            WebSysDescription(SR.BoundColumn_DataField) 
        ] 
        public virtual string DataField {
            get { 
                object o = ViewState["DataField"];
                if (o != null)
                    return (string)o;
                return String.Empty; 
            }
            set { 
                ViewState["DataField"] = value; 
                OnColumnChanged();
            } 
        }


        ///  
        ///    Gets or sets the display format of data in this
        ///       column. 
        ///  
        [
            WebCategory("Behavior"), 
            DefaultValue(""),
            WebSysDescription(SR.BoundColumn_DataFormatString)
        ]
        public virtual string DataFormatString { 
            get {
                object o = ViewState["DataFormatString"]; 
                if (o != null) 
                    return (string)o;
                return String.Empty; 
            }
            set {
                ViewState["DataFormatString"] = value;
                OnColumnChanged(); 
            }
        } 
 

        ///  
        ///    Gets or sets the property that prevents modification to data
        ///       in this column.
        /// 
        [ 
            WebCategory("Behavior"),
            DefaultValue(false), 
            WebSysDescription(SR.BoundColumn_ReadOnly) 
        ]
        public virtual bool ReadOnly { 
            get {
                object o = ViewState["ReadOnly"];
                if (o != null)
                    return (bool)o; 
                return false;
            } 
            set { 
                ViewState["ReadOnly"] = value;
                OnColumnChanged(); 
            }
        }

 

        ///  
        ///  
        protected virtual string FormatDataValue(object dataValue) {
            string formattedValue = String.Empty; 

            if (!DataBinder.IsNull(dataValue)) {
                if (formatting.Length == 0) {
                    formattedValue = dataValue.ToString(); 
                }
                else { 
                    formattedValue = String.Format(CultureInfo.CurrentCulture, formatting, dataValue); 
                }
            } 

            return formattedValue;
        }
 

        ///  
        ///  
        public override void Initialize() {
            base.Initialize(); 

            boundFieldDesc = null;
            boundFieldDescValid = false;
 
            boundField = DataField;
            formatting = DataFormatString; 
        } 

 
        /// 
        /// Initializes a cell in the DataGridColumn.
        /// 
        public override void InitializeCell(TableCell cell, int columnIndex, ListItemType itemType) { 
            base.InitializeCell(cell, columnIndex, itemType);
 
            Control childControl = null; 
            Control boundControl = null;
 
            switch (itemType) {
                case ListItemType.Header:
                case ListItemType.Footer:
                    break; 

                case ListItemType.Item: 
                case ListItemType.AlternatingItem: 
                case ListItemType.SelectedItem:
                    if (DataField.Length != 0) { 
                        boundControl = cell;
                    }
                    break;
 
                case ListItemType.EditItem:
                    if (ReadOnly == true) { 
                        goto case ListItemType.Item; 
                    }
                    else { 
                        //
                        TextBox editor = new TextBox();
                        childControl = editor;
 
                        if (boundField.Length != 0) {
                            boundControl = editor; 
                        } 
                    }
                    break; 
            }

            if (childControl != null) {
                cell.Controls.Add(childControl); 
            }
 
            if (boundControl != null) { 
                boundControl.DataBinding += new EventHandler(this.OnDataBindColumn);
            } 
        }


        ///  
        /// 
        private void OnDataBindColumn(object sender, EventArgs e) { 
            Debug.Assert(DataField.Length != 0, "Shouldn't be DataBinding without a DataField"); 

            Control boundControl = (Control)sender; 
            DataGridItem item = (DataGridItem)boundControl.NamingContainer;
            object dataItem = item.DataItem;

            if (boundFieldDescValid == false) { 
                if (!boundField.Equals(thisExpr)) {
                    boundFieldDesc = TypeDescriptor.GetProperties(dataItem).Find(boundField, true); 
                    if ((boundFieldDesc == null) && !DesignMode) { 
                        throw new HttpException(SR.GetString(SR.Field_Not_Found, boundField));
                    } 
                }
                boundFieldDescValid = true;
            }
 
            object data = dataItem;
            string dataValue; 
 
            if ((boundFieldDesc == null) && DesignMode) {
                dataValue = SR.GetString(SR.Sample_Databound_Text); 
            }
            else {
                if (boundFieldDesc != null) {
                    data = boundFieldDesc.GetValue(dataItem); 
                }
                dataValue = FormatDataValue(data); 
            } 

            if (boundControl is TableCell) { 
                if (dataValue.Length == 0) {
                    dataValue = " ";
                }
                ((TableCell)boundControl).Text = dataValue; 
            }
            else { 
                Debug.Assert(boundControl is TextBox, "Expected the bound control to be a TextBox"); 
                ((TextBox)boundControl).Text = dataValue;
            } 
        }
    }
}

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