ColumnTypeConverter.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / Data / System / Data / ColumnTypeConverter.cs / 1 / ColumnTypeConverter.cs
                        

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

/* 
 */
namespace System.Data {
    using System.ComponentModel;
    using System.ComponentModel.Design.Serialization; 
    using System.Diagnostics;
    using System.Globalization; 
    using System.Data.SqlTypes; 

    ///  
    ///    Provides a type
    ///       converter that can be used to populate a list box with available types.
    /// 
    internal sealed class ColumnTypeConverter : TypeConverter { 
        private static Type[] types = new Type[] {
            typeof(Boolean), 
            typeof(Byte), 
            typeof(Byte[]),
            typeof(Char), 
            typeof(DateTime),
            typeof(Decimal),
            typeof(Double),
            typeof(Guid), 
            typeof(Int16),
            typeof(Int32), 
            typeof(Int64), 
            typeof(object),
            typeof(SByte), 
            typeof(Single),
            typeof(string),
            typeof(TimeSpan),
            typeof(UInt16), 
            typeof(UInt32),
            typeof(UInt64), 
            typeof(SqlInt16), 
            typeof(SqlInt32),
            typeof(SqlInt64), 
            typeof(SqlDecimal),
            typeof(SqlSingle),
            typeof(SqlDouble),
            typeof(SqlString), 
            typeof(SqlBoolean),
            typeof(SqlBinary), 
            typeof(SqlByte), 
            typeof(SqlDateTime),
            typeof(SqlGuid), 
            typeof(SqlMoney),
            typeof(SqlBytes),
            typeof(SqlChars),
            typeof(SqlXml) 
        };
        private StandardValuesCollection values; 
 
        // converter classes should have public ctor
        public ColumnTypeConverter() { 
        }

        /// 
        ///    Gets a value indicating whether this converter can 
        ///       convert an object to the given destination type using the context.
        ///  
        public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType) { 
            if (destinationType == typeof(InstanceDescriptor)) {
                return true; 
            }
            return base.CanConvertTo(context, destinationType);
        }
 
        /// 
        ///    Converts the given value object to the specified destination type. 
        ///  
        public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType) {
            if (destinationType == null) { 
                throw new ArgumentNullException("destinationType");
            }

            if (destinationType == typeof(string)) { 
                if (value == null) {
                    return String.Empty; 
                } 
                else {
                    value.ToString(); 
                }
            }
            if (value != null && destinationType == typeof(InstanceDescriptor)) {
                Object newValue = value; 
                if (value is string) {
                    for (int i = 0; i < types.Length; i++) { 
                        if (types[i].ToString().Equals(value)) 
                            newValue = types[i];
                    } 
                }

                if (value is Type || value is string) {
                    System.Reflection.MethodInfo method = typeof(Type).GetMethod("GetType", new Type[] {typeof(string)}); // change done for security review 
                    if (method != null) {
                        return new InstanceDescriptor(method, new object[] {((Type)newValue).AssemblyQualifiedName}); 
                    } 
                }
            } 

            return base.ConvertTo(context, culture, value, destinationType);
        }
 
        public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType) {
            if (sourceType == typeof(string)) { 
                return true; 
            }
            return base.CanConvertTo(context, sourceType); 
        }

        public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value) {
            if (value != null && value.GetType() == typeof(string)) { 
                for (int i = 0; i < types.Length; i++) {
                    if (types[i].ToString().Equals(value)) 
                        return types[i]; 
                }
 
                return typeof(string);
            }

            return base.ConvertFrom(context, culture, value); 
        }
 
        ///  
        ///    Gets a collection of standard values for the data type this validator is
        ///       designed for. 
        /// 
        public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context) {
            if (values == null) {
                object[] objTypes; 

                if (types != null) { 
                    objTypes = new object[types.Length]; 
                    Array.Copy(types, objTypes, types.Length);
                } 
                else {
                    objTypes = null;
                }
 
                values = new StandardValuesCollection(objTypes);
            } 
            return values; 
        }
 
        /// 
        ///    Gets a value indicating whether the list of standard values returned from
        ///     is an exclusive list. 
        ///  
        public override bool GetStandardValuesExclusive(ITypeDescriptorContext context) {
            return true; 
        } 

        ///  
        ///    Gets a value indicating whether this object supports a
        ///       standard set of values that can be picked from a list using the specified
        ///       context.
        ///  
        public override bool GetStandardValuesSupported(ITypeDescriptorContext context) {
            return true; 
        } 
    }
} 


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

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