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//------------------------------------------------------------------------------
// <copyright file="DataSourceCacheDurationConverter.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//------------------------------------------------------------------------------
namespace System.Web.UI {
using System;
using System.Collections;
using System.ComponentModel;
using System.ComponentModel.Design.Serialization;
using System.Globalization;
using System.Reflection;
using System.Security.Permissions;
using System.Web.Util;
/// <devdoc>
/// Converts a cache duration such as an integer or the text "Infinite" to a cache duration, where "Infinite" implies zero (0).
/// </devdoc>
public class DataSourceCacheDurationConverter : Int32Converter {
private StandardValuesCollection _values;
public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType) {
if (sourceType == typeof(string)) {
return true;
}
else {
return base.CanConvertFrom(context, sourceType);
}
}
public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value) {
if (value == null)
return null;
string stringValue = value as string;
if (stringValue != null) {
string textValue = stringValue.Trim();
if (textValue.Length == 0) {
return 0;
}
if (String.Equals(textValue, "infinite", StringComparison.OrdinalIgnoreCase)) {
return 0;
}
}
return base.ConvertFrom(context, culture, value);
}
public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType) {
if (destinationType == typeof(string)) {
return true;
}
else {
return base.CanConvertTo(context, destinationType);
}
}
public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType) {
if ((value != null) && (destinationType == typeof(string)) && ((int)value == 0)) {
return "Infinite";
}
else {
return base.ConvertTo(context, culture, value, destinationType);
}
}
public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context) {
if (_values == null) {
object[] values = new object[] { 0 };
_values = new StandardValuesCollection(values);
}
return _values;
}
public override bool GetStandardValuesExclusive(ITypeDescriptorContext context) {
return false;
}
public override bool GetStandardValuesSupported(ITypeDescriptorContext context) {
return true;
}
}
}
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