CultureMapper.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / wpf / src / Core / CSharp / MS / Internal / TextFormatting / CultureMapper.cs / 1305600 / CultureMapper.cs
                        
                        
                            //------------------------------------------------------------------------ 
//
//  Copyright (c) Microsoft Corporation.  All rights reserved.
//
//  Description: The CultureMapper class implements static methods for mapping 
//               CultureInfo objects from WPF clients to CultureInfo objects
//               that can be used internally by text formatting code. 
// 
//  History:
//      1-30-2006 : niklasb - Created 
//
//-----------------------------------------------------------------------

using System; 
using System.Globalization;
using System.Diagnostics; 
using MS.Internal.PresentationCore; 
using System.Windows.Markup;
 
namespace MS.Internal.TextFormatting
{
    /// 
    /// Implements static methods for mapping CultureInfo objects. 
    /// 
    internal static class CultureMapper 
    { 
        /// 
        /// Returns a specific culture given an arbitrary CultureInfo, which may be null, the invariant 
        /// culture, or a neutral culture.
        /// 
        public static CultureInfo GetSpecificCulture(CultureInfo runCulture)
        { 
            // Assume default culture unless we can do better.
            CultureInfo specificCulture = TypeConverterHelper.InvariantEnglishUS; 
 
            if (runCulture != null)
            { 
                // Assign _cachedCultureMap to a local variable for thread safety. The reference assignment
                // is atomic and the CachedCultureMap class is immutable.
                CachedCultureMap cachedCultureMap = _cachedCultureMap;
                if (cachedCultureMap != null && object.ReferenceEquals(cachedCultureMap.OriginalCulture, runCulture)) 
                    return cachedCultureMap.SpecificCulture;
 
                // Unfortunately we cannot use reference comparison here because, for example, new CultureInfo("") 
                // creates an invariant culture which (being a new object) is obviously not the same instance as
                // CultureInfo.InvariantCulture. 
                if (runCulture != CultureInfo.InvariantCulture)
                {
                    if (!runCulture.IsNeutralCulture)
                    { 
                        // It's already a specific culture (neither neutral nor InvariantCulture)
                        specificCulture = runCulture; 
                    } 
                    else
                    { 
                        // Get the culture name. Note that the string expected by CreateSpecificCulture corresponds
                        // to the Name property, not IetfLanguageTag, so that's what we use.
                        string cultureName = runCulture.Name;
                        if (!string.IsNullOrEmpty(cultureName)) 
                        {
                            try 
                            { 
                                CultureInfo culture = CultureInfo.CreateSpecificCulture(cultureName);
                                specificCulture = SafeSecurityHelper.GetCultureInfoByIetfLanguageTag(culture.IetfLanguageTag); 
                            }
                            catch (ArgumentException)
                            {
                                // This exception occurs if the culture name is invalid or has no corresponding specific 
                                // culture. we can safely ignore the exception and fall back to TypeConverterHelper.InvariantEnglishUS.
                                specificCulture = TypeConverterHelper.InvariantEnglishUS; 
                            } 
                        }
                    } 
                }

                // Save the mapping so the next call will be fast if we're given the same runCulture.
                // Again, the reference assignment is atomic so this is thread safe. 
                _cachedCultureMap = new CachedCultureMap(runCulture, specificCulture);
            } 
 
            return specificCulture;
        } 

        private class CachedCultureMap
        {
            public CachedCultureMap(CultureInfo originalCulture, CultureInfo specificCulture) 
            {
                _originalCulture = originalCulture; 
                _specificCulture = specificCulture; 
            }
 
            /// 
            /// Original CultureInfo object from text formatting client; could be the invariant culture,
            /// a neutral culture, or a specific culture.
            ///  
            public CultureInfo OriginalCulture
            { 
                get { return _originalCulture; } 
            }
 
            /// 
            /// CultureInfo object to use for text formatting. This is guaranteed to be a specific (i.e.,
            /// neither neutral nor invariant) culture. It may be the same object as OriginalCulture if
            /// the latter is already a specific culture. 
            /// 
            public CultureInfo SpecificCulture 
            { 
                get { return _specificCulture; }
            } 

            private CultureInfo _originalCulture;
            private CultureInfo _specificCulture;
        } 

        private static CachedCultureMap _cachedCultureMap = null; 
    } 
}
 

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

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