关于枚举类型的多语言显示,其实就是Globalization的问题。解决方案当然不止一种,这里介绍一种可用性和扩展性的比较好的通用方法。
显然这里自己去实现自定义格式化,即通过IFormatable、IFormatProvider、ICustomFormatter等接口已达到Globalization有点小题大作了,而另外一个很容易想到的点是通过DiaplayMember实现显示值得自定义(对于简单Binding,例如ComboBox、ListBox等只用重载ToString就可以了)。
首先,我们希望Binding整个枚举类型的每一个值,也就是说,我们需要把这个枚举的所有值变成一个数据源,为了实现这一点,我们可以使用Enum上的helper方法Enum.GetValues(Type)来返回一个对所有值得枚举,然后依次添加到IList对象或者IListSource接口即可。
- if (!typeof(EnumType).IsEnum)
- {
- throw new NotSupportedException("Can not support type: " + typeof(EnumType).FullName);
- // It's better use resource version as below.
- // throw new NotSupportedException(SR.GetString("TYPE_NOT_SUPPORT", typeof(EnumType).FullName));
- }
- // Use Enum helper enumerator list all enum values and add to current context.
- foreach (EnumType value in Enum.GetValues(typeof(EnumType)))
- {
- //TODO: add each value to IList
- base.Add(new EnumAdapter(value));
- }
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然后,取到了值,由于我们希望自定义Binding显示,那么需要对枚举值进行封装,而在这个封装里面,我们可以实现多语言的支持。
- /// <summary>
- /// Enum value adapter, used to get values from each Cultures.
- /// </summary>
- public sealed class EnumAdapter
- {
- /**//// <summary>
- /// Storage the actual Enum value.
- /// </summary>
- private EnumType _value;
- /**//// <summary>
- /// Constructor an <see cref="EnumAdapter"/>.
- /// </summary>
- /// <param name="value">The enum value.</param>
- /// <exception cref="">
- ///
- /// </exception>
- public EnumAdapter(EnumType value)
- {
- if (!Enum.IsDefined(typeof(EnumType), value))
- {
- throw new ArgumentException(string.Format("{0} is not defined in {1}", value, typeof(EnumType).Name), "value");
- // It's better use resource version as below.
- // throw new ArgumentException(SR.GetString("ENUM_NOT_DEFINED_FMT_KEY", value, typeof(EnumType).Name), "value");
- }
- _value = value;
- }
- /**//// <summary>
- /// Gets the actual enum value.
- /// </summary>
- public EnumType Value
- {
- get { return _value; }
- }
- /**//// <summary>
- /// Gets the display value for enum value by search local resource with currrent UI lture
- /// and special key which is concated from Enum type name and Enum value name.
- /// </summary>
- /// <remarks>
- /// This would get correct display value by accessing location resource with current UI Culture.
- /// </remarks>
- public string DisplayValue
- {
- get { return SR.GetString(string.Format("{0}.{1}", typeof(EnumType).Name, _value.ToString())); }
- }
- //TODO: If you want more, please add below
- }
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至此,整个功能的框架已经完成,下面我们来看看一些细节——如何对资源读取和管理的封装:
- /// <summary>
- /// Constructor a new <see cref="SR"/>.
- /// </summary>
- internal SR()
- {
- //TODO: If you modified resource location, please update here
- this.resources = new System.Resources.ResourceManager(
- string.Concat(typeof(EnumAdapter).Namespace, ".Resource"),
- base.GetType().Assembly);
- }
- /**//// <summary>
- /// Get singleton instance.
- /// </summary>
- /// <returns>A singleton <see cref="SR"/></returns>
- private static SR GetLoader()
- {
- if (loader == null)
- {
- lock (SR.InternalSyncObject)
- {
- if (loader == null)
- {
- loader = new SR();
- }
- }
- }
- return loader;
- }
- /**//// <summary>
- /// Gets an object from resources by special key, which provided by <paramref name="name"/>.
- /// </summary>
- /// <param name="name">Resource accessed key</param>
- /// <returns>return stored object in resource. if resource not found, return <paramref name="name"/> as object.</returns>
- public static object GetObject(string name)
- {
- SR loader = GetLoader();
- if (loader == null)
- {
- return null;
- }
- try
- {
- return loader.resources.GetObject(name, Culture);
- }
- catch { }
- return name;
- }
- /**//// <summary>
- /// Gets a string from resources by special key, which provided by <paramref name="name"/>.
- /// </summary>
- /// <param name="name">Resource accessed key</param>
- /// <returns>return stored string in resource. If resource not found, retuen <paramref name="name"/> as result.</returns>
- public static string GetString(string name)
- {
- SR loader = GetLoader();
- if (loader == null)
- {
- return null;
- }
- try
- {
- return loader.resources.GetString(name, Culture);
- }
- catch { }
- return name;
- }
- /**//// <summary>
- /// Gets a formatted string from resources by special key, which provided by <paramref name="name"/> and optional parameters.
- /// </summary>
- /// <param name="name">Resource accessed key</param>
- /// <param name="args">format arguments.</param>
- /// <returns>return stored string in resource. If resource not found, use <paramref name="name"/> as formator, return the formatted string.</retur
- public static string GetString(string name, params object[] args)
- {
- SR loader = GetLoader();
- if (loader == null)
- {
- return null;
- }
- string format = name;
- try
- {
- format = loader.resources.GetString(name, Culture);
- }
- catch { }
- if ((args == null) || (args.Length <= 0))
- {
- return format;
- }
- // It's better cut long arg for formating.
- for (int i = 0; i < args.Length; i++)
- {
- string arg = args[i] as string;
- if ((arg != null) && (arg.Length > 0x400))
- {
- args[i] = arg.Substring(0, 0x3fd) + "";
- }
- }
- return string.Format(System.Globalization.CultureInfo.CurrentCulture, format, args);
- }
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OK,大功告成,有了这么一个封装,在应用里就可以简单的这么几句够搞定。
- private void Form1_Load(object sender, EventArgs e)
- {
- this.comboBox1.DataSource = new EnumDataSource<Sex>();
- this.comboBox1.DisplayMember = "DisplayValue";
- this.comboBox1.ValueMember = "Value";
- }
- public enum Sex
- {
- Male,
- Female
- }
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