在Web应用程序之间共享asp.net资源文件

Question

我有多个需要共享资源文件的项目(.resx)已经建议将资源文件移动到单独的程序集并让Web项目引用它.有一个如何做到这一点的例子？

我是否创建了一个新的类库项目并在其中移动App_GlobalResource文件夹？我认为这不会起作用,因为为资源文件生成的代码类被标记为"内部",这意味着它们无法在此程序集之外访问.

Answer 1

在Visual Studio的属性窗口中,您应该能够将资源文件的访问修饰符设置为public.但是,您不能使用常规<%$ Resources:... %>语法访问aspx文件中的资源,因为它不支持引用程序集中的资源.我有同样的问题并通过实现自定义ExpressionBuilder解决了它,但我目前无法访问我的源代码.如果它仍然需要,我今晚可以查找代码.

编辑:好的,这就是我解决这个问题的方法:

第1步:将resx文件移动到类库中.它们不需要位于特定文件夹中.在resx文件的可视化设计器中,将"Access Modifier"(右上角)设置为"Public"

你现在应该能够

• 引用C#/ VB代码中的资源(在库中以及在Web项目中),例如,Dim myMessage As String = [Namespace.]Resources.NameOfResx.NameOfResource

• 将资源引用为aspx页面中的内联代码,例如<h1><%= [Namespace.]Resources.NameOfResx.MyTitle %></h1>.

什么不会在这一点上的工作是利用资源的表达,例如,<asp:Button runat="server" Text="<%$ Resources:NameOfResx,MyButtonText %>" />.不幸的是,你不能简单地用内联代码替换它,因为它在服务器端控件的属性内.

第2步:让我们在我们的库中创建一个自定义的ExpressionBuilder,它解释任意代码表达式.幸运的是,我们可以让强大的.net Framework类为我们完成所有工作:

Imports System.Web.Compilation
Imports System.Resources
Imports System.CodeDom

<ExpressionPrefix("Code")> _
Public Class CodeExpressionBuilder
    Inherits ExpressionBuilder

    Public Overrides Function GetCodeExpression(ByVal entry As System.Web.UI.BoundPropertyEntry, ByVal parsedData As Object, ByVal context As System.Web.Compilation.ExpressionBuilderContext) As System.CodeDom.CodeExpression
        Return New CodeSnippetExpression(entry.Expression)
    End Function
End Class

然后我们需要在web.config中注册这个ExpressionBuilder:

<system.web>
  ...
  <compilation ...>
    <expressionBuilders>
      <add expressionPrefix="Code" type="NamespaceOfYourLibrary.CodeExpressionBuilder" />
    </expressionBuilders>
  </compilation>
</system.web>

现在您应该能够执行以下操作:

<asp:Button runat="server" Text="<%$ Code:[Namespace.]Resources.NameOfResx.MyButtonText %>" />

Credit:我从Infinites Loop博客获得了CodeExpressionBuilder的想法.如果你比VB更喜欢C#,你可以看看那里的代码示例.

Answer 2

我们有一个已经开发的应用程序,我们必须拥有所有资源文件的2个副本,一个用于服务,一个用于asp.net项目,项目也依赖于<%$ Resources:NameOfResx,MyButtonText %>语法,因此更改语法是没有选择的.

一段时间后,我找到了ExpressionBuilder并提出了以下解决方案:

using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
using System.Web.Compilation;
using System.Resources;
using System.CodeDom;
using System.Reflection;

/// <summary>
/// This class allows asp.net Resource lookups to different assembly
/// </summary>
[ExpressionPrefix("Resources")]
public class ResourceExpressionBuilder : ExpressionBuilder
{
    static readonly Dictionary<string, ResourceManager> mResourceManagers = new Dictionary<string, ResourceManager>(StringComparer.OrdinalIgnoreCase);
    static ResourceExpressionBuilder()
    {
        Assembly resourceAssembly = Assembly.GetAssembly(typeof(OneTypeInResourceAssembly));
        const string suffix = ".resources";
        string assemblyName = resourceAssembly.GetName().Name;
        foreach (string resource in resourceAssembly.GetManifestResourceNames()) {
            if ((resource.EndsWith(suffix, StringComparison.OrdinalIgnoreCase))) {
                string resourceName = resource.Substring(0, resource.Length - suffix.Length);
                string resourceFriendlyName = resourceName.Substring(assemblyName.Length + 1, resourceName.Length - (assemblyName.Length + 1));
                mResourceManagers.Add(resourceFriendlyName, new ResourceManager(resourceName, resourceAssembly));
            }
        }
    }

    /// <summary>
    /// When overridden in a derived class, returns a value indicating whether the current <see cref="T:System.Web.Compilation.ExpressionBuilder" /> object supports no-compile pages.
    /// </summary>
    /// <returns>true if the <see cref="T:System.Web.Compilation.ExpressionBuilder" /> supports expression evaluation; otherwise, false.</returns>
    public override bool SupportsEvaluate {
        get { return true; }
    }

    /// <summary>
    /// When overridden in a derived class, returns an object that represents an evaluated expression.
    /// </summary>
    /// <param name="target">The object containing the expression.</param>
    /// <param name="entry">The object that represents information about the property bound to by the expression.</param>
    /// <param name="parsedData">The object containing parsed data as returned by <see cref="M:System.Web.Compilation.ExpressionBuilder.ParseExpression(System.String,System.Type,System.Web.Compilation.ExpressionBuilderContext)" />.</param>
    /// <param name="context">Contextual information for the evaluation of the expression.</param>
    /// <returns>
    /// An object that represents the evaluated expression; otherwise, null if the inheritor does not implement <see cref="M:System.Web.Compilation.ExpressionBuilder.EvaluateExpression(System.Object,System.Web.UI.BoundPropertyEntry,System.Object,System.Web.Compilation.ExpressionBuilderContext)" />.
    /// </returns>
    public override object EvaluateExpression(object target, System.Web.UI.BoundPropertyEntry entry, object parsedData, System.Web.Compilation.ExpressionBuilderContext context)
    {
        if ((parsedData != null && object.ReferenceEquals(parsedData.GetType(), typeof(string)))) {
            return GetRequestedValue(Convert.ToString(parsedData));
        }
        return base.EvaluateExpression(target, entry, parsedData, context);
    }

    /// <summary>
    /// When overridden in a derived class, returns code that is used during page execution to obtain the evaluated expression.
    /// </summary>
    /// <param name="entry">The object that represents information about the property bound to by the expression.</param>
    /// <param name="parsedData">The object containing parsed data as returned by <see cref="M:System.Web.Compilation.ExpressionBuilder.ParseExpression(System.String,System.Type,System.Web.Compilation.ExpressionBuilderContext)" />.</param>
    /// <param name="context">Contextual information for the evaluation of the expression.</param>
    /// <returns>
    /// A <see cref="T:System.CodeDom.CodeExpression" /> that is used for property assignment.
    /// </returns>
    public override System.CodeDom.CodeExpression GetCodeExpression(System.Web.UI.BoundPropertyEntry entry, object parsedData, System.Web.Compilation.ExpressionBuilderContext context)
    {
        CodeExpression[] inputParams = new CodeExpression[] { new CodePrimitiveExpression(entry.Expression.Trim()) };
        return new CodeMethodInvokeExpression(new CodeTypeReferenceExpression(this.GetType()), "GetRequestedValue", inputParams);
    }


    /// <summary>
    /// Gets the requested value.
    /// </summary>
    /// <param name="expression">The expression.</param>
    /// <returns></returns>
    public static object GetRequestedValue(string expression)
    {
        string[] parts = expression.Split(new char[] { ',' }, 2, StringSplitOptions.None);
        if ((parts.Length != 2)) {
            throw new ArgumentException("Expression must contain ,");
        }
        string resourceFile = parts[0].Trim();
        string resourceName = parts[1].Trim();
        return mResourceManagers[resourceFile].GetString(resourceName);
    }
}

替换OneTypeInResourceAssembly为包含资源的程序集中的类型.

之后你可以将以下内容添加到web.config中,它应该正常工作..

<system.web>
  <compilation>
    <expressionBuilders>
      <remove expressionPrefix="Resources" />
      <add expressionPrefix="Resources" type="Assembly.ResourceExpressionBuilder" />
    </expressionBuilders>
  </compilation>
</system.web>