是否有可能制作一个通用方法，它可以用 System.Data.Linq.Mapping.FunctionAttribute 代替三个方法？

Question

我的 datacontext 类中有三个方法，它们都调用具有不同行为的略有不同的存储过程；追加、更新、覆盖。然而，这三种方法本质上具有相同的代码。唯一的区别是装饰方法的System.Data.Linq.Mapping.FunctionAttribute 的“名称”属性。

[Function(Name = "import.usp_MyData_ProcessImportAppend", IsComposable = false)]

或

[Function(Name = "import.usp_MyData_ProcessImportUpdate", IsComposable = false)]

或

[Function(Name = "import.usp_MyData_ProcessImportOverwrite", IsComposable = false)]

本质上它们看起来都与此相似

/// <summary>
/// Processes the import.
/// </summary>
/// <param name="loadId">The load id.</param>
/// <exception cref="System.ArgumentNullException">loadId</exception>
[Function(Name = "import.usp_MyData_ProcessImportAppend", IsComposable = false)]
public Int32 ProcessGradingImport(string loadId)
{
    // Validate parameter
    if (String.IsNullOrEmpty(loadId)) throw new ArgumentNullException("loadId");

    // Initialise the result and the procedure parametes
    Int32 result = 0;
    object[] parameters = { loadId };

    // Call the procedure, and return the result
    IExecuteResult executionResult = ExecuteMethodCall(this, (MethodInfo)(MethodBase.GetCurrentMethod()), parameters);
    if (executionResult != null) result = (int)executionResult.ReturnValue;
    return result;
}

有什么方法可以编写一个泛型方法来传递要映射到的函数名吗？谢谢。

更新 因此，基于 Ron 和 Alex 的出色解决方案，我现在有了

/// <summary>
/// Process imports.
/// </summary>
/// <param name="methodInfo">The method information.</param>
/// <param name="loadId">The load identifier.</param>
/// <returns></returns>
/// <exception cref="System.ArgumentNullException">loadId</exception>
private Int32 ProcessImport(MethodInfo methodInfo, string loadId)
{
    // Validate parameter
    if (String.IsNullOrEmpty(loadId)) throw new ArgumentNullException("loadId");

    // Initialise the result and the procedure parametes
    Int32 result = 0;
    object[] parameters = { loadId };

    // Call the procedure, and return the result
    IExecuteResult executionResult = ExecuteMethodCall(this, methodInfo, parameters);
    if (executionResult != null) result = (int)executionResult.ReturnValue;
    return result;
}

在装饰函数中调用...

[Function(Name = "common.usp_MyData_ProcessImportAppend", IsComposable = false)]
public Int32 ProcessImportAddNewUpdateCurrentOnly(string loadId)
{
    return ProcessImport((MethodInfo)(MethodBase.GetCurrentMethod()), loadId);
}

Answer 1

我会为代码重用做这样的事情：

[Function(Name = "import.usp_MyData_ProcessImportAppend", IsComposable = false)]
public Int32 ProcessGradingImport(string loadId)
{
    ProcessLoadId(loadId, (MethodInfo)(MethodBase.GetCurrentMethod(), new object[] { loadId });
}

[Function(Name = "import.usp_MyData_ProcessImportUpdate", IsComposable = false)]
public Int32 ProcessGradingImportUpdate(string loadId)
{
    ProcessLoadId(loadId, (MethodInfo)(MethodBase.GetCurrentMethod(), new object[] { loadId });
}

[Function(Name = "import.usp_MyData_ProcessImportOverwrite", IsComposable = false)]
public Int32 ProcessGradingImportOverwrite(string loadId)
{
    ProcessLoadId(loadId, (MethodInfo)(MethodBase.GetCurrentMethod(), new object[] { loadId });
}

public Int32 ProcessLoadId(string loadId, MethodInfo method, object[] parameters)
{
    // Validate parameter
    if (String.IsNullOrEmpty(loadId)) throw new ArgumentNullException("loadId");

    // Initialise the result and the procedure parametes
    Int32 result = 0;

    // Call the procedure, and return the result
    IExecuteResult executionResult = ExecuteMethodCall(this, methodInfo, parameters);
    if (executionResult != null) result = (int)executionResult.ReturnValue;
    return result;
}

不幸的是，从 C# 5.0 开始，没有办法满足您的要求。该属性不允许每个函数有多个副本，因此您所能做的就是分解重用代码并将其分解一点。它可能会进一步减少以删除参数对象，因为它只是从loadId 构造的。

Answer 2

有什么办法可以写一个泛型方法，其中函数名 映射到被传入？

如果您指的是通用、“可重复使用”或“样板”：是的：

private Int32 MyBoilerplateImpl(string IdArgument, string argumentName, MethodInfo method)
{
    // Validate parameter
    if (String.IsNullOrEmpty(IdArgument)) throw new ArgumentNullException(argumentName);

    // Initialise the result and the procedure parameters
    Int32 result = 0;
    object[] parameters = { IdArgument};

    // Call the procedure, and return the result
    IExecuteResult executionResult = ExecuteMethodCall(this, method, parameters);
    if (executionResult != null) 
        result = (int)executionResult.ReturnValue;
    return result;
}

然后像这样调用它：

[Function(Name = "import.usp_MyData_ProcessImportAppend", IsComposable = false)]
public Int32 ProcessGradingImport(string loadId) 
{
    MyBoilerplateImpl(loadId, "loadId", (MethodInfo)(MethodBase.GetCurrentMethod());
}