Get the name of a method using an expression
x => x.DoSomething
In order to make this compilable I see only two ways:
- Go non-generic way and specify it's parameter as
Action<string, string>
- Specify
Action<string, string>
as your target delegate type by yourself:GetMethodInfo<IMyInteface>(x => new Action<string,string>(x.DoSomething))
if you are ok to go with second one, which allows you to omit arguments then you can write your GetMethodInfo
method as follows:
MemberInfo GetMethodInfo<T>(Expression<Func<T, Delegate>> expression)
{
var unaryExpression = (UnaryExpression) expression.Body;
var methodCallExpression = (MethodCallExpression) unaryExpression.Operand;
var methodInfoExpression = (ConstantExpression) methodCallExpression.Arguments.Last();
var methodInfo = (MemberInfo) methodInfoExpression.Value;
return methodInfo;
}
It works for your interface, but probably some generalization will be required to make this working with any method, that's up to you.
The following is compatible with .NET 4.5:
public static string MethodName(LambdaExpression expression)
{
var unaryExpression = (UnaryExpression)expression.Body;
var methodCallExpression = (MethodCallExpression)unaryExpression.Operand;
var methodCallObject = (ConstantExpression)methodCallExpression.Object;
var methodInfo = (MethodInfo)methodCallObject.Value;
return methodInfo.Name;
}
You can use it with expressions like x => x.DoSomething
, however it would require some wrapping into generic methods for different types of methods.
Here is a backwards-compatible version:
private static bool IsNET45 = Type.GetType("System.Reflection.ReflectionContext", false) != null;
public static string MethodName(LambdaExpression expression)
{
var unaryExpression = (UnaryExpression)expression.Body;
var methodCallExpression = (MethodCallExpression)unaryExpression.Operand;
if (IsNET45)
{
var methodCallObject = (ConstantExpression)methodCallExpression.Object;
var methodInfo = (MethodInfo)methodCallObject.Value;
return methodInfo.Name;
}
else
{
var methodInfoExpression = (ConstantExpression)methodCallExpression.Arguments.Last();
var methodInfo = (MemberInfo)methodInfoExpression.Value;
return methodInfo.Name;
}
}
Check this sample code on Ideone. Note, that Ideone does not have .NET 4.5.