/// <summary>
/// Uses reflection to dynamically invoke a method,
/// throwing an exception if it is not
/// implemented on the target object.
/// </summary>
/// <param name="obj">
/// Object containing method.
/// </param>
/// <param name="info">
/// MethodInfo for the method.
/// </param>
/// <param name="parameters">
/// Parameters to pass to method.
/// </param>
public static object CallMethod(object obj, MethodInfo info, params object[] parameters)
{
DynamicMethodHandle mh = GetCachedMethod(obj, info, parameters);
if (mh == null || mh.DynamicMethod == null)
{
throw new NotImplementedException(info.Name + " not implemented.");
}
return(CallMethod(obj, mh, parameters));
}
/// <summary>
/// Uses reflection to dynamically invoke a method
/// if that method is implemented on the target object.
/// </summary>
/// <param name="obj">
/// Object containing method.
/// </param>
/// <param name="method">
/// Name of the method.
/// </param>
/// <param name="parameters">
/// Parameters to pass to method.
/// </param>
public static object CallMethodIfImplemented(object obj, string method, params object[] parameters)
{
DynamicMethodHandle mh = GetCachedMethod(obj, method, parameters);
if (mh == null || mh.DynamicMethod == null)
{
return(null);
}
return(CallMethod(obj, mh, parameters));
}
/// <summary>
/// Uses reflection to dynamically invoke a method,
/// throwing an exception if it is not implemented
/// on the target object.
/// </summary>
/// <param name="obj">
/// Object containing method.
/// </param>
/// <param name="methodHandle">
/// MethodHandle for the method.
/// </param>
/// <param name="parameters">
/// Parameters to pass to method.
/// </param>
private static object CallMethod(object obj, DynamicMethodHandle methodHandle, params object[] parameters)
{
object result = null;
DynamicMemberMethod method = methodHandle.DynamicMethod;
object[] inParams = null;
if (parameters == null)
{
inParams = new object[] { null }
}
;
else
{
inParams = parameters;
}
if (methodHandle.HasFinalArrayParam)
{
int pCount = methodHandle.MethodParamsLength;
// last param is a param array or only param is an array
int extras = inParams.Length - (pCount - 1);
// 1 or more params go in the param array
// copy extras into an array
object[] extraArray = GetExtrasArray(extras, methodHandle.FinalArrayElementType);
Array.Copy(inParams, extraArray, extras);
// copy items into new array
var paramList = new object[pCount];
for (int pos = 0; pos <= pCount - 2; pos++)
{
paramList[pos] = parameters[pos];
}
paramList[paramList.Length - 1] = extraArray;
// use new array
inParams = paramList;
}
try
{
result = methodHandle.DynamicMethod(obj, inParams);
}
catch (Exception ex)
{
throw new CallMethodException(methodHandle.MethodName + " method call failed.", ex);
}
return(result);
}
private static DynamicMethodHandle GetCachedMethod(object obj, MethodInfo info, params object[] parameters)
{
var key = new MethodCacheKey(obj.GetType().FullName, info.Name, GetParameterTypes(parameters));
DynamicMethodHandle mh = null;
if (_methodCache.TryGetValue(key, out mh))
return mh;
lock (_methodCache)
{
if (!_methodCache.TryGetValue(key, out mh))
{
mh = new DynamicMethodHandle(info, parameters);
_methodCache.Add(key, mh);
}
}
return mh;
}
private static DynamicMethodHandle GetCachedMethod(object obj, MethodInfo info, params object[] parameters)
{
var key = new MethodCacheKey(obj.GetType().FullName, info.Name, GetParameterTypes(parameters));
DynamicMethodHandle mh = null;
if (_methodCache.TryGetValue(key, out mh))
{
return(mh);
}
lock (_methodCache)
{
if (!_methodCache.TryGetValue(key, out mh))
{
mh = new DynamicMethodHandle(info, parameters);
_methodCache.Add(key, mh);
}
}
return(mh);
}
/// <summary>
/// Uses reflection to dynamically invoke a method,
/// throwing an exception if it is not implemented
/// on the target object.
/// </summary>
/// <param name="obj">
/// Object containing method.
/// </param>
/// <param name="methodHandle">
/// MethodHandle for the method.
/// </param>
/// <param name="parameters">
/// Parameters to pass to method.
/// </param>
private static object CallMethod(object obj, DynamicMethodHandle methodHandle, params object[] parameters)
{
object result = null;
DynamicMemberMethod method = methodHandle.DynamicMethod;
object[] inParams = null;
if (parameters == null)
inParams = new object[] { null };
else
inParams = parameters;
if (methodHandle.HasFinalArrayParam)
{
int pCount = methodHandle.MethodParamsLength;
// last param is a param array or only param is an array
int extras = inParams.Length - (pCount - 1);
// 1 or more params go in the param array
// copy extras into an array
object[] extraArray = GetExtrasArray(extras, methodHandle.FinalArrayElementType);
Array.Copy(inParams, extraArray, extras);
// copy items into new array
var paramList = new object[pCount];
for (int pos = 0; pos <= pCount - 2; pos++)
paramList[pos] = parameters[pos];
paramList[paramList.Length - 1] = extraArray;
// use new array
inParams = paramList;
}
try
{
result = methodHandle.DynamicMethod(obj, inParams);
}
catch (Exception ex)
{
throw new CallMethodException(methodHandle.MethodName + " method call failed.", ex);
}
return result;
}
