public static Expression[] GetMethodParamSettersFromArray(this MethodInfo methodInfo, ParameterExpression arrayParams)
{
Expression[] paramSetters =
methodInfo.GetParameters().Select((param, idx) => Expression.Convert(arrayParams.CreateArrayCellAccessExpression(idx), param.ParameterType)).ToArray();
return(paramSetters);
}
// basically for method MyMethod(int i, string str) return a body of the method that would pass
// the same params as an object array
// MyMethodCall(object[] inputParams)
// {
// MyMethod((int)inputParams[0], (string) inputParams[1]);
// }
public static MethodCallExpression GetMethodCallFromParamArray
(
this MethodInfo methodInfo,
ParameterExpression inputParams,
object obj = null)
{
Expression[] paramSetters =
methodInfo.GetParameters()
.Select
(
(param, idx) =>
Expression.Convert
(
inputParams.CreateArrayCellAccessExpression(idx),
param.ParameterType)).ToArray();
Expression instanceExpression = null;
if (obj != null)
{
instanceExpression = Expression.Constant(obj);
}
MethodCallExpression methodCallExpr = Expression.Call(instanceExpression, methodInfo, paramSetters);
return(methodCallExpr);
}
public static Expression CreateAssignArrayCellExpression
(
this ParameterExpression arrayParameterExpression, // e.g. created by Expression.Parameter(typeof(object[]), "inputParams");
int cellIdx,
Expression exprToAssign)
{
var assignArrayCell =
Expression.Assign
(
arrayParameterExpression.CreateArrayCellAccessExpression(cellIdx),
exprToAssign);
return(assignArrayCell);
}