Use of Invoke Method



Hi All,
I have gone through all the post regarding Invoke Method , but I m not getting the concept of Invoke Method.
It has Target Type-it has many items like null ,int32,string.
Target object-what is this???
Method Name:-are these method are predefined or User Defined?
Parameter : how to use this .
can someone give full concept of Invoke Method. How and where to use it.

Store multiple Datatables library classes not working properly
Invoke method
How to copy the column content in one excel sheet to the other sheet in the same excel

hi @Amarjeet

The InvokeMethod activity is another way to implement a code which is outside of the standard built-in activities. You can use this activity to invoke a method of a class. The class does not need to be part of the workflow or use any of the workflow base classes. The InvokeMethod calls a public method of a specified object or type.

InvokeMethod Properties:

MethodName: Assign the method name to this property.
TargetObject: When we want to invoke non-static methods, we need first to create an object that contains the method to execute.
TargetType: When we want to invoke static methods, we specify the type that contains the static method to execute.
GenericTypeArguments: When we want to invoke a generic method, we specify generic types in this collection.
Parameters: The parameter collection of the method to be invoked.
Result: The return value of the method execution.



Hello Akshay
I didn’t understand your explanation aswell.Please find the below scenario.

Dataset ds=new Dataset();

Datatable DT=new DataTable();


How can I acheive that in Invoke method


i think its this way

Trouble with invoke method

Thank you verymuch. I just have one more doubt

I created a datatable as

kit=new datatable(“Kitti”);
kit.tablename.tostring()—> prints correctly

but after adding to the dataset If i try to access by table name a s follow
ds.tables(“kitti”).rows.tostring this throws an error
and ds.tables(0).tablename.tostring() is printing TableName when my table name is Kitti


Below is the code

ds.tables(“kitti”).rows.tostring — Output —> System.Data.DataRowCollection
and ds.tables(0).tablename.tostring() – Output —> Kitti (unless you are creating anaother DataTable with name TableName before Kitti)


when I print ds.tables(0).tablename.tostring() – Output —> TableName
and ds.tables(“kitti”).rows.tostring-output object reference error

Are you doing anything else???


May be you did not add “dt” to the parameters in Invoke Method


If I don’t add I can’t access tables(0) aswell. But I am able to access the rows of my DT table using the Tables(0)


Try replicating my code in above image, or please attach your code.



I just found the problem If we use Build Data table after creating the new instantiation
Dt=new DataTable(“Kitti”);
and then if we print
ds.tables(0).tablename.tostring()-- Output —> TableName
otherwise its printing properly. Why is this happening???


Please add a reproduction workflow - it will make it easier for all to debug and see if it’s something wrong with the way you used the code or is there an actual bug.

Preferably include there a sample that works and the one that doesn’t - usually you’ll see what’s going on when doing those anyway.



brilliant explanation.


Hi @vvaidya/ @aksh1yadav ,

I’m reading a excel and storing the data in the datatable.
Now i need to delete a column from the datatable using invoke method.
How can i do it ? Please help me.
dbReport is the table name.



Hey @Hemanth_Gali

Please visit this link:



thank you for your reply @aksh1yadav , but my requirement is to delete column.:neutral_face:


Sorry, in hurry did not read your question well.
Check the Edited Post of mine. @Hemanth_Gali



Hi Team,

Invoke method implementation is quite simple, this is used when we try to implement something beyond our builtin activities. You can use this activity to invoke a method of a Nonstatic or Static class.

Steps for invoke Method implementation:

Example using Static Class
1 Create a .net Class Library project.
2. Create a non_static class having a non static method on it.
(Make sure that you have added the required namespace: System.Activities.presentation.Metadata and System.ComponentModel)
3 Build the project in release mode.
4 Create a nuget package and save to the the activities location in your system"UiPath\app-17.1.6522".
5 install the nuget package to the UiPath Project.
Target Type: If the class is non ststic then keep the Target type as null.
Target Object: Create a instance of the class.ex new ClassLibrary1.Validate
Method Name: Provide the method name, ex ValidateString
Pass the result to a variable, ex result
Task is complete
With Static Method

TargetType Target Type must be the class instance.




Cool! That’s exactly what I want!

But I am confused with two points:

4 Create a nuget package and save to the the activities location in your system"UiPath\app-17.1.6522".
5 install the nuget package to the UiPath Project

How can I create a Nugget Package?

And more important, How can I Install a nugget Package in UIPath Project?


Please read this post to create a Nuget Package.