AX / Dynamics 365 For Finance and Operations blog

In Microsoft Dynamics 365 Finance and Operations, you can add a custom lookup to a field in a form by overriding the lookup method of the control. This allows you to customize data display and enhance the user experience.

Overriding the lookup Method

To add a custom lookup, you need to override the lookup method in the form control. Below is a practical example:

1. Open the Form and Locate the Control

Open the Application Object Tree (AOT), navigate to the desired form, and locate the field where you want to add the lookup.

2. Override the lookup Method

Select the control, right-click, and choose Override Method > lookup.

In the lookup method, use the SysTableLookup class to define the reference table and the fields to display:

public void lookup()
{
    SysTableLookup sysTableLookup = SysTableLookup::newParameters(tableNum(MyTable), this);
    
    // Add the fields to be displayed in the lookup
    sysTableLookup.addLookupField(fieldNum(MyTable, MyField1));
    sysTableLookup.addLookupField(fieldNum(MyTable, MyField2));
    
    // Show the lookup
    sysTableLookup.performFormLookup();
}

3. Compile and Test the Form

Save the changes, compile the project, and test the lookup in the form to ensure it works correctly.

Conclusion

Overriding the lookup method allows you to easily customize the lookup behavior to improve data selection in the form. This technique is particularly useful when you need to restrict available values or display additional information to the user.