To edit an API as a C# project with external programs (for example, Visual Studio), perform the following steps:
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Link your API Designer project with a new or existing C# project. 
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Edit the C# project in an external program. 
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Open the C# project again in API Designer and save it in the API project. 
To link the API Designer project with a C# project
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In the menu bar, click View > Home. 
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On the start page, expand the C# development pane. 
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In the C# development pane, perform one of the following actions: - 
To export and link the API Designer project as a new C# project, click Export C# project. Navigate to the folder where you want to export the content of your API Designer project as a C# project and click OK. 
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To link the API Designer project with an existing project, click Load C# project. 
 The API Designer is linked with the C# project. 
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To edit the C# project in an external program
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In the menu bar, click View > Home. 
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On the start page, expand the C# development pane. 
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In the C# development pane, click Project file: <path to C# project>. The project opens in the program that the project file is linked with. TIP: To open the project folder directly, click Open corresponding folder. 
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Edit the project in the external program. For example, you can create, change, or delete API files. 
To save changes back to the API Designer project
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Open the API Designer. 
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In the menu bar, click View > Home. 
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On the start page, expand the C# development pane. 
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In the C# development pane, click Synchronize C# project with base. You now see the objects that you have changed outside the API Designer. 
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In the list, next to the changed objects, select the actions that you want to perform for the API Designer project. Status message Description Actions New C# file A new API file was created in the C# project. Add API file: Adds the C# file that you created in the external program to yourAPI Designer project as an API file. Delete file: Deletes the C# class in the C# project. New API file A new API file was created in the API Designer Sharp project. Add C# file: Adds the API file that you created in the API Designer to your C# project as a C# file. Delete API file: Deletes the API file in the API Designer project. API file is newer An API file was modified in the API Designer project. Update: Transfers the changes to the API file from the API Designer project into the C# project. Revert changes: Reverses the changes that you made in your API Designer project in the API file. C# file is newer An API file was modified in the C# project. Update: Transfers the changes to the API file from the C# project into the API Designer project. Revert changes: Reverses the changes that you made in your C# project in the API file. 
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Select the check box next to the objects for which the selected actions should be performed. TIP: To quickly select or deselect all objects, select the Select all/deselect all check box above the list. 
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Click (Apply selected actions). 
