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Creating a File Picker

In this post we’re going to see how to create a basic File Picker inside Unreal Engine. We’re going to use the built-in tools that the engine provides and read a text file.

[button size=”big” color=”black” link=””]Download the entire source code from my GitHub repo[/button]

Adding the required Dependencies

For this post I have created a C++ project using the 4.20 version of the engine. Then, I added the SlateCore dependency in the public module names in the <MyProject>.Build.cs file:

PublicDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine", "InputCore", "HeadMountedDisplay","SlateCore" });

Creating the file picker

Ideally, you will place the functionality of the file picker in a utility library so you can use it throughout your project. However I’ve added the code inside the character code just for demonstration purposes.

I have created two functions, one that is responsible for opening and displaying the file picker and one which is responsible for getting the contents of the selected file:

Before implementing the logic for each function, make sure to include the following header files in your class:

The reason we need to include them is so we can have access to the deskplatform code where the built-in file picker exists.

Here’s the implementation of each function:

After compiling my code, I created the following BP code to read the contents of the single file I selected:

(Click on image to enlarge in a new tab)

Here is how the file dialog looks from within the engine:

(Click on image to enlarge in a new tab)

It’s worth noting that depending on the files that you want to read your print/parse data function may differ from this post. If you want to be able to select any data type you can leave the file types string empty.

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This Post Has 12 Comments

    1. Hey, I’ve not tested yet, but I think this is because of a missing module linkage. It’s weird that there is no compile time error actually.

      I will try with
      PublicDependencyModuleNames.AddRange(new string[] { “Core”, “CoreUObject”, “Engine”, “InputCore”, “DesktopPlatform” });

      (SlateCore and HeadMountedDisplay are other modules, maybe useful for the author, but unnecessary for this tutorial)

      I will let you know if this works

  1. Is there any chance you could compile this as a plugin? I’m not familiar with C++, so this would be a huge help. Thanks!

  2. Hey, thank you for this it is really helpful! Right now I only have it working in PIE, do you know how I could modify this to work in the editor? Trying to build out some fool proof UI for getting different URI’s

  3. hey, package shipping filed error,
    UATHelper: Packaging (Windows(64位)): ERROR: Missing precompiled manifest for ‘DesktopPlatform’. This module was most likely not flagged for being included in a precompiled build – set ‘PrecompileForTargets = PrecompileTargetsType.Any;’ in to override.
    Can You know how to setting ? Thanks for you

    1. For anyone else who reads this: look into PromptUserForDirectory. Not sure if it supports multiple filepath selection, though.

  4. The DesktopPlatform module is a Developer module, the EULA version of the engine does not include Developer modules for Shipping builds. An Epic employee recommends building a custom UMG/Slate file picker that relies on IPlatformFile system instead.

  5. Very useful. Just a note, rather than declaring a specific windows handle, which didn’t seem to work for me in 4.24, let Slate handle that by using this code as the first argument in the OpenFileDialogue:


    1. Daniel, thank you a million times,

      I’ve been trying to get a viewport window handle in the editor for a couple hours now and your SlateApplication WindowHandle get worked like a charm. Cheers!

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