How to disable Gameobjects for Screenshot capturing in Unity on Android?-CodePudding

I have a simple goal for my Unity application running on Android: create a function, which disables my GUI, creates a screenshot, stores the image and enables the GUI again.

This is my current code:

The whole UI is stored in a GameObject which my handler class holds as property:

private bool makeScreenshotFlag;
public GameObject UserInterface;

makeScreenshotFlag above is used in the Update function:

// Update is called once per frame
void Update()
{
    if (makeScreenshotFlag)
    {
        // Working with this flag is necessary, 
        // since we need to wait for the next frame, 
        // where the gui is not visible;
        MakeScreenShot();
    }
}

If the corresponding button gets pressed I fire the following Method:

public void OnCreateScreenshotButtonPressed()
{
    UserInterface.SetActive(false);
    makeScreenshotFlag = true;
}

And at last the method for the screenshot itself:

private void MakeScreenShot()
{
    if (UserInterface.activeSelf) return; // wait for the next frame if the gui is still active

    try
    {
        string filename = "screenshot_"   DateTime.Now.ToString("HH-mm-ss--dd-MM-yyyy")   ".png";
        ScreenCapture.CaptureScreenshot(filename);
    }
    catch (Exception e)
    {
        DebugHelper.NewLog = "Error capturing screenshot: "   e.Message;
    }
    finally
    {
        makeScreenshotFlag = false;
        UserInterface.SetActive(true);
    }
}

In theory this should work, however the documentation for ScreenCapture.CaptureScreenshot() states the following:

The CaptureScreenshot returns immediately on Android. The screen capture continues in the background. The resulting screen shot is saved in the file system after a few seconds.

In practice this means, when my screenshot is made, the GUI is already enabled again. So far I couldn't find any event or similar to get notified as soon as the screenshot is made. The only thing I can think of is to store the screenshot filename and check if the file exists each frame after the screenshot is started.

Is there any other, more practical way?

CodePudding user response：

Most probably, you are capturing the frame with UI itself. It's better to wait till the end of the frame using Coroutine.

public IEnumerator MakeScreenShot()
{
    // Wait till the last possible moment before screen rendering to hide the UI
    yield return null;

    // Disable UI       
    UserInterface.SetActive(false);

    // Wait for screen rendering to complete
    yield return new WaitForEndOfFrame();

    // Take screenshot
    Application.CaptureScreenshot("screenshot.png");

    // Show UI after we're done
    UserInterface.SetActive(true);
}