TwoWayBinding on a Slider with Min Value not set to 0 fails about unity-weld HOT 4 CLOSED

I had a go of modifying the slider example from our example project to use min values other than 0.

What I observed was that moving the sliders worked as expected, and I could move one slider beyond the minimum value of the other one fine.

I noticed that when I changed the value the slider was bound to externally to a value outside the range of the slider, the property would be set once with that value, then immediately again with the min value of the slider. Is this the issue you're talking about?

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Thanks for the in depth tests. No, that's not the issue I'm having. I just did some more tests and I'm having a hard time debugging it.
The problem is, that this problem doesn't show up in the UI. Like your example, my slider is working fine and if I connect a Text object to it, it shows the correct value all the time.

The thing is though, in my "set" method for this property I'm also calling PlayerPrefs.SetInt("DayOfYear", value). When my application is restarted, I'm reading that value back from the PlayerPrefs. And THAT'S how I discovered the problem. Somehow, my property's "set" method is called with an incorrect value, and somehow at the same time the UI doesn't reflect that wrong value. I want the range to be [1, 365], but that results in PlayerPrefs always storing the value 1 (well, it's the last value that's written). If I set the range of the slider to [0, 365], everything works as expected.

Since this incorrect value seems to come from Unity's side, I'm not sure there's anything you could do really. These are the two consecutive calls I get:

That last zero gets changed into a 1 later, because it's outside the range. As you might notice, the localCursor value for the second call is a lot more to the left, compared to the first call. I noticed that this is something that happens during debugging, because I moved my mouse pointer to my screen on the left after the first breakpoint was hit. So at one point I thought that this whole problem might only occur during debugging, but that's not the case as I can see by the value that is stored by the PlayerPrefs call.

So, right now I've just decided to set the range to [0, 365] and live with it. It's pretty confusing to me why the call with this wrong value happens and how it could be that the UI is NOT showing this wrong value. Maybe I'm doing something wrong, but my code is pretty simple so I don't think it's me:

[Binding]
public int DayOfYear
{
    get
    {
        return dayOfYear;
    }
    set
    {
        if (dayOfYear == value)
        {
            return; // No change.
        }

        dayOfYear = value;
        PlayerPrefs.SetInt("DayOfYear", value);
        OnPropertyChanged("DayOfYear");
    }
}

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Hmm looks like this is the just way Unity UI works. I'll close this for now because it looks like you have a workaround and I'm not sure what we could do from our side to fix it, but let us know if you have an idea how we could better handle it.

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Fair enough. I also noticed that when I place an OnPropertyChanged call somewhere in my code to trigger a UI update, besides the "get" method, the "set" method is also called by Unity. Pretty strange and wrong behavior in my opinion.

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