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I try to get a FrameLayout's height in onGlobalLayout(), this piece of code is in the onCreate() method:

final FrameLayout layout = (FrameLayout)findViewById(R.id.detail_frame);
        ViewTreeObserver vto = layout.getViewTreeObserver();
        vto.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                layout.getViewTreeObserver().removeOnGlobalLayoutListener (this);
                ViewGroup.LayoutParams lPF = layout.getLayoutParams();
                int gg = layout.getHeight();
                int hh = lPF.height;
The XML file:
<FrameLayout
                android:orientation="vertical"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:id="@+id/detail_frame">
</FrameLayout>
but when I was debugging, 'gg' got the right height value, 'hh' got -1. I'm doing this because I want to set the layout's height. How can I get the right value of LayoutParams? 
                That is the "right" value. It corresponds to MATCH_PARENT, which means "make this the same as the parent's height, whatever that may be". The actual value won't be known until layout, at which point you can use getHeight(), like you have. The LayoutParams#height field won't be changed to reflect that value, though. It will remain at MATCH_PARENT. You can set exact values for that yourself, however, if that's what you mean to do.
– Mike M.
                Jun 4, 2018 at 9:42
                I'm not sure what you mean. That's what you're already doing with the OnGlobalLayoutListener.
– Mike M.
                Jun 4, 2018 at 9:56
You already did, onGlobalLayout is called when the view finishes laying out, that's why getHeight return non-zero pixel in height. If it's not drawn yet, getHeight will return 0
  
How can I get the right value of LayoutParams?
Nothing is wrong here, it's a right value. You get -1 from LayoutParams.height because it's MATCH_PARENT placeholder value, just like WRAP_CONTENT = -2. Android read this layout params value, then calculate the real size in pixel, which will be the value you get when calling getHeight.
  
I'm doing this because I want to set the layout's height 
Just set the height value to the LayoutParams: layout.getLayoutParams().height = 100
        
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