OnGlobalLayoutListener: deprecation and compatibility

一笑奈何 提交于 2019-11-26 04:48:11

问题


I have to use an OnGlobalLayoutListener object and then to remove the listener, I had a problem with deprecated methods that I resolve with following code.

protected void onCreate(Bundle savedInstanceState) {
    final LinearLayout llTotal = (LinearLayout) findViewById(R.id.mmc_ll);
    ViewTreeObserver vto = llTotal.getViewTreeObserver();
    if(vto.isAlive()){
        vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                //
                // mycode
                //
                if (Build.VERSION.SDK_INT<16) {
                    removeLayoutListenerPre16(llTotal.getViewTreeObserver(),this);
                } else {
                    removeLayoutListenerPost16(llTotal.getViewTreeObserver(), this);
                }
            } 
        });
    }
    super.onCreate(savedInstanceState);
}

@SuppressWarnings(\"deprecation\")
private void removeLayoutListenerPre16(ViewTreeObserver observer, OnGlobalLayoutListener listener){
    observer.removeGlobalOnLayoutListener(listener);
}

@TargetApi(16)
private void removeLayoutListenerPost16(ViewTreeObserver observer, OnGlobalLayoutListener listener){
    observer.removeOnGlobalLayoutListener(listener);
}

Is it correct? There is a better way to handle compatibility?

Running the code in emulator with API 10 I have the following warning in LogCat

04-24 09:30:12.565: I/dalvikvm(471): Could not find method android.view.ViewTreeObserver.removeOnGlobalLayoutListener, referenced from method com.my.project.ActivityHome.removeLayoutListenerPost16
04-24 09:30:12.565: W/dalvikvm(471): VFY: unable to resolve virtual method 2950: Landroid/view/ViewTreeObserver;.removeOnGlobalLayoutListener (Landroid/view/ViewTreeObserver$OnGlobalLayoutListener;)V

Can I ignore them of I have to fix in some way?


回答1:


I'm using this in my project:

@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
public static void removeOnGlobalLayoutListener(View v, ViewTreeObserver.OnGlobalLayoutListener listener){
    if (Build.VERSION.SDK_INT < 16) {
        v.getViewTreeObserver().removeGlobalOnLayoutListener(listener);
    } else {
        v.getViewTreeObserver().removeOnGlobalLayoutListener(listener);
    }
}

looks similar to yours. Tested on different devices (4.2.2 & 2.3.3) and it run perfectly. seems like it's the only way....If you find anything else I would like to know it. good luck




回答2:


I think the correct way is using Build.VERSION.SDK_INT and Build.VERSION_CODES:

public static void removeOnGlobalLayoutListener(View v, ViewTreeObserver.OnGlobalLayoutListener listener){
        if(Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) {
                v.getViewTreeObserver().removeGlobalOnLayoutListener(listener);
            } else {
                v.getViewTreeObserver().removeOnGlobalLayoutListener(listener);
            }
}



回答3:


    mView.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
        @Override
        public void onGlobalLayout() {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
                mView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
            } else {
                //noinspection deprecation
                mView.getViewTreeObserver().removeGlobalOnLayoutListener(this);
            }
            //
            // mycode
            //
        } 
    });



回答4:


Of course that check the Android version and call the correct method is much more prudent, but if you take a look on the Android source code you can see something interesting:

 @Deprecated
    public void removeGlobalOnLayoutListener(OnGlobalLayoutListener victim) {
        removeOnGlobalLayoutListener(victim);
    }

This code was snipped from API 18




回答5:


According to the docs:

This method was deprecated in API level 16. Use #removeOnGlobalLayoutListener instead

Works like a charm.



来源:https://stackoverflow.com/questions/16189525/ongloballayoutlistener-deprecation-and-compatibility

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