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ithaibo.github.io

admin 11月 12, 2020 0

默认ViewStub在创建时会设置为gone;

   public ViewStub(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
     super(context);
     // ...
     setVisibility(GONE);
     // ...
 }

如果手动对visibility设置为visible, invisible时，会执行inflate

 public void setVisibility(int visibility) {
     // ...
         if (visibility == VISIBLE || visibility == INVISIBLE) {
             inflate();
     // ...
 }

ViewStub在执行完inflate后，会将该ViewStub对象置为null

ViewStub 在inflate后会将stub的LayoutParams设置给inflatedView

 public View inflate() {
     // ...
     replaceSelfWithView(view, parent);
     // ...
 }

 private void replaceSelfWithView(View view, ViewGroup parent) {
     // ...
     final ViewGroup.LayoutParams layoutParams = getLayoutParams();
     if (layoutParams != null) {
         parent.addView(view, index, layoutParams);
     } else {
         parent.addView(view, index);
     }
 }

ViewStub为final，不能继承