如何检查ListView完成重绘的时间?

问题描述

我有一个ListView.我更新了其适配器，并调用notifydatasetchanged().我想等到列表完成绘制，然后在列表上调用getLastVisiblePosition()来检查最后一项.

I have a ListView. I updated its adapter, and call notifydatasetchanged(). I want to wait until the list finishes drawing and then call getLastVisiblePosition() on the list to check the last item.

在notifydatasetchanged()之后立即调用getLastVisiblePosition()不起作用，因为该列表尚未完成绘制.

Calling getLastVisiblePosition() right after notifydatasetchanged() doesn't work because the list hasnt finished drawing yet.

推荐答案

希望这会有所帮助:

• 在列表视图上设置addOnLayoutChangeListener
• 致电.notifyDataSetChanged();
• 完成后，这将触发OnLayoutChangeListener
• 删除收听者

• 在更新(getLastVisiblePosition())上执行代码

• Setup a addOnLayoutChangeListener on the listview
• Call .notifyDataSetChanged();
• This will fire off the OnLayoutChangeListener once completed
• Remove the listener

• Perform code on update (getLastVisiblePosition())

mListView.addOnLayoutChangeListener(new View.OnLayoutChangeListener() {

  @Override
public void onLayoutChange(View v, int left, int top, int right, int bottom, int oldLeft, int oldTop, int oldRight, int oldBottom) {
    mListView.removeOnLayoutChangeListener(this);
    Log.e(TAG, "updated");
  }
});

mAdapter.notifyDataSetChanged();

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