如何动态更新Spinner？ [英] How to update an Spinner dynamically correctly?

问题描述

我有一个带有自定义适配器的旋转器，显示数据库中的对象。
当对象列表更改时，我使用列表创建一个新的适配器并将其应用到微调框上。之后选择了第一个项目，所以我试过这个：

  //选择第5项
 int pos = spinner。 getSelectedItemPosition（）; 
 spinner.setAdapter（newAdapter）; 
 //第0项选择
 spinner.setSelectedItem（pos）; 
 //选择第5项
  

但GUI仍然显示第一项？ / p>

spinner.invalidate（）没有帮助。

解决方案

解决：我想主要的问题是自定义微调适配器。这样可以正常工作

  if（spinner.getCount（）> 0）{
 pos = spinner.getSelectedItemPosition ）; 
} 
 MySpinnerAdapter adapter = new MySpinnerAdapter（context，myNewObjects）; 
 spinner.setAdapter（adapter）; 
 spinner.setSelection（pos）; //需要
 adapter.notifyDataSetChanged（）; 
  

I have a spinner with a custom adapter displaying objects from a database. When the object list changed I create a new adapter with the List and apply it on the spinner. Afterwards the first item is selected, so I tried this:

// 5th item selected
int pos = spinner.getSelectedItemPosition();
spinner.setAdapter(newAdapter);
// 0th item selected
spinner.setSelectedItem(pos);
// 5th item is selected

But the GUI does still show the first item?

spinner.invalidate() did not help.

Is this the correct way to achieve what I want? I really could not find any information on this behavior.

解决方案

Solved: I guess the main problem was the custom spinner adapter. This works fine now

if (spinner.getCount() > 0) {
    pos = spinner.getSelectedItemPosition();
}
MySpinnerAdapter adapter = new MySpinnerAdapter(context, myNewObjects);
spinner.setAdapter(adapter);
spinner.setSelection(pos); // needed
adapter.notifyDataSetChanged();

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