Question

我在静态函数findViewById中发现错误。

我的职能是 -

public static void onYearSelect() {

    Spinner yearSelector;
    String yearName;
    yearSelector = (Spinner) findViewById(R.id.year_submit);
    yearName = yearSelector.getSelectedItem().toString();

}

有没有办法解决这个错误！

我可以将yearName中的Spinner值存储为String

Answer 1

您需要在函数内添加视图作为参数。

public static void onYearSelect(View view) {

    Spinner yearSelector;
    yearSelector = (Spinner) view.findViewById(R.id.year_submit);
    yearName = yearSelector.getSelectedItem().toString();

}

The view which contains your layout data。

当您调用该函数时，在onYearSelect(rootView)添加rootView具有布局视图。

编辑1：

这是什么视图？

A View in Android is a widget that displays something. Buttons, listviews, imageviews, etc. are all subclasses of View. When you say "change view" I assume you mean change the layout by using setContentView(). This usually only needs to be done once per activity. An Activity is basically what you are referring to as a screen.

您可以阅读更多here。

Answer 2

在spinner对象上设置setOnItemSelectedListener，在onItemSelected（）内设置yearName的值。如下所示，

yearSelector.setOnItemSelectedListener(new OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parentView, View selectedItemView, int position, long id) {
 String yearName = parentView.getItemAtPosition(position).toString()
}

@Override
public void onNothingSelected(AdapterView<?> parentView) {
    // your code here
}});

findViewById无法在静态函数中工作

2 个答案: