将 Spinner 选定的项目从 Fragment 传递到 Activity

Question

不完全理解片段生命周期。

案例：

Click FrameLayout from Activity to move to Fragment is working.

问题：

In Fragment there are two spinners and one SubmitButton, when selected both spinner values, the clicking ofSubmitButton, should display those values from spinner back to the Activity's two Textviews . But, I am unable to do that.

我的解决方案：

I tried to use Intent, putExtras and then getExtras , but as we are in Fragment, Intent is not going to work for Fragment. Bundle also not helping.

P.S. 需要了解好的 Fragment 生命周期的人。阅读来自 Whosebug 和其他教程的许多帖子。没有找到我的意思。

不需要像 eventBus 这样的外部库

Answer 1

有两种方法可以做到这一点

1) 将 getActivity() 转换为您的 Activity 并调用特定方法并传递参数。

public class MyActivity extends AppCompatActivity {

  public void setData(String value){
        // do whatever with the data
  }
}

public class MyFragment extends Fragment{

   public void someMethod(){
     ((MyActivity)getActivity).setData(your_data);
   }
}

2) 创建一个接口并将值传递给activity.

public class MyActivity extends AppCompatActivity implements SpinnerListener{

  @Override
  public void onSpinnerItemSelected(String value){
        // do whatever with the data
  }

  public interface SpinnerListener {
    void onSpinnerItemSelected(String value);
  }
}

public class MyFragment extends Fragment {

    private SpinnerListener spinnerListener;

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        if(context instanceOf MyActivity)
           spinnerListener = ((MyActivity)context);
    }

   public void someMethod() {
      if(spinnerListener != null)
        spinnerListener.onSpinnerItemSelected(your_data); 
   }
}

注意：安全的方法是使用接口。

将 Spinner 选定的项目从 Fragment 传递到 Activity

Pass Spinner Selected Items from Fragment to Activity

android

bundle

fragment

android-intent

android-spinner