android - 如何在不将控制权传递给 AlertDialog 类（Android 开发）的情况下从 MainActivity（类）中的 AlertDialog（类）框接收值

Question

描述：我创建了 AlertDialogBox 类，当我需要弹出对话框时，我使用 alertDialog.show()，弹出对话框将输入为 YES/NO（按钮为正和负）并保持相同的活动，但是我怎样才能得到值，即是或否，并传递用户在 mainActivity 从对话框中输入的值。尝试过：- 我尝试使用捆绑包，使用 put/get 和键值，但它返回 null 值。尝试使用全局变量但仍为空值。

谢谢您的帮助

Answer 1

Main Activity:

private void registerClickCallBack(){

    ListView list = (ListView)findViewById(R.id.starListView);
    list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        StarClassValue clickedPosition = myStar.get(position);

        Str = clickedPosition.getStarName();
        String intr = clickedPosition.getIconNum() +"";
            //Toast.makeText(MainActivity.this,Str + intr,Toast.LENGTH_LONG).show();
            sendMessage(Str,intr);


        }
    });

    list.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
        @Override
        public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
            StarClassValue click = myStar.get(position);
            String str = click.getStarName();


         dialog.show(getFragmentManager(),"Favourite");

            return false;
        }
    });
}

AlertDialog Class

public class AlertDialogFragment extends DialogFragment {

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
    Context context = getActivity();
    final AlertDialog.Builder builder = new AlertDialog.Builder(context);

    builder.setTitle("Add to Favorite").setMessage("Do you want to add this artist to your favourite list").setPositiveButton("OK", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {

        }
    }).setNegativeButton("Cancel", null);
    AlertDialog dialog = builder.create();


    return dialog;
}

}

So, how should i pass "yes" value received from AlertDialogFragment class into main activity without passing intent or control.

Answer 2

您可以通过使用接口和类的方法来做到getActivity()这getParentFragment()一点DialogFragment。

注意：我假设（因为您没有发布任何代码）您已经使用 DialogFragment 来显示 AlertDialog。

首先创建对话框和一个特殊接口，可用于将值传递给拥有Activity或Fragment：

public class MyAlertDialog extends DialogFragment implements DialogInterface.OnClickListener {

    public interface MyAlertDialogResultInterface {
        abstract void onButtonClicked(int button);
    }

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        builder.setMessage("Test message");
        builder.setPositiveButton("Ok", this);
        builder.setNegativeButton("No", this);
        return builder.create();
    }

    @Override
    public void onClick(DialogInterface dialogInterface, int button) {
        //Check if this DialogFragment is owned by a parent fragment
        if(getParentFragment() instanceof MyAlertDialogResultInterface){
            ((MyAlertDialogResultInterface) getParentFragment()).onButtonClicked(button);

        //Else check if this DialogFragment is owned by a parent activity
        } else if(getActivity() instanceof MyAlertDialogResultInterface){
            ((MyAlertDialogResultInterface) getActivity()).onButtonClicked(button);
        }
    }
}

然后将特殊界面添加到您的Activity并使用FragmentManager来显示对话框：

public class Test extends Activity implements MyAlertDialog.MyAlertDialogResultInterface {


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //Set up layout
    }

    private void showAlertDialog(){
        new MyAlertDialog().show(getFragmentManager(), "dialog-tag");
    }

    @Override
    public void onButtonClicked(int button) {
        //Do what ever you want to do
    }
}