如何将 AlertDialog 的返回值用于布尔条件

Question

我想构建一个 java 类文件来创建 alertDialog 并为 sendSMS 返回一个布尔值。但我不知道如何从 alertDialog java 类返回一个值。所以我的函数返回 void 结果。

这是我第一个执行 alertDialog java 类的类

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

public class SMSActivity extends AppCompatActivity {

ListView mainListView;
String mainCommandStrings[] = {"Turn ON", "Turn OFF", "Parameters"};
private static final String LOG_TAG = SMSActivity.class.getSimpleName();


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_sms);

    // Array Adapter
    mainListView = findViewById(R.id.main_list_view);
    ArrayAdapter<String> arrayAdapter = new ArrayAdapter<>(this, 
            R.layout.sms_main_list_view, 
            R.id.command_text_view,
            mainCommandStrings ); 
    mainListView.setAdapter(arrayAdapter);

    mainListView.setOnItemClickListener(new AdapterView.OnItemClickListener(){
        @Override
        public void onItemClick(AdapterView parent, View view, int position, long id){
            switch (position){
                case 0: // turn on
                    Toast.makeText(getApplicationContext(),"Turn on",Toast.LENGTH_SHORT).show();
                    ConfirmSMS  confirmSMS =
                            new ConfirmSMS(getApplicationContext(), position);
                    sendTextMessage(confirmSMS, position);
                    break;
                case 1: // Turn off
                    Toast.makeText(getApplicationContext(),"Turn off",Toast.LENGTH_SHORT).show();
                    ConfirmSMS  confirmSMS1=
                            new ConfirmSMS(getApplicationContext(), position);
                    sendTextMessage(confirmSMS1, position);
                    break;
                case 2: //Setting Parameters
                    Toast.makeText(getApplicationContext(),"Parameters",Toast.LENGTH_SHORT).show();
                    intentParameter();
                    break;
                default:
                    break;
            }
        }
    });
}

private void sendTextMessage(ConfirmSMS confirmSMS, int itemPosition) {
    int position = itemPosition;
    String stat;
    if(position==0){
        stat = "SMS Sent";
    } else{
        stat = "Cancel";
    }
    Toast.makeText(getApplicationContext(),stat,Toast.LENGTH_SHORT).show();
}

private void intentParameter() {
    Log.d(LOG_TAG, "SMS Method");
    Intent parameterIntent = new Intent(this, ParameterActivity.class);
    startActivity(parameterIntent);
}

这是我的 alertDialog java 类 (ConfirmSMS)

import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.widget.Toast;

class ConfirmSMS {


ConfirmSMS(final Context applicationContext, int itemPosition){
    String stat = null;
    if(itemPosition==0){
        stat = "Turn ON";
    } else if(itemPosition==1) {
        stat = "Turn OFF";
    }

    final String condition = stat;

    AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(applicationContext);
    //Setting alert dialog
    alertDialogBuilder.setTitle("Confirmation"); // set judul
    alertDialogBuilder.setMessage("Are you sure to "+ condition+ " the AC?"); 
    alertDialogBuilder.setCancelable(true);

    alertDialogBuilder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            Toast.makeText(applicationContext,
                    "Send instruction to "+condition+" the AC",
                    Toast.LENGTH_SHORT).show();
        }
    });

    alertDialogBuilder.setNegativeButton("No", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            Toast.makeText(applicationContext,
                    "Cancel",
                    Toast.LENGTH_SHORT).show();
        }
    });

    AlertDialog alertDialog = alertDialogBuilder.create();
    alertDialog.show();
}
}

Answer 1

重构您的代码，这样您就不需要其他类来创建 AlertDialog。重新组织您的代码以将其全部保留在 Activity 中，以便您可以从 AlertBuilder 上的操作中访问方法 sendTextMessage。 像这样的：

import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

public class SMSActivity extends AppCompatActivity {

ListView mainListView;
String mainCommandStrings[] = {"Turn ON", "Turn OFF", "Parameters"};
private static final String LOG_TAG = SMSActivity.class.getSimpleName();

private boolean myBoolean;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_sms);

    // Array Adapter
    mainListView = findViewById(R.id.main_list_view);
    ArrayAdapter<String> arrayAdapter = new ArrayAdapter<>(this,
            R.layout.sms_main_list_view,
            R.id.command_text_view,
            mainCommandStrings);
    mainListView.setAdapter(arrayAdapter);

    mainListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView parent, View view, final int position, long id) {
            String stat = null;
            switch (position) {
                case 0: // turn on
                    Toast.makeText(getApplicationContext(), "Turn on", Toast.LENGTH_SHORT).show();
                    stat = "Turn ON";
                    break;
                case 1: // Turn off
                    Toast.makeText(getApplicationContext(), "Turn off", Toast.LENGTH_SHORT).show();
                    stat = "Turn ON";
                    break;
                case 2: //Setting Parameters
                    Toast.makeText(getApplicationContext(), "Parameters", Toast.LENGTH_SHORT).show();
                    intentParameter();
                    break;
                default:
                    break;
            }
            final String condition = stat;
            if(condition != null){
                AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(getApplicationContext());
                //Setting alert dialog
                alertDialogBuilder.setTitle("Confirmation"); // set judul
                alertDialogBuilder.setMessage("Are you sure to "+ condition+ " the AC?");
                final AlertDialog.Builder builder = alertDialogBuilder.setCancelable(true);

                alertDialogBuilder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        Toast.makeText(getApplicationContext(),
                                "Send instruction to "+condition+" the AC",
                                Toast.LENGTH_SHORT).show();
                        //Here is where you execute sendTextMessage 
                        //passing the param from the AlertDialog
                        sendTextMessage(position);
                    }
                });

                alertDialogBuilder.setNegativeButton("No", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        Toast.makeText(getApplicationContext(),
                                "Cancel",
                                Toast.LENGTH_SHORT).show();
                    }
                });

                AlertDialog alertDialog = alertDialogBuilder.create();
                alertDialog.show();
            }
        }
    });
}

private void sendTextMessage(int itemPosition) {
    int position = itemPosition;
    String stat;
    if (position == 0) {
        stat = "SMS Sent";
    } else {
        stat = "Cancel";
    }
    Toast.makeText(getApplicationContext(), stat, Toast.LENGTH_SHORT).show();
}

private void intentParameter() {
    Log.d(LOG_TAG, "SMS Method");
    Intent parameterIntent = new Intent(this, ParameterActivity.class);
    startActivity(parameterIntent);
}