如何在片段中顯示AlertDialog

Question

我是Java和Android的初學者，請大家幫忙。我想把Alert Dialog放到一個片段中，但我最終將大部分代碼複製到了下面的類中，因此兩個類包含幾乎相同的代碼。你能告訴我如何分離代碼而不在Fragment類中複製大部分代碼？

謝謝！

public class MainActivity extends Activity { 

private int mInterval = 1000; 
private Handler mHandler; 
TextView textView; 
boolean mStarted; 
final static String simple_Date_Format = "HH:mm:ss SSS"; 

public void updateStatus() { 
    long currentTimeMillis = System.currentTimeMillis(); 
    Date date = new Date(currentTimeMillis); 
    SimpleDateFormat simpleDateFormat = new SimpleDateFormat(simple_Date_Format); 
    String time_now = simpleDateFormat.format(date.getTime()); 
    textView.setText(time_now); 
} 

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

    long currentTimeMillis = System.currentTimeMillis(); 

    Calendar calendar = Calendar.getInstance(); 
    calendar.setTimeInMillis(currentTimeMillis); 

    Date date = new Date(currentTimeMillis); 
    SimpleDateFormat simpleDateFormat = new SimpleDateFormat(simple_Date_Format); 
    String time_now = simpleDateFormat.format(date.getTime()); 
    textView = (TextView) findViewById(R.id.textview); 
    textView.setText(time_now); 

    mHandler = new Handler(); 
    startRepeatingTask(); 

    Button button = (Button) findViewById(R.id.button); 
    button.setOnClickListener(new View.OnClickListener() { 

     @Override 
     public void onClick(View v) { 

      AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(
        MainActivity.this); 

      if (mStarted) { 
       alertDialogBuilder.setTitle(R.string.settings); 
       alertDialogBuilder.setMessage(R.string.stop_message); 

      } else { 
       alertDialogBuilder.setTitle(R.string.settings); 
       alertDialogBuilder.setMessage(R.string.restart_message); 
      } 

      alertDialogBuilder.setPositiveButton(R.string.click_me, 
        new DialogInterface.OnClickListener() { 

         @Override 
         public void onClick(DialogInterface dialog, int which) { 
          if (!mStarted) { 
           startRepeatingTask(); 
          } else { 
           stopRepeatingTask(); 
          } 

         } 
        }); 

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

Runnable mStatusChecker = new Runnable() { 
    @Override 
    public void run() { 

     updateStatus(); // this function can change value of mInterval. 
     mHandler.postDelayed(mStatusChecker, mInterval); 

    } 
}; 

void startRepeatingTask() { 
    mStatusChecker.run(); 
    mStarted = true; 
} 

void stopRepeatingTask() { 
    mHandler.removeCallbacks(mStatusChecker); 
    mStarted = false; 
} 

Answer 1

試試這個代碼，

import android.os.Bundle; 
import android.support.v4.app.FragmentActivity; 
import android.support.v4.app.FragmentManager; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.Button; 

public class MainActivity extends FragmentActivity { 

    Button dfragbutton; 
    Button alertdfragbutton; 
    FragmentManager fm = getSupportFragmentManager(); 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     // Get the view from activity_main.xml 
     setContentView(R.layout.activity_main); 

     // Locate the button in activity_main.xml 
     dfragbutton = (Button) findViewById(R.id.dfragbutton); 
     alertdfragbutton = (Button) findViewById(R.id.alertdfragbutton); 

     // Capture button clicks 
     dfragbutton.setOnClickListener(new OnClickListener() { 
      public void onClick(View arg0) { 
       DFragment dFragment = new DFragment(); 
       // Show DialogFragment 
       dFragment.show(fm, "Dialog Fragment"); 
      } 
     }); 

     // Capture button clicks 
     alertdfragbutton.setOnClickListener(new OnClickListener() { 
      public void onClick(View arg0) { 
       AlertDFragment alertdFragment = new AlertDFragment(); 
       // Show Alert DialogFragment 
       alertdFragment.show(fm, "Alert Dialog Fragment"); 
      } 
     }); 
    } 
} 

Answer 2

您可以使用DialogFragment來顯示警報DialogFragment有一個方法onCreateDialog中，你可以寫你彈出式警報邏輯

@Override 
    public Dialog onCreateDialog(Bundle savedInstanceState) { 

     AlertDialog.Builder builder = new AlertDialog.Builder(mContext); 

     mLayoutInflater = LayoutInflater.from(mContext); 

     rootView = mLayoutInflater.inflate(R.layout.fragment_info_dialog, null, false); 
    alertDialog = builder.create(); 
     alertDialog.setCancelable(false); 
     alertDialog.getWindow().requestFeature(Window.FEATURE_NO_TITLE); 

     return alertDialog; 
    } 

Answer 3

你可以輕鬆做到這一點與DialogFragment。只要閱讀文檔，他們也會給出如何在應用程序中實現的示例。如果你想要一個很好的例子，你可以按照這個Android DialogFragment Tutorial。

這裏是代碼做

public static class MyAlertDialogFragment extends DialogFragment { 

public static MyAlertDialogFragment newInstance(int title) { 
    MyAlertDialogFragment frag = new MyAlertDialogFragment(); 
    Bundle args = new Bundle(); 
    args.putInt("title", title); 
    frag.setArguments(args); 
    return frag; 
} 

@Override 
public Dialog onCreateDialog(Bundle savedInstanceState) { 
    int title = getArguments().getInt("title"); 

    return new AlertDialog.Builder(getActivity()) 
      .setIcon(R.drawable.alert_dialog_icon) 
      .setTitle(title) 
      .setPositiveButton(R.string.alert_dialog_ok, 
       new DialogInterface.OnClickListener() { 
        public void onClick(DialogInterface dialog, int whichButton) { 
         ((FragmentAlertDialog)getActivity()).doPositiveClick(); 
        } 
       } 
      ) 
      .setNegativeButton(R.string.alert_dialog_cancel, 
       new DialogInterface.OnClickListener() { 
        public void onClick(DialogInterface dialog, int whichButton) { 
         ((FragmentAlertDialog)getActivity()).doNegativeClick(); 
        } 
       } 
      ) 
      .create(); 
    } 
} 

製作的方法和要顯示的警告對話框中調用這個方法，在您的活動。

void showMyDialog() { 
    DialogFragment newFragment = MyAlertDialogFragment.newInstance(
     R.string.alert_dialog_two_buttons_title); 
    newFragment.show(getFragmentManager(), "dialog"); 
} 

快樂的編碼歡呼聲。