DialogFragment在屏幕旋轉中消失

Question

儘管我將setRetainInstance設置爲true，但屏幕旋轉後，此相當簡單的對話框將自行關閉。任何想法什麼是錯的？

public class StreetDialog extends DialogFragment { 

    public static StreetDialog newInstance(String[] values) { 
     StreetDialog f = new StreetDialog(); 
     Bundle args = new Bundle(); 
     args.putStringArray("values", values); 
     f.setArguments(args); 
     return f; 
    } 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setRetainInstance(true); 
    } 

    @Override 
    public Dialog onCreateDialog(Bundle savedInstanceState) { 

     final String[] values = getArguments().getStringArray("values"); 

     AlertDialog.Builder builder = new AlertDialog.Builder(getActivity()); 
     //build my dialog 
     return builder.create(); 
    } 

    @Override 
    public void onDestroyView() { 
     if (getDialog() != null && getRetainInstance()) 
      getDialog().setDismissMessage(null); 

     super.onDestroyView(); 
    } 
} 

Answer 1

打開對話框。如果我沒有記錯是正常行爲。我通常爲show方法提供一個標籤，當再次調用Activity的onCreate時，我查找標籤。如果片段！= null，我將其刪除，然後創建並顯示新的。在代碼中，我通常做的是：

Fragment fragment = getSupportFragmentManager().findFragmentByTag(FRAGMENT_TAG); 
if (fragment != null) { 
    getSupportFragmentManager().beginTransaction().remove(fragment).commit(); 
} 
new CustomDialogFragment().show(getSupportFragmentManager(), FRAGMENT_TAG); 

Answer 2

這是我認爲解決的最佳方式，並使用下面的方法的問題：

創建一個靜態方法來初始化一個對話框，記住，這是一個很好的做法，因爲我們總是有默認的構造函數和Bundle存儲Fragment的狀態。 在onCreateDialog方法中，使用在「構造函數方法」中傳遞的數據初始化AlertDialog。 在你的活動中，你可以實現一個接口（因爲我們不能保存它的引用，因爲它可能在旋轉設備時被破壞）。要打開對話框， 檢查它已被添加到FragmentManager中否則會顯示。

多看這裏（葡萄牙文鏈接 - BR）：http://nglauber.blogspot.com.br/2013_10_01_archive.html

public class SimpleDialog extends DialogFragment implements OnClickListener { 

    private static final String EXTRA_ID  = "id"; 
    private static final String EXTRA_MESSAGE = "message"; 
    private static final String EXTRA_TITLE = "title"; 
    private static final String EXTRA_BUTTONS = "buttons"; 
    private static final String DIALOG_TAG = "SimpleDialog"; 

    private int dialogId; 

    public static SimpleDialog newDialog(int id, 
    String title, String message, int[] buttonTexts){ 
    // Using the Bundle to save state 
    Bundle bundle = new Bundle(); 
    bundle.putInt(EXTRA_ID, id); 
    bundle.putString(EXTRA_TITLE, title); 
    bundle.putString(EXTRA_MESSAGE, message); 
    bundle.putIntArray(EXTRA_BUTTONS, buttonTexts); 

    SimpleDialog dialog = new SimpleDialog(); 
    dialog.setArguments(bundle); 
    return dialog; 
    } 

    @Override 
    public Dialog onCreateDialog(Bundle savedInstanceState) { 

    String title = getArguments() .getString(EXTRA_TITLE); 
    String message = getArguments().getString(EXTRA_MESSAGE); 
    int[] buttons = getArguments().getIntArray(EXTRA_BUTTONS); 

    AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(getActivity()); 
    alertDialogBuilder.setTitle(title); 
    alertDialogBuilder.setMessage(message); 

    switch (buttons.length) { 
     case 3: 
     alertDialogBuilder.setNeutralButton(buttons[2], this); 

     case 2: 
     alertDialogBuilder.setNegativeButton(buttons[1], this); 

     case 1: 
     alertDialogBuilder.setPositiveButton(buttons[0], this); 
    }  
    return alertDialogBuilder.create(); 
    } 

    @Override 
    public void onClick(DialogInterface dialog, int which) { 
    // Your Activity must to implements this interface 
    ((FragmentDialogInterface)getActivity()).onClick(dialogId, which); 
    } 

    public void openDialog(FragmentManager supportFragmentManager) { 

    if (supportFragmentManager.findFragmentByTag(DIALOG_TAG) == null){ 
     show(supportFragmentManager, DIALOG_TAG); 
    }  
    } 
    // Interface that was invoked by clicking the button 
    public interface FragmentDialogInterface { 
    void onClick(int id, int which); 
    } 

要在活動

public void openSimpleDialog(View v) { 
    SimpleDialog dialog = SimpleDialog.newDialog( 
    0,    // Id from dialog 
    "Alert",  // title 
    "Message",  // menssage 
    new int[]{  // texts from buttons 
     android.R.string.ok, 
     android.R.string.cancel }); 
    dialog.openDialog(getSupportFragmentManager()); 
    } 

    @Override 
    public void onClick(int id, int which) { 
    Toast.makeText(MainActivity.this, 
     "Button clicked"+ which, Toast.LENGTH_SHORT) 
     .show(); 
    }