Android 动态改变对话框值

 * 动态改变对话框值
 * 关键点：onPrepareDialog方法 里面调用removeDialog(id);
 * 对话框调用执行顺序 showDialog() ->onCreateDialog() -> onPrepareDialog()-> removeDialog()
 * public final boolean showDialog(int id, Bundleargs) {
       if (mManagedDialogs == null) {
           mManagedDialogs = newSparseArray<ManagedDialog>();
       }
       ManagedDialog md = mManagedDialogs.get(id);
       if (md == null) {
           md = new ManagedDialog();
           md.mDialog = createDialog(id, null, args);
           if (md.mDialog == null) {
               return false;
           }
           mManagedDialogs.put(id, md);
       }
       
       md.mArgs = args;
       onPrepareDialog(id, md.mDialog, args);
       md.mDialog.show();
       return true;
   }
   分析showDialog方法可知
  android创建的Dialog对象统一由ManagedDialogs进行管理,如果想重新执行createDialog()方法，需先将Dialog,移出ManagedDialogs;

public class DialogActivity extends Activity implementsOnClickListener {
    privatestatic final int DIALOG_SORT_MAILS = 0x1;
    publicButton mButton;
    publicboolean flag;

   @Override
    public voidonCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.dialog_demo);

      LinearLayout layout = (LinearLayout)findViewById(R.id.nextMail);
      mButton = new Button(this);
      mButton.setText("对话框1");
      layout.addView(mButton);
      mButton.setOnClickListener(this);
      setTitle("动态改变对话框值");
    }

   @Override
    public voidonClick(View v) {
      showDialog(DIALOG_SORT_MAILS);
    }

   @Override
    public voidonPrepareDialog(int id, Dialog dialog) {
      Log.d("tag", "onPrepareDialog ");
      switch (id) {
      case (DIALOG_SORT_MAILS):
         Log.d("tag", "removeDialog ");
         removeDialog(id);
         break;
      }
    }
   
   @Override
    protectedDialog onCreateDialog(int id) {
      Log.d("tag", "onCreateDialog ");
      AlertDialog.Builder builder = newAlertDialog.Builder(
            DialogActivity.this);
      switch (id) {

      case DIALOG_SORT_MAILS:
         builder.setTitle("title");
         if (flag) {
            flag = false;
            mButton.setText("对话框1");
            builder.setSingleChoiceItems(R.array.dialog_demo1_entries,0,
                  new DialogInterface.OnClickListener() {
                     public void onClick(DialogInterface dialog, intitem) {

                        dialog.cancel();
                     }
                  });
         } else {
            flag = true;
            mButton.setText("对话框2");
            builder.setSingleChoiceItems(
                  R.array.dialog_demo2_entries, 0,
                  new DialogInterface.OnClickListener() {
                     public void onClick(DialogInterface dialog, intitem) {

                        dialog.cancel();
                     }
                  });
         }
         builder.setNegativeButton("cancel",
               new DialogInterface.OnClickListener() {
                  public void onClick(DialogInterface dialog,
                        int whichButton) {
                     dialog.cancel();
                  }
               });
         break;
      }
      AlertDialog alert = builder.create();
      return alert;

    }

}