嘗試調用空對象引用錯誤上的虛擬方法'android.text.Editable android.widget.EditText.getText（）'

Question

我創建了一個DialogFragment。 對話框有一個EditText，我從對話框xml調用它。 但有錯誤：嘗試上的空對象引用調用虛擬方法android.text.Editable android.widget.EditText.getText（）'

在這個新的代碼：

AlertDialog alertDialog; 
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity()); 

和

final EditText editText = (EditText) alertDialog.findViewById(R.id.editTextPasswordDeveloper); 

我的代碼：

public class DeveloperLoginDialogFragment extends DialogFragment { 

EditText editText; 

@Override 
public Dialog onCreateDialog(Bundle savedInstanceState) { 

    final LayoutInflater inflaterDialog = getActivity().getLayoutInflater(); 

    AlertDialog alertDialog; 
    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity()); 

    alertDialog = builder.create(); 

    // final AlertDialog alertDialog = new AlertDialog.Builder(getActivity()); 
    builder.setCancelable(false); 
    builder.setView(inflaterDialog.inflate(R.layout.alertdialog_developer, null)); 
    final EditText editText = (EditText) alertDialog.findViewById(R.id.editTextPasswordDeveloper); 
    builder.setTitle("Entwickler-Login"); 
    builder.setMessage("Um dich als Entwickler zu verifizieren, gib den Entwickler-Code bitte unten ein."); 
    builder.setPositiveButton("Verifizieren", new DialogInterface.OnClickListener() { 
     @Override 
     public void onClick(DialogInterface dialog, int which) { 
      if(editText.getText().toString().equals("7846")) { 
       dialog.dismiss(); 
       Toast.makeText(getActivity().getApplicationContext(),"Erfolgreich verifiziert!", Toast.LENGTH_LONG).show(); 
      } 
     } 
    }); 
    builder.setNegativeButton("Abbrechen", new DialogInterface.OnClickListener() { 
     @Override 
     public void onClick(DialogInterface dialog, int which) { 
      Intent intent = new Intent(getActivity(), MainActivity.class); 
      startActivity(intent); 
     } 
    }); 
    return builder.create(); 
} 

}

Answer 1

問題很簡單，您正在使用編輯文本來查找視圖。你有兩個選項，要麼膨脹佈局，然後使用findViewById或使用alertDialog.findViewById（）;

試試這個。

AlertDialog.Builder builder = new AlertDialog.Builder(FeedFragment.this.getActivity()); 
    builder.setView(R.layout.layout_edit_review); 
    builder.setCancelable(true); 
    Dialog dialog = builder.create(); 
    dialog.show(); 
    TextInputEditText text_edit = (TextInputEditText) dialog.findViewById(R.id.editReview); 

嘗試類似的東西。

Answer 2

editText = (EditText) editText.findViewById(R.id.editTextPasswordDeveloper);

要調用findViewById()上editText這是空。您可能需要使用EditText editText = (EditText) alertDialog.findViewById(R.id.label_field);。請注意使用alertDialog而不是editText。