536
android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an appli
錯誤產生：Java代碼
- private Context mcontext;
- @Override
- protected void onCreate(Bundle savedInstanceState) {mcontext = getApplicationContext();
- System.out.println("mcontext=" + mcontext);
- }
Java代碼
- new AlertDialog.Builder(mcontext)
- .setIcon(android.R.drawable.ic_dialog_alert)
- .setTitle("Warnning")
- .setMessage(
- "You forget to write the message. Do you want to fill out it ??")
- .setPositiveButton("Yes", positiveListener).setNegativeButton(
- "No", negativeListener).create().show();
導致報這個錯是在於new AlertDialog.Builder(mcontext)，雖然這裏的參數是AlertDialog.Builder(Context context)但我們不能使用getApplicationContext()獲得的Context,而必須使用Activity,因為隻有一個Activity才能添加一個窗體。
解決方法：將new AlertDialog.Builder(Context context)中的參數用Activity.this（Activity是你的Activity的名稱）來填充就可以正確的創建一個Dialog了。
Java代碼
- new AlertDialog.Builder(MyActivity.this)
- .setIcon(android.R.drawable.ic_dialog_alert)
- .setTitle("Warnning")
- .setMessage(
- "You forget to write the message. Do you want to fill out it ??")
- .setPositiveButton("Yes", positiveListener).setNegativeButton(
- "No", negativeListener).create().show();
最後更新：2017-04-02 06:51:50