android-Android調試- 刪除TextView,Button和Layout引發崩潰

Android調試- 刪除TextView,Button和Layout引發崩潰

當我點擊按鈕來刪除一個TextView ，Button 和 LinearLayout.時，程序崩潰。下面是logcat輸出，當我想在118行刪除View時就崩潰了。

  tasklayout.removeView(taskbutton);

04-15 14:35:58.222: E/AndroidRuntime(632): java.lang.NullPointerException
04-15 14:35:58.222: E/AndroidRuntime(632):  at com.com.com.addtask.deltask(addtask.java:118)
04-15 14:35:58.222: E/AndroidRuntime(632):  at com.com.com.addtask$2.onClick(addtask.java:65)
04-15 14:35:58.222: E/AndroidRuntime(632):  at android.view.View.performClick(View.java:3511)
04-15 14:35:58.222: E/AndroidRuntime(632):  at android.view.View$PerformClick.run(View.java:14105)
04-15 14:35:58.222: E/AndroidRuntime(632):  at android.os.Handler.handleCallback(Handler.java:605)

onClickListner 和 deltask void

Button delt = (Button) findViewById(R.id.btndelete1);
    delt.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            deltask(v);
        }
    });
public void deltask(View v) {

    SharedPreferences datatask;
    datatask = getSharedPreferences(filename, 0);
    int tnum = datatask.getInt("tasknumber", 1);
    int layoutnum = 1000 + tnum;
    int textviewnum = 1100 + tnum;
    int buttonviewnum = 1200 + tnum;

    LinearLayout layout = (LinearLayout) findViewById(R.id.taskll);
    LinearLayout tasklayout = (LinearLayout) findViewById(layoutnum);
    TextView tasktv = (TextView) findViewById(textviewnum);
    Button taskbutton = (Button) findViewById(buttonviewnum);

    tasklayout.removeView(taskbutton);
    tasklayout.removeView(tasktv);
    layout.removeView(tasklayout);
}

最佳回答：

估計是tasklayout為空，而tasklayout的賦值語句似乎有問題：
LinearLayout tasklayout = (LinearLayout) findViewById(layoutnum);
這個layoutnum似乎是你計算出來的一個數字，不是一個正確的資源ID，找不到對應的Layout View，tasklayout為null，就會導致tasklayout.removeView(xx)報空指針錯。