android - 为什么setVisibility会导致NullPointerException？

我有以下资料：

private OnItemSelectedListener CommentCodeListener = new OnItemSelectedListener() {
    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
        Log.i(LogTAG, "spinner selection: "+ position);
        LayoutInflater inflater=(LayoutInflater)getSystemService(LAYOUT_INFLATER_SERVICE);
        View view2=inflater.inflate(R.layout.commentdialog, null);
        CheckBox CommentPaper = (CheckBox) view.findViewById(R.id.CommentPaper);
        EditText CommentField = (EditText) view.findViewById(R.id.CommentOtherField);
        String[] arr = getResources().getStringArray(R.array.CommentCodeListValues);
        String CommentCode = arr[position];
        int CommentCodeInt = Integer.parseInt(arr[position]);
        Log.i(LogTAG, "spinner selection (int): "+ CommentCodeInt);
        CommentPaper.setVisibility(View.GONE);
        CommentField.setVisibility(View.GONE);
        if( (CommentCodeInt >= 21 && CommentCodeInt <= 31) || CommentCodeInt == 41 ) {
            Log.i(LogTAG, "set CommentPaper visible");
            CommentPaper.setVisibility(View.VISIBLE);
        }
        if( (CommentCodeInt >=22 && CommentCodeInt <=33) || (CommentCodeInt >= 35 && CommentCodeInt <=36 ) || (CommentCodeInt >= 42 && CommentCodeInt <=43 ) ) {
            Log.i(LogTAG, "set CommentPaper visible");
        }
        if( CommentCodeInt >=41 && CommentCodeInt <=43 ) {
            Log.i(LogTAG, "set CommentField visible");
            CommentField.setVisibility(View.VISIBLE);
        }

    }

    @Override
    public void onNothingSelected(AdapterView<?> arg0) {
        Log.i(LogTAG, "nothing selected");
    }

};

布局：

    <LinearLayout
           android:layout_width="wrap_content"
           android:layout_height="wrap_content"
           android:layout_gravity="center"
          android:orientation="vertical" >

        <Spinner
            android:id="@+id/CommentCode_spinner"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />

        <EditText
            android:id="@+id/MultiLineComment"
             android:layout_width="fill_parent"
         android:layout_height="wrap_content"
            android:ems="10"
            android:hint="@string/commentLabel"
            android:inputType="textMultiLine"
            android:lines="3"
            android:scrollbars="vertical" >
        </EditText>

        <EditText
            android:id="@+id/CommentOtherField"
             android:layout_width="fill_parent"
             android:layout_height="wrap_content"
            android:ems="10"
            android:hint="@string/commentLabel"
            android:visibility="visible" >
        </EditText>

        <CheckBox
            android:id="@+id/CommentPaper"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="@string/reportCheckBox"
            android:visibility="visible" />

        <Button
            android:id="@+id/AddCommentButton"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="@string/okButton" />

    </LinearLayout>

</LinearLayout>

请注意，上面的布局（commentdialog.xml）是一个对话框。
当我使用微调器选择某个对象时，将调用CommentcodeListener。当setvisibility被注释时，一切都工作。
我试过了
CheckBox CommentPaper = (CheckBox) findViewById(R.id.CommentPaper);
CheckBox CommentPaper = (CheckBox) view.findViewById(R.id.CommentPaper);
CheckBox CommentPaper = (CheckBox) view2.findViewById(R.id.CommentPaper);
但运气不好。
我错过了什么？

最佳答案

没有setinvisible不能引起npe。commentpaper/commentfield为空，您正在尝试使用它