Question

我遇到了导致空指针异常的问题。

问题在于我的OnCheckedChanged（）方法的结构方式。目前，基于创建时传递的字符串会膨胀不同的Dialog视图。基于此视图，可以向用户显示不同的开关。

我正在寻找一种方法来重新配置以下代码，以便它确实贯穿所有＆＃34; if语句＆＃34;和崩溃。我希望它能做类似于switch（v.getId（））+ switch结构的东西。

我正在努力避免为我的应用程序实现单独的OnCheckedChange侦听器。

任何人都知道如何重构这个以避免NullPointerException？

    @Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
    // TODO Auto-generated method stub
    if (alertDelete.isChecked()) {
        // The toggle is enabled
        permSet.add("alert_delete");
        Log.e("ALERTDELETE", "CHECKED");
    } else {
        // The toggle is disabled
        permSet.remove("alert_delete");
        Log.e("ALERTDELETE", "UNCHECKED");
    }
    if (autoCreate.isChecked()) {
        // The toggle is enabled
        permSet.add("auto_create");
        Log.e("ALERTDELETE", "CHECKED");
    } else {
        // The toggle is disabled
        permSet.remove("auto_create");
        Log.e("ALERTDELETE", "UNCHECKED");
    }
    if (autoDelete.isChecked()) {
        // The toggle is enabled
        permSet.add("auto_delete");
        Log.e("ALERTDELETE", "CHECKED");
    } else {
        // The toggle is disabled
        permSet.remove("auto_delete");
        Log.e("ALERTDELETE", "UNCHECKED");
    }
    if (autoEdit.isChecked()) {
        // The toggle is enabled
        permSet.add("auto_edit");
        Log.e("ALERTDELETE", "CHECKED");
    } else {
        // The toggle is disabled
        permSet.remove("auto_edit");
        Log.e("ALERTDELETE", "UNCHECKED");
    }

}

Answer 1

您也可以使用一种简单的方法来避免重复

private void checkAndSet(Checkable checkable, String param) {

if (checkable.isChecked()) {
            // The toggle is enabled
            permSet.add(param);
            Log.e("ALERTDELETE", "CHECKED");
        } else {
            // The toggle is disabled
            permSet.remove(param);
            Log.e("ALERTDELETE", "UNCHECKED");
        }

}

并且在每种情况下都可以致电：

checkAndSet(autoDelete, "auto_delete");

Answer 2

实现了switch（）和上面的答案。

@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
    // TODO Auto-generated method stub

    switch (buttonView.getId()) {
    case R.id.switchAlertDelete:
        if (alertDelete.isChecked()) {
            // The toggle is enabled
            permSet.add("alert_delete");
            Log.e("ALERTDELETE", "CHECKED");
        } else {
            // The toggle is disabled
            permSet.remove("alert_delete");
            Log.e("ALERTDELETE", "UNCHECKED");
        }
        break;

    case R.id.switchAutomationCreate:

        if (autoCreate.isChecked()) {
            // The toggle is enabled
            permSet.add("auto_create");
            Log.e("ALERTDELETE", "CHECKED");
        } else {
            // The toggle is disabled
            permSet.remove("auto_create");
            Log.e("ALERTDELETE", "UNCHECKED");
        }

        break;

    case R.id.switchAutomationDelete:

        if (autoDelete.isChecked()) {
            // The toggle is enabled
            permSet.add("auto_delete");
            Log.e("ALERTDELETE", "CHECKED");
        } else {
            // The toggle is disabled
            permSet.remove("auto_delete");
            Log.e("ALERTDELETE", "UNCHECKED");
        }

        break;

    case R.id.switchAutomationEdit:

        if (autoEdit.isChecked()) {
            // The toggle is enabled
            permSet.add("auto_edit");
            Log.e("ALERTDELETE", "CHECKED");
        } else {
            // The toggle is disabled
            permSet.remove("auto_edit");
            Log.e("ALERTDELETE", "UNCHECKED");
        }

        break;

    }

多个开关的问题，NullPointerException

2 个答案: