Question

我得到了一个用值添加的子菜单，然后我想通过读取包含当前视图模式的currentViewMode变量来设置它们......下面的代码必须检查第一个，但它没有。请指教。

private enum ViewMode
{
    NORMAL,
    SATELLITE,
    HYBRID
}
private ViewMode currentViewMode = ViewMode.NORMAL;

private final int  SUB_MENU_GROUP = 1;
private final int SUB_MENU_ITEM_NORMAL = 1;
private final int SUB_MENU_ITEM_SATELLITE = 2;
private final int SUB_MENU_ITEM_HYBRID = 3;

public boolean onCreateOptionsMenu(Menu menu) {
    SubMenu sub = menu.addSubMenu(0, 1, 0, R.string.menu_mapwindow_viewmode).setIcon(R.drawable.ic_menu_refresh);
    sub.add(SUB_MENU_GROUP, SUB_MENU_ITEM_NORMAL, Menu.NONE, this.getString(R.string.mapwindow_viewmode_normal));
    sub.add(SUB_MENU_GROUP, SUB_MENU_ITEM_SATELLITE, Menu.NONE, this.getString(R.string.mapwindow_viewmode_satellite));
    sub.add(SUB_MENU_GROUP, SUB_MENU_ITEM_HYBRID, Menu.NONE, this.getString(R.string.mapwindow_viewmode_hybrid));
    sub.setGroupCheckable(SUB_MENU_GROUP, true, true);

    if (this.currentViewMode == ViewMode.NORMAL)
        sub.findItem(SUB_MENU_ITEM_NORMAL).setChecked(true);
    else if (this.currentViewMode == ViewMode.SATELLITE)
        sub.findItem(SUB_MENU_ITEM_SATELLITE).setChecked(true);
    else if (this.currentViewMode == ViewMode.HYBRID)
        sub.findItem(SUB_MENU_ITEM_HYBRID).setChecked(true);

    return super.onCreateOptionsMenu(menu);
}

  @Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId())
    {
        case SUB_MENU_ITEM_NORMAL:
            item.setChecked(!item.isChecked());
            this.currentViewMode = ViewMode.NORMAL;
            Log.i(this.getClass().getName(),  "Normal");
            break;
        case SUB_MENU_ITEM_SATELLITE:
            item.setChecked(!item.isChecked());
            this.currentViewMode = ViewMode.SATELLITE;
            Log.i(this.getClass().getName(),  "Satellite");
            break;
        case SUB_MENU_ITEM_HYBRID:
            item.setChecked(!item.isChecked());
            this.currentViewMode = ViewMode.HYBRID;
            Log.i(this.getClass().getName(), "Hybrid");
            break;
        default:
            super.onOptionsItemSelected(item);
    }
    return true;
}

Answer 1

您应该在onPrepareOptionsMenu（而不是onCreateOptionsMenu）中进行复选框更新，因为它将在每个打开的菜单上调用。创建仅在第一个之前调用。（它不确定这是否会导致您的问题，但是可能，所以值得一试，并且无论如何都会使您的代码更安全）

子菜单设置复选框

1 个答案: