И, основываясь на ответе Эмиля (и Слагстера), я обнаружил, что немного проще расширить TabControl (вместо TabPages). Таким образом, я могу установить страницы невидимыми или видимыми одним вызовом, а также не беспокоиться о нулевых родительских ссылках для невидимых страниц.
Пример вызова:
MyTabControl.SetTabVisibilityExt ("tabTests", isDeveloper);
public static class WinFormExtensions
{
public static TabPage FindTabByNameExt( this TabControl tc, string tabName)
{
foreach (TabPage tab in tc.TabPages)
if (tab.Name == tabName)
return tab;
return null;
}
private struct TabPageData
{
internal int Index;
internal TabControl Parent;
internal TabPage Page;
internal TabPageData(int index, TabControl parent, TabPage page)
{
Index = index;
Parent = parent;
Page = page;
}
internal static string GetKey(TabControl tc, TabPage tabPage)
{
string key = "";
if (tc == null || tabPage == null)
return key;
key = $"{tc.Name}:{tabPage.Name}";
return key;
}
internal static string GetKey(TabControl tc, string tabName)
{
string key = "";
if (tc == null)
return key;
key = $"{tc.Name}:{tabName}";
return key;
}
}
private static Dictionary<string, TabPageData> hiddenPages = new Dictionary<string, TabPageData>();
public static void SetTabVisibleExt(this TabControl tc, string tabName)
{
if (tc == null || tc.IsDisposed)
return;
if (tc.IsTabVisibleExt(tabName))
return;
string key = TabPageData.GetKey(tc, tabName);
if (hiddenPages.ContainsKey(key))
{
TabPageData tpinfo = hiddenPages[key];
if (tpinfo.Index < tc.TabPages.Count)
tc.TabPages.Insert(tpinfo.Index, tpinfo.Page); // add the page in the same position it had
else
tc.TabPages.Add(tpinfo.Page);
hiddenPages.Remove(key);
return;
}
else
throw new ApplicationException($"TabControl={tc.Name} does not have Invisible TabPage={tabName}");
}
public static void SetTabInvisibleExt(this TabControl tc, string tabName)
{
if (tc == null || tc.IsDisposed)
return;
if (IsTabInvisibleExt(tc, tabName))
return;
TabPage page = tc.FindTabByNameExt(tabName);
if (page != null)
{
string key = TabPageData.GetKey(tc, page);
TabPageData tpInfo = new TabPageData(tc.TabPages.IndexOf(page), tc, page);
tc.TabPages.Remove(page);
hiddenPages.Add(key, tpInfo);
return;
}
else // Could not find the tab, and it isn't already invisible.
throw new ApplicationException($"TabControl={tc.Name} could not locate TabPage={tabName}");
}
// A convenience method to combine the SetTabInvisible and SetTabInvisible.
public static void SetTabVisibilityExt(this TabControl tc, string tabName, bool? isVisible)
{
if (isVisible == null)
return;
if (isVisible.Value)
tc.SetTabVisibleExt(tabName);
else
tc.SetTabInvisibleExt(tabName);
}
public static bool IsTabVisibleExt(this TabControl tc, string tabName)
{
TabPage page = tc.FindTabByNameExt(tabName);
return page != null;
}
public static bool IsTabInvisibleExt(this TabControl tc, string tabName)
{
string key = TabPageData.GetKey(tc, tabName);
return hiddenPages.ContainsKey(key);
}
public static void CleanUpHiddenPagesExt(this TabControl tc)
{
foreach (TabPageData info in hiddenPages.Values)
{
if (info.Parent != null && info.Parent.Equals((TabControl)tc))
info.Page.Dispose();
}
}
}