如何在MonoTouch中为继承的视图创建UIAppearance代理? [英] How to create a UIAppearance proxy for an inherited view in MonoTouch?
问题描述
我创建了一个 UIButton
的子类,它充当 UIBarButtonItem
中的自定义后退按钮:
I created a subclass of UIButton
which acts as a custom Back button inside UIBarButtonItem
:
- - - - - - - - - - - - - - - - -
| UIBarButtonItem |
| ------------------------ |
/ |
| \ BackButton : UIButton | |
------------------------
| _ _ _ _ _ _ _ _ _ _ _|
当我将代码切换为使用 UIAppearance
,我注意到 BackButton.Appearance
是毫无疑问的,继承自 UIButton.Appearance
,因此更改它将会改变整个应用程序中的所有 UIButton
,而不仅仅是我的自定义按钮。
As I was switching my code to using UIAppearance
, I noticed that BackButton.Appearance
is, unsuprisingly, inherited from UIButton.Appearance
, and therefore changing it will change all UIButton
s throughout the application and not just my custom buttons.
我知道我可以使用 AppearanceWhenContainedIn
但是,因为 UIBarButtonItem
不是外观容器,我必须在它们之间插入另一个视图以识别后退按钮,我我不想这样做。
I know I can use AppearanceWhenContainedIn
but, because UIBarButtonItem
is not an appearance container, I'd have to insert another view between them to recognize back buttons, which I don't want to do.
如何为我的自定义 UIAppearance
代理> UIButton 具有 UIButton.UIButtonAppearance
中所有可用方法的子类?我注意到它的构造函数是内部的。
How do I provide a UIAppearance
proxy for my custom UIButton
subclass that has all the methods available in UIButton.UIButtonAppearance
? I noticed that its constructor is internal.
推荐答案
虽然可能有一个更简单的答案,但我最终继承了 UIAppearance
直接复制粘贴相关的 UIButton
和 UIButton + UIButtonAppearance
绑定从MonoDevelop C#反汇编程序实现并在此处修复内部字段。
Although there may be a simpler answer, I ended up inheriting from UIAppearance
directly and copy-pasting relevant piece of UIButton
and UIButton+UIButtonAppearance
binding implementation from MonoDevelop C# disassembler and fixing internal fields here and there.
内部 BackButton
:
static readonly IntPtr class_ptr = Class.GetHandle(typeof(BackButton));
public new static BackButtonAppearance Appearance
{
get {
return new BackButtonAppearance (Messaging.IntPtr_objc_msgSend (class_ptr, UIAppearance.SelectorAppearance));
}
}
public new static BackButtonAppearance AppearanceWhenContainedIn (params Type[] containers)
{
return new BackButtonAppearance (UIAppearance.GetAppearance (class_ptr, containers));
}
嵌套 BackButtonAppearance
:
public class BackButtonAppearance : UIAppearance {
public BackButtonAppearance(IntPtr handle) : base(handle) { }
// These are copied from UIButton disassembly:
static readonly IntPtr selSetBackgroundImageForState_ = Selector.GetHandle ("setBackgroundImage:forState:");
static readonly IntPtr selSetTitleShadowColorForState_ = Selector.GetHandle ("setTitleShadowColor:forState:");
static readonly IntPtr selSetTitleColorForState_ = Selector.GetHandle ("setTitleColor:forState:");
// These are copied from UIButton+UIButtonAppearance disassembly,
// with internal UIButton.selSet* fields replaced by fields declared above.
[Export ("setBackgroundImage:forState:"), CompilerGenerated]
public virtual void SetBackgroundImage (UIImage image, UIControlState forState)
{
UIApplication.EnsureUIThread ();
if (this.IsDirectBinding) {
Messaging.void_objc_msgSend_IntPtr_UInt32 (base.Handle, selSetBackgroundImageForState_, (image != null) ? image.Handle : IntPtr.Zero, (uint)forState);
} else {
Messaging.void_objc_msgSendSuper_IntPtr_UInt32 (base.SuperHandle, selSetBackgroundImageForState_, (image != null) ? image.Handle : IntPtr.Zero, (uint)forState);
}
}
[Export ("setTitleColor:forState:"), CompilerGenerated]
public virtual void SetTitleColor (UIColor color, UIControlState forState)
{
UIApplication.EnsureUIThread ();
if (this.IsDirectBinding) {
Messaging.void_objc_msgSend_IntPtr_UInt32 (base.Handle, selSetTitleColorForState_, (color != null) ? color.Handle : IntPtr.Zero, (uint)forState);
} else {
Messaging.void_objc_msgSendSuper_IntPtr_UInt32 (base.SuperHandle, selSetTitleColorForState_, (color != null) ? color.Handle : IntPtr.Zero, (uint)forState);
}
}
[Export ("setTitleShadowColor:forState:"), CompilerGenerated]
public virtual void SetTitleShadowColor (UIColor color, UIControlState forState)
{
UIApplication.EnsureUIThread ();
if (this.IsDirectBinding) {
Messaging.void_objc_msgSend_IntPtr_UInt32 (base.Handle, selSetTitleShadowColorForState_, (color != null) ? color.Handle : IntPtr.Zero, (uint)forState);
} else {
Messaging.void_objc_msgSendSuper_IntPtr_UInt32 (base.SuperHandle, selSetTitleShadowColorForState_, (color != null) ? color.Handle : IntPtr.Zero, (uint)forState);
}
}
}
这可以让我携带自定义视图以支持UIAppearance风格的API。
This allows me to bring my custom view to support UIAppearance-style API.
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