Custom Control equivalent in XCode/MonoMac

问题:

I'm a .NET developer trying his hand at an OSX port of a Windows application. I'm using MonoDevelop and MonoMac (with the XCode Interface Builder) to create my UI.

Coming from Windows, I'm trying to understand the Cocoa equivalent of a "UserControl" since I used these extensively in my WinForm version. I have a group of controls (let's say a label, textbox and button) that I want to package up and reuse in various places throughout my Cocoa UI.

From what I understand, I need to create a "custom view" by subclassing NSView (let's call it "MyView"). I can create "MyView" in the Interface Builder alright, but when I use it on my main window it always appears empty/blank.

Here's how I'm placing the control on my main form in IB: I add a Custom View (NSView) from the object library, then change the "class" property under "Custom Class" to "MyView". It's not a problem if the control doesn't render at design time, but it's totally empty at runtime too.

I suspect I'm missing something really simple/obvious. Are custom views supposed to be used this way? All the examples I've found online seem to discuss custom drawing, which I don't want (I just want to use a bunch of controls together so I can reuse them). Can anyone out there shed some light on this for me?

Thanks in advance.

回答1:

If you just want a group of standard controls, then you may want a standalone view NIB/XIB. Then you'd load that NIB each time you want to instantiate that group, get the top-level view from it, and insert that view into some other view hierarchy. You'd use an NSViewController (or a custom subclass) to own and load that NIB.

You can also add a free-standing view to a NIB that already contains, say, a window. The NIB's owner (often an instance of NSWindowController or a subclass) would have an outlet to refer to that free-standing view hierarchy. Your code could then use that view hierarchy at will, inserting it into the window's view hierarchy at an appropriate place.

You don't typically use a custom view class just to group standard controls. You only make a view subclass to make a non-standard view, one that draws in a custom manner or provides a different manipulation technique.

回答2:

This worked for me:

1. Drop a "Custom View" onto your window (do NOT rename the Class in identity inspector).

2. Make an outlet for the Custom View in your window's controller called 'CustomView'.

3. In your window controllers awakeFromNib method add the following code

    this.CustomView.AddSubview(new YourCustomViewController().View);

Note: other answers to this question assume your view has no XIB, and thus shows empty because it is not loaded properly.