NSViewController viewWillAppear可可

Question

我想在可可MAC应用程序开发中交换视图，比如UINavigationController在可可触摸中的推送/弹出视图。这是一个推送和流行视图的应用程序的要求，不知何故我可以做到这一点，但现在我在项目的中间，我想在可可的viewWillAppear的东西。

Answer 1

仅供参考，iOS视图生命周期方法(viewDidLoad、viewWillAppear、viewDidAppear等)从OSX10.10Yosemite(或更高版本)开始可用。

注意事项:如果您计划让应用程序在10.10 OSX之前的版本上运行，请不要实现此类方法，因为它们不会被较早的版本识别(因此不会执行其中的代码)

Answer 2

这样的方法在Mac上不可用。与iOS UI相比，OSX有很大的不同。使用-(空)loadView进行初始UI更新(或-(空)awakeFromNib，如果您的UI是在接口生成器中设计并从xib文件加载的)，然后在此之后以编程方式发出特定的、按需的UI更新请求，无论何时您调用showWindow、makeKeyAndOrderFront、获取通知、从委托获取回调等。

Answer 3

我想出了一些这样的东西：

标题：

@protocol GWViewExtensions <NSObject>
- (void) viewWasAddedToSuperview;
@end

@interface GWView : NSView

//set to the view controller managing this view to get NSResponder udpates,
//and GWViewExtension protocol method calls.
@property (weak,nonatomic) IBOutlet NSViewController * viewController;

@end

实施：

#import "GWView.h"

@implementation GWView

- (void) awakeFromNib {
    [self setNeedsDisplay:TRUE];
}

- (void) addSubview:(NSView *)aView {
    [super addSubview:aView];
    if([aView isMemberOfClass:[GWView class]]) {
        GWView * gview = (GWView *)aView;
        if(gview.viewController && [gview.viewController conformsToProtocol:@protocol(GWViewExtensions)]) {
            if([gview.viewController respondsToSelector:@selector(viewWasAddedToSuperview)]) {
                [gview.viewController performSelectorOnMainThread:@selector(viewWasAddedToSuperview) withObject:nil waitUntilDone:FALSE];
            }
        }
    }
}

- (void) setViewController:(NSViewController *) newController {
    if(_viewController) {
        NSResponder *controllerNextResponder = [_viewController nextResponder];
        [super setNextResponder:controllerNextResponder];
        [_viewController setNextResponder:nil];
    }
    _viewController = newController;
    if(newController) {
        NSResponder *ownNextResponder = [self nextResponder];
        [super setNextResponder:_viewController];
        [_viewController setNextResponder:ownNextResponder];
    }
}

- (void)setNextResponder:(NSResponder *)newNextResponder {
    if(self.viewController) {
        [self.viewController setNextResponder:newNextResponder];
        return;
    }
    [super setNextResponder:newNextResponder];
}

- (void) setBackgroundColor:(NSColor *)backgroundColor {
    _backgroundColor = backgroundColor;
    [self setNeedsDisplay:TRUE];
}

- (void) drawRect:(NSRect) dirtyRect {
    [super drawRect:dirtyRect];
    if(self.backgroundColor) {
        NSGraphicsContext * theContext = [NSGraphicsContext currentContext];
        [theContext saveGraphicsState];
        [[NSGraphicsContext currentContext] setPatternPhase:NSMakePoint(0,[self frame].size.height)];
        [self.backgroundColor set];
        NSRectFill([self bounds]);
        [theContext restoreGraphicsState];
    }
}

- (void) dealloc {
    self.backgroundColor = nil;
}

@end

使用：

#import <Cocoa/Cocoa.h>
#import "GWView.h"

@interface GWDribbbleShotDetailColumn : NSViewController <GWViewExtensions>
@end


#import "GWDribbbleShotDetailColumn.h"

@interface GWDribbbleShotDetailColumn ()
@end

@implementation GWDribbbleShotDetailColumn

- (void) viewWasAddedToSuperview {
    NSRect svb = self.view.superview.bounds;
    NSRect sf = self.view.frame;
    sf.size.height = NSHeight(svb);
    sf.size.width = NSWidth(svb);
    self.view.frame = sf;
}

@end