如何从头开始以编程方式创建NSCollectionView？

Question

NSCollectionView仍然是我见过的Cocoa API中最神秘的部分之一.文档很差,并且有许多移动部件,其中许多通常在Interface Builder中实现,使文档具有挑战性.

请提供示例代码以创建最简单的情况,NSCollectionView其中显示文本字段或按钮而不使用Xcode,其中每个文本字段或按钮具有不同的标题.假设一个新的Xcode项目使用默认的windowIBOutlet.

对于此示例,在数据源更改时不需要绑定来更新NSCollectionView.只需显示原型对象的网格,并将每个对象的标题设置为某个值.

如果我们能够为很多人提供一个如何做到这一点的好例子,我认为这将有助于所有与之合作NSCollectionViews并且和我一样困惑的人.

请求摘要

• 提供示例代码以在新的Xcode项目中呈现NSCollectionView
• 不要使用Interface Builder,请使用提供的IBOutlet默认窗口
• NSCollectionView应包含文本字段或按钮,您的选择
• 视图中的每个项目都应具有不同的标题
• 不需要绑定

如果有符合这些要求的示例代码,请提供一个很棒的链接!

Answer 1

我不确定在以编程方式创建集合视图并且没有绑定方面有很多见解,但是在这里.

介绍

使用集合视图时基本上有四个组件:

• View:NSView负责显示信息的子类;
• 集合视图本身;
• 视图控制器:NSCollectionViewItem用作集合视图项原型的子类;
• 模型:一个对象数组.

通常,视图是在Interface Builder中设计的,模型是由Cocoa绑定调解的.

以编程方式执行:

常量

static const NSSize buttonSize = {80, 20};
static const NSSize itemSize = {100, 40};
static const NSPoint buttonOrigin = {10, 10};

视图

这是一个包含按钮的标准视图(Interface Builder中的自定义视图).请注意,视图具有固定大小.

@interface BVView : NSView
@property (weak) NSButton *button;
@end

@implementation BVView
@synthesize button;
- (id)initWithFrame:(NSRect)frameRect {
    self = [super initWithFrame:(NSRect){frameRect.origin, itemSize}];
    if (self) {
        NSButton *newButton = [[NSButton alloc] 
            initWithFrame:(NSRect){buttonOrigin, buttonSize}];
        [self addSubview:newButton];
        self.button = newButton;
    }
    return self;
}
@end

查看控制器(原型)

通常,视图控制器从nib文件加载其视图.在视图控制器未从nib文件获取其视图的极少数情况下,开发人员必须在视图控制器接收-setView:之前发送它-view,或者覆盖-loadView.以下代码执行后者.

视图控制器通过接收相应的模型对象-setRepresentedObject:.我已经覆盖了它,以便在模型对象发生变化时更新按钮标题.请注意,这可以通过使用Cocoa绑定来完成,而不需要任何代码.

请注意,此代码都不是特定于集合视图的 - 它是一般视图控制器行为.

@interface BVPrototype : NSCollectionViewItem
@end

@implementation BVPrototype
- (void)loadView {
    [self setView:[[BVView alloc] initWithFrame:NSZeroRect]];
}
- (void)setRepresentedObject:(id)representedObject {
    [super setRepresentedObject:representedObject];
    [[(BVView *)[self view] button] setTitle:representedObject];
}
@end

模型

表示按钮标题的简单字符串数组:

@property (strong) NSArray *titles;
self.titles = [NSArray arrayWithObjects:@"Case", @"Molly", @"Armitage",
    @"Hideo", @"The Finn", @"Maelcum", @"Wintermute", @"Neuromancer", nil];

集合视图

到目前为止,唯一建立的关系是BVView项目prototype(BVPrototype)使用的view ().必须告知集合视图应该使用的原型以及从中获取数据的模型.

NSCollectionView *cv = [[NSCollectionView alloc]
    initWithFrame:[[[self window] contentView] frame]]; 
[cv setItemPrototype:[BVPrototype new]];
[cv setContent:[self titles]];

应用程序代表的完整源代码

#import "BVAppDelegate.h"


static const NSSize buttonSize = { 80, 20 };
static const NSSize itemSize = { 100, 40 };
static const NSPoint buttonOrigin = { 10, 10 };


@interface BVView : NSView
@property (weak) NSButton *button;
@end

@implementation BVView
@synthesize button;
- (id)initWithFrame:(NSRect)frameRect {
    self = [super initWithFrame:(NSRect){frameRect.origin, itemSize}];
    if (self) {
        NSButton *newButton = [[NSButton alloc]
            initWithFrame:(NSRect){buttonOrigin, buttonSize}];
        [self addSubview:newButton];
        self.button = newButton;
    }
    return self;
}
@end


@interface BVPrototype : NSCollectionViewItem
@end

@implementation BVPrototype
- (void)loadView {
    [self setView:[[BVView alloc] initWithFrame:NSZeroRect]];
}
- (void)setRepresentedObject:(id)representedObject {
    [super setRepresentedObject:representedObject];
    [[(BVView *)[self view] button] setTitle:representedObject];
}
@end


@interface BVAppDelegate ()
@property (strong) NSArray *titles;
@end

@implementation BVAppDelegate

@synthesize window = _window;
@synthesize titles;

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
    self.titles = [NSArray arrayWithObjects:@"Case", @"Molly", @"Armitage",
        @"Hideo", @"The Finn", @"Maelcum", @"Wintermute", @"Neuromancer", nil];

    NSCollectionView *cv = [[NSCollectionView alloc]
        initWithFrame:[[[self window] contentView] frame]]; 
    [cv setItemPrototype:[BVPrototype new]];
    [cv setContent:[self titles]];

    [cv setAutoresizingMask:(NSViewMinXMargin
                             | NSViewWidthSizable
                             | NSViewMaxXMargin
                             | NSViewMinYMargin
                             | NSViewHeightSizable
                             | NSViewMaxYMargin)];
    [[[self window] contentView] addSubview:cv];
}

@end

Answer 2

@Bavarious你在那里做得很好.这只是一个很棒的教程,我有时会错过Apple Docs.

我在Swift(v2)中为任何感兴趣的人重写了Bavarious的代码:

// AppDelegate.swift:

import Cocoa

let buttonSize:NSSize = NSSize(width: 80, height: 20)
let itemSize:NSSize = NSSize(width: 100, height: 40)
let buttonOrigin:NSPoint = NSPoint(x: 10, y: 10)

let titles:[String] = ["Case", "Molly", "Armitage", "Hideo", "The Finn", "Maelcum", "Wintermute", "Neuromancer"]

@NSApplicationMain
class AppDelegate: NSObject, NSApplicationDelegate {

    @IBOutlet weak var window: NSWindow!

    func applicationDidFinishLaunching(aNotification: NSNotification) {
        let cv = NSCollectionView(frame: self.window.contentView!.frame)
        cv.itemPrototype = BVTemplate()
        cv.content = titles

        cv.autoresizingMask = NSAutoresizingMaskOptions.ViewMinXMargin
            .union(NSAutoresizingMaskOptions.ViewWidthSizable)
            .union(NSAutoresizingMaskOptions.ViewMaxXMargin)
            .union(NSAutoresizingMaskOptions.ViewMinYMargin)
            .union(NSAutoresizingMaskOptions.ViewMaxYMargin)
            .union(NSAutoresizingMaskOptions.ViewHeightSizable)

        window.contentView!.addSubview(cv)
    }

    func applicationWillTerminate(aNotification: NSNotification) {
        // Insert code here to tear down your application
    }
}

// BVTemplate.swift:

import Cocoa

class BVTemplate: NSCollectionViewItem {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do view setup here.
    }

    override func loadView() {
        print("loadingView")
        self.view = BVView(frame: NSZeroRect)
    }

    override var representedObject:AnyObject? {
        didSet {
            if let representedString = representedObject as? String {
                (self.view as! BVView).button?.title = representedString
            }
        }
    }
}

// BVView.swift:

import Cocoa

class BVView: NSView {

    var button:NSButton?

    override init(frame frameRect: NSRect) {
        super.init(frame: NSRect(origin: frameRect.origin, size: itemSize))
        let newButton:NSButton = NSButton(frame: NSRect(origin: buttonOrigin, size: buttonSize))
        self.addSubview(newButton)
        self.button = newButton
    }

    required init?(coder: NSCoder) {
        super.init(coder: coder)
    }
}