38

UIBarButtonItem有多个图标可用。是否可以使用将其标识符设置为“垃圾”后出现的图标:

垃圾图标

有一个UIButton?没有像设置标识符样式这样的直接方法。

4

10 回答 10

28

新的iOS 13现在支持SF Symbols
UIImage(systemName: "trash")


对于 swift 4.2 (在主线程上调用它)

extension UIBarButtonItem.SystemItem {
    func image() -> UIImage? {
        let tempItem = UIBarButtonItem(barButtonSystemItem: self,
                                       target: nil,
                                       action: nil)

        // add to toolbar and render it
        let bar = UIToolbar()
        bar.setItems([tempItem],
                     animated: false)
        bar.snapshotView(afterScreenUpdates: true)

        // got image from real uibutton
        let itemView = tempItem.value(forKey: "view") as! UIView
        for view in itemView.subviews {
            if let button = view as? UIButton,
                let image = button.imageView?.image {
                return image.withRenderingMode(.alwaysTemplate)
            }
        }

        return nil
    }
}

UIBarButtonSystemItem.play.image()

对于 Objective-C:

+ (UIImage *)imageFromSystemBarButton:(UIBarButtonSystemItem)systemItem {
    UIBarButtonItem* tempItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:systemItem target:nil action:nil];

    // Add to toolbar and render it
    UIToolbar *bar = [[UIToolbar alloc] init];
    [bar setItems:@[tempItem] animated:NO];
    [bar snapshotViewAfterScreenUpdates:YES];

    // Get image from real UIButton
    UIView *itemView = [(id)tempItem view];
    for (UIView* view in itemView.subviews) {
        if ([view isKindOfClass:[UIButton class]]) {
            return [(UIButton*)view imageForState:UIControlStateNormal];
        }
    }

    return nil;
}
于 2016-03-24T08:55:27.130 回答
16

这是一个适用于任何系统栏按钮项目的解决方案+它支持tintColor

- (void)viewDidLoad {
    [super viewDidLoad];

    [self.button setImage:[self imageFromSystemBarButton:UIBarButtonSystemItemTrash]
                 forState:UIControlStateNormal];

    self.button.tintColor = [UIColor redColor];
}

- (UIImage *)imageFromSystemBarButton:(UIBarButtonSystemItem)systemItem {
    // Holding onto the oldItem (if any) to set it back later
    // could use left or right, doesn't matter
    UIBarButtonItem *oldItem = self.navigationItem.rightBarButtonItem;

    UIBarButtonItem *tempItem = [[UIBarButtonItem alloc]
                                 initWithBarButtonSystemItem:systemItem
                                 target:nil
                                 action:nil];

    // Setting as our right bar button item so we can traverse its subviews
    self.navigationItem.rightBarButtonItem = tempItem;

    // Don't know whether this is considered as PRIVATE API or not
    UIView *itemView = (UIView *)[self.navigationItem.rightBarButtonItem performSelector:@selector(view)];

    UIImage *image = nil;
    // Traversing the subviews to find the ImageView and getting its image
    for (UIView *subView in itemView.subviews) {
        if ([subView isKindOfClass:[UIImageView class]]) {
            image = ((UIImageView *)subView).image;
            break;
        }
    }

    // Setting our oldItem back since we have the image now
    self.navigationItem.rightBarButtonItem = oldItem;

    return image;
}


PS如果您知道更好的方法,请随时改进,谢谢。

于 2014-12-14T18:27:58.757 回答
10

Download the image from somewhere on the web, add it to your project and set the UIButton's image to the image you just downloaded.

I did not find the same as Apple is using but I found this one. Simply change it's color in Pixelmator or Photoshop.

于 2014-01-17T14:14:55.930 回答
10

基于@yycking 的回答,我写了一个合适的Swift 4扩展:

//  UIImage+FromSystemItem.swift

import UIKit

extension UIImage {

    public convenience init?(systemItem sysItem: UIBarButtonItem.SystemItem, renderingMode:UIImage.RenderingMode = .automatic) {
        guard let sysImage = UIImage.imageFromSystemItem(sysItem, renderingMode: renderingMode)?.cgImage else {
            return nil
        }

        self.init(cgImage: sysImage)
    }

    private class func imageFromSystemItem(_ systemItem: UIBarButtonItem.SystemItem, renderingMode:UIImage.RenderingMode = .automatic) -> UIImage? {

        let tempItem = UIBarButtonItem(barButtonSystemItem: systemItem, target: nil, action: nil)

        // add to toolbar and render it
        let bar = UIToolbar()
        bar.setItems([tempItem], animated: false)
        bar.snapshotView(afterScreenUpdates: true)

        // got image from real uibutton
        let itemView = tempItem.value(forKey: "view") as! UIView

        for view in itemView.subviews {
            if view is UIButton {
                let button = view as! UIButton
                let image = button.imageView!.image!
                image.withRenderingMode(renderingMode)
                return image
            }
        }

        return nil
    }
}

带有操作按钮的示例(默认颜色):

let actionImage = UIImage(systemItem: .action)
let myButton = UIButton(frame: CGRect(x: 0, y: 0, width: 30, height: 30))
myButton.setImage(actionImage, for: .normal)

view.addSubview(myButton)

如果您希望无论上下文如何,您的图像始终被视为模板,请将 renderingMode 设置为.alwaysTemplate

 let actionImage = UIImage(systemItem: .action, renderingMode: .alwaysTemplate) 
于 2016-11-12T19:09:01.780 回答
5

正如@Islam Q 答案的评论中已经提到的那样,如果UINavigationItem当前未在屏幕上呈现,则所提供的解决方案可能会失败。例如,如果当前未加载视图控制器,它会失败。事实上,在这些情况下,问题似乎是UINavigationBar缺少布局。

一个更“防弹”的版本是使用专门创建的 UINavigationBar 对象来获取系统项目图像。这也将使保存和恢复任何现有的 UIBarButtonItems 过时。

我已经把它打包成一个小助手类:

LEABarButtonSystemItemImage.h:

#import <UIKit/UIKit.h>


/**
 LEABarButtonSystemItemImage interface

 */
@interface LEABarButtonSystemItemImage : NSObject

+ (UIImage *)imageFromBarButtonSystemItem:(UIBarButtonSystemItem)pBarButtonSystemItem;
+ (UIImage *)customImageForBarButtonSystemItem:(UIBarButtonSystemItem)pBarButtonSystemItem;

+ (NSDictionary<__kindof NSNumber*, __kindof UIImage*> *)barButtonItemImages;

@end

LEABarButtonSystemItemImage.m

#import "LEABarButtonSystemItemImage.h"


/**
 LEABarButtonSystemItemImage implementation

 */
@implementation LEABarButtonSystemItemImage

/*
 imageFromBarButtonSystemItem:

 */
+ (UIImage *)imageFromBarButtonSystemItem:(UIBarButtonSystemItem)pBarButtonSystemItem {

    static const CGFloat    defaultNBBtnHW  = 44.0;

    UINavigationBar *   tempNavigationBar = [[UINavigationBar alloc] initWithFrame:CGRectMake(0, 0, defaultNBBtnHW, defaultNBBtnHW)];
    UINavigationItem *  tempNavigationItem = [[UINavigationItem alloc] init];
    UIBarButtonItem *   tempBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:pBarButtonSystemItem target:nil action:NULL];

    tempNavigationBar.items = @[tempNavigationItem];
    tempNavigationItem.rightBarButtonItems = @[tempBarButtonItem];

    UIImage *           barButtonSystemItemImage = nil;
    @try {
        UIView *        barButtonItemView = [tempBarButtonItem valueForKey:@"view"];
        for (UIView* subview in barButtonItemView.subviews) {
            if ([subview isKindOfClass:UIImageView.class]) {
                barButtonSystemItemImage = ((UIImageView *)subview).image;
                break;
            }
        }
    } @catch (...) { NSLog(@"%s: Exception while retrieving image from UIBarButtonItem!", __PRETTY_FUNCTION__); }

    return (barButtonSystemItemImage ?: [LEABarButtonSystemItemImage customImageForBarButtonSystemItem:pBarButtonSystemItem]);
}

/*
 customImageForBarButtonSystemItem:

 */
+ (UIImage *)customImageForBarButtonSystemItem:(UIBarButtonSystemItem)pBarButtonSystemItem {

    NSString *  customBarButtonSystemItemImageName = nil;
    switch (pBarButtonSystemItem) {
        case UIBarButtonSystemItemDone:             customBarButtonSystemItemImageName = @"customBarButtonSystemItemDone";          break;
        case UIBarButtonSystemItemCancel:           customBarButtonSystemItemImageName = @"customBarButtonSystemItemCancel";        break;
        case UIBarButtonSystemItemEdit:             customBarButtonSystemItemImageName = @"customBarButtonSystemItemEdit";          break;
        case UIBarButtonSystemItemSave:             customBarButtonSystemItemImageName = @"customBarButtonSystemItemSave";          break;
        case UIBarButtonSystemItemAdd:              customBarButtonSystemItemImageName = @"customBarButtonSystemItemAdd";           break;
        case UIBarButtonSystemItemCompose:          customBarButtonSystemItemImageName = @"customBarButtonSystemItemCompose";       break;
        case UIBarButtonSystemItemReply:            customBarButtonSystemItemImageName = @"customBarButtonSystemItemReply";         break;
        case UIBarButtonSystemItemAction:           customBarButtonSystemItemImageName = @"customBarButtonSystemItemAction";        break;
        case UIBarButtonSystemItemOrganize:         customBarButtonSystemItemImageName = @"customBarButtonSystemItemOrganize";      break;
        case UIBarButtonSystemItemBookmarks:        customBarButtonSystemItemImageName = @"customBarButtonSystemItemBookmarks";     break;
        case UIBarButtonSystemItemSearch:           customBarButtonSystemItemImageName = @"customBarButtonSystemItemSearch";        break;
        case UIBarButtonSystemItemRefresh:          customBarButtonSystemItemImageName = @"customBarButtonSystemItemRefresh";       break;
        case UIBarButtonSystemItemStop:             customBarButtonSystemItemImageName = @"customBarButtonSystemItemStop";          break;
        case UIBarButtonSystemItemCamera:           customBarButtonSystemItemImageName = @"customBarButtonSystemItemCamera";        break;
        case UIBarButtonSystemItemTrash:            customBarButtonSystemItemImageName = @"customBarButtonSystemItemTrash";         break;
        case UIBarButtonSystemItemPlay:             customBarButtonSystemItemImageName = @"customBarButtonSystemItemPlay";          break;
        case UIBarButtonSystemItemPause:            customBarButtonSystemItemImageName = @"customBarButtonSystemItemPause";         break;
        case UIBarButtonSystemItemRewind:           customBarButtonSystemItemImageName = @"customBarButtonSystemItemRewind";        break;
        case UIBarButtonSystemItemFastForward:      customBarButtonSystemItemImageName = @"customBarButtonSystemItemFastForward";   break;
        case UIBarButtonSystemItemUndo:             customBarButtonSystemItemImageName = @"customBarButtonSystemItemUndo";          break;
        case UIBarButtonSystemItemRedo:             customBarButtonSystemItemImageName = @"customBarButtonSystemItemRedo";          break;
        case UIBarButtonSystemItemPageCurl:         customBarButtonSystemItemImageName = @"customBarButtonSystemItemPageCurl";      break;
        default:    break;
    }

    return (customBarButtonSystemItemImageName
            ? [UIImage imageNamed:customBarButtonSystemItemImageName]
            : nil);
}

/*
 barButtonItemImages

 */
+ (NSDictionary<__kindof NSNumber*, __kindof UIImage*> *)barButtonItemImages {

    NSMutableDictionary<__kindof NSNumber*, __kindof UIImage*> *    barButtonItemImages = [NSMutableDictionary dictionary];
    // From:    https://github.com/nst/iOS-Runtime-Headers/blob/master/Frameworks/UIKit.framework/UIBarButtonItem.h
    //          unsigned int systemItem : 7;
    for (NSUInteger uIndex = 0; uIndex < (1<<7); ++uIndex) {
        UIImage*    systemImage = [LEABarButtonSystemItemImage imageFromBarButtonSystemItem:uIndex];
        if (systemImage) {
            [barButtonItemImages setObject:systemImage forKey:@(uIndex)];
        }
    }
    NSLog(@"%s: %@", __PRETTY_FUNCTION__, barButtonItemImages);
    return barButtonItemImages;
}

@end

作为 add on/fallback ,如果无法检索到系统项目图像,该方法将返回自定义图像。当然,这些自定义图像必须存在于应用程序包中。

最后一个方法“barButtonImages”是为了好奇而实现的……在 UIBarButtonItem 标头中,成员 systemItem 被声明为使用 7 位(0..127)。目前,从 UIBarButtonSystemItemDone 到 UIBarButtonItemSystemItemPageCurl 仅记录了 22 个值......事实上;我发现了一些索引超过 100 的未记录图像(在 6S+ 模拟器中的 iOS 9.3 上测试):-)

于 2016-04-11T18:22:29.003 回答
4

所有 iOS 系统图标都可以使用一个方便的小应用程序(非常合适)iOS Artwork Extractor 来提取。当我想模仿 iOS 系统行为时,我一直使用它。

在以下位置下载 Xcode 项目:

https://github.com/0xced/iOS-Artwork-Extractor

于 2014-10-08T05:02:12.830 回答
2

在 Swift 4.2 中使用 Quartz2D

基于扩展提取图像的解决方案UIBarButtonSystemItem在 iOS 11/12 中不起作用,因此我决定添加一个自定义类来绘制图标而不添加任何 .png

在此处输入图像描述

这是为 .trash 和 .action 实现的,它们是我项目中需要的图标。随意添加其余部分。

使用方法如下(需要符合SystemIConDelegate协议,设置Delegate属性并添加需要的方法):

let trashIcon = SystemIcon(withType: .trash)
trashIcon.delegate = self
shareButton = UIButton()
shareButton.addSubview(trashIcon)

课堂在SystemIcon这里。它针对 30 X 30 点进行了优化:

import UIKit
protocol SystemIconDelegate {
    func systemIconButtonClicked()
}
class SystemIcon: UIView {
    var type: UIBarButtonItem.SystemItem!
    let color = UIColor.blue
    var delegate: SystemIconDelegate?   
    convenience init(withType: UIBarButtonItem.SystemItem) {
        self.init(frame: CGRect(x: 0, y: 0, width: 30, height: 30))
        self.backgroundColor = .clear
        self.type = withType
    }
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        self.delegate?.systemIconButtonClicked()
    }
    override func draw(_ rect: CGRect) {
        let w = self.frame.width
        let h = self.frame.height
        let context = UIGraphicsGetCurrentContext()
        context?.setStrokeColor(color.cgColor)
        context?.setLineWidth(1.0)
        switch type! {
        case .action:
            //Box
            context?.stroke(CGRect(x: w * 0.16, y: h * 0.3, width: w * 0.69, height: h * 0.69))
            context?.setFillColor(UIColor.white.cgColor)
            context?.fill(CGRect(x: w * 0.4, y: 0, width: w * 0.2, height: h * 0.5))
            //Arrow
            context?.move(to: CGPoint(x: w * 0.5, y: h * 0.02))
            context?.addLine(to: CGPoint(x: w * 0.5, y: h * 0.64))
            context?.move(to: CGPoint(x: w * 0.33, y: h * 0.19))
            context?.addLine(to: CGPoint(x: w * 0.5, y: h * 0.02))
            context?.addLine(to: CGPoint(x: w * 0.67, y: h * 0.19))
            context?.strokePath()
        case .trash:
            context?.move(to: CGPoint(x: w * 0.1, y: h * 0.15))
            context?.addLine(to: CGPoint(x: w * 0.9, y: h * 0.15))
            //Can
            context?.move(to: CGPoint(x: w * 0.2, y: h * 0.15))
            context?.addArc(tangent1End: CGPoint(x: w * 0.25, y: h * 0.95), tangent2End: CGPoint(x: w * 0.5, y:h * 0.95), radius: CGFloat.x(2.0))
            context?.addArc(tangent1End: CGPoint(x: w * 0.75, y: h * 0.95), tangent2End: CGPoint(x: w * 0.8, y: h * 0.15), radius: CGFloat.x(2.0))
            context?.addLine(to: CGPoint(x: w * 0.8, y: h * 0.15))
            // Handle
            context?.move(to: CGPoint(x: w * 0.34, y: h * 0.15))
            context?.addArc(tangent1End: CGPoint(x: w * 0.34, y: h * 0.02), tangent2End: CGPoint(x: w * 0.5, y: h * 0.02), radius: CGFloat.x(2.0))
            context?.addArc(tangent1End: CGPoint(x: w * 0.66, y : h * 0.02), tangent2End: CGPoint(x: w * 0.66, y: h * 0.15), radius: CGFloat.x(2.0))
            context?.addLine(to: CGPoint(x: w * 0.66, y: h * 0.15))
            //Lines
            context?.move(to: CGPoint(x: w * 0.35, y: h * 0.25))
            context?.addLine(to: CGPoint(x: w * 0.38, y: h * 0.8))
            context?.move(to: CGPoint(x: w * 0.5, y: h * 0.25))
            context?.addLine(to: CGPoint(x: w * 0.5, y: h * 0.8))
            context?.move(to: CGPoint(x: w * 0.65, y: h * 0.25))
            context?.addLine(to: CGPoint(x: w * 0.62, y: h*0.8))
        default:
            break
        }
        context?.strokePath()
    }
}
于 2018-10-04T18:58:32.393 回答
1

我将它用于表格单元格中的 imageView 并且不知何故,无论我在哪里设置它,色调颜色都不起作用......所以我最终得到了这段代码,您可以在其中为图像设置颜色。

+ (UIImage *)imageFromSystemBarButton:(UIBarButtonSystemItem)systemItem :(UIColor *) color {
    UIToolbar *bar = UIToolbar.new;
    UIBarButtonItem *buttonItem = [UIBarButtonItem createWithItem:systemItem];
    [bar setItems:@[buttonItem] animated:NO];
    [bar snapshotViewAfterScreenUpdates:YES];
    for (UIView *view in [(id) buttonItem view].subviews)
        if ([view isKindOfClass:UIButton.class]) {
            UIImage *image = [((UIButton *) view).imageView.image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
            UIGraphicsBeginImageContextWithOptions(image.size, NO, image.scale);
            [color set];
            [image drawInRect:CGRectMake(0, 0, image.size.width, image.size.height)];
            image = UIGraphicsGetImageFromCurrentImageContext();
            UIGraphicsEndImageContext();
            return image;
    }
    return nil;
}
于 2018-04-13T17:41:36.213 回答
1

基于@yycking答案,这里是 Xamarin.iOS C# 端口:

[DllImport (Constants.ObjectiveCLibrary, EntryPoint = "objc_msgSend")]
static extern IntPtr IntPtr_objc_msgSend (IntPtr receiver, IntPtr selector);

public static UIImage GetImage (UIBarButtonSystemItem systemItem)
{
    var tempItem = new UIBarButtonItem (systemItem);

    // Add to toolbar and render it
    var bar = new UIToolbar ();
    bar.SetItems (new [] { tempItem }, false);
    bar.SnapshotView (true);

    // Get image from real UIButton
    var selHandle = Selector.GetHandle ("view");
    var itemView = Runtime.GetNSObject<UIView> (IntPtr_objc_msgSend (tempItem.Handle, selHandle));
    foreach (var view in itemView?.Subviews) {
        if (view is UIButton button)
            return button.ImageForState (UIControlState.Normal);
    }

    return null;
}
于 2019-02-24T16:25:50.513 回答
0

斯威夫特 5

让删除= UIBarButtonItem(barButtonSystemItem:.trash,目标:自我,动作:#selector(deleteSelected))

于 2021-04-26T05:37:09.347 回答