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：
有一个UIButton？没有像设置标识符或样式这样的直接方法。
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36190 次
10 回答
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：
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
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