ios - Use UIBarButtonItem icon in UIButton

Question

UIBarButtonItem has multiple icons available. Is it possible to use the icon which appears after setting its identifier to 'trash':

with an UIButton? There is no straighforward method to do that like setting the identifier or style.

Answer 1

New iOS 13 support SF Symbols now
UIImage(systemName: "trash")

---

for swift 4.2 (call it on main thread)

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()

For 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;
}