为 UITableView 滑动操作设置自定义字体 (UIContextualAction)

Question

How do you set a custom font for the title in UIContextualAction ?

I have tried UIAppearance but without any luck...

Cheers! :)

Answer 1

I have found a way to do this by using the image property instead of the title...

Standard font (Remove/Rename)

Custom font (Remove/Rename)

To create an image of a label I have this extension:

extension UIImage {

    /// This method creates an image of a view
    convenience init?(view: UIView) {

        // Based on https://stackoverflow.com/a/41288197/1118398
        let renderer = UIGraphicsImageRenderer(bounds: view.bounds)
        let image = renderer.image { rendererContext in
            view.layer.render(in: rendererContext.cgContext)
        }

        if let cgImage = image.cgImage {
            self.init(cgImage: cgImage, scale: UIScreen.main.scale, orientation: .up)
        } else {
            return nil
        }
    }
}

And then I simply have:

override func tableView(_ tableView: UITableView, trailingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {

    let action = UIContextualAction(style: .destructive, title: nil) { action, view, completion in
        // Your swipe action code!
    }
    let label = UILabel()
    label.text = // Your swipe action text!
    label.font = // Your custom font!
    label.sizeToFit()
    action.image = UIImage(view: label)

    return UISwipeActionsConfiguration(actions: [action])
}

Answer 2

I recently found out a way to do this by using the button titleLabel instead of the image property, so that you keep the ability to have an action with text and image.

As you will see, we need to do something awkward...

func tableView(_ tableView: UITableView, willBeginEditingRowAt indexPath: IndexPath) {

    if #available(iOS 13.0, *) {
        for subview in tableView.subviews {
            if NSStringFromClass(type(of: subview)) == "_UITableViewCellSwipeContainerView" {
                for swipeContainerSubview in subview.subviews {
                    if NSStringFromClass(type(of: swipeContainerSubview)) == "UISwipeActionPullView" {
                        for case let button as UIButton in swipeContainerSubview.subviews {
                            button.titleLabel?.font = .systemFont(ofSize: 12)
                        }
                    }
                }
            }
        }
    } else {
        for subview in tableView.subviews {
            if NSStringFromClass(type(of: subview)) == "UISwipeActionPullView" {
                for case let button as UIButton in subview.subviews {
                    button.titleLabel?.font = .systemFont(ofSize: 12)
                }
            }
        }
    }
 }

Answer 3

Updated for Swift 5 & iOS 13

The following function allows you to set a font as well as a tint color to your swipe actions.

To get started, add an extension to UITableView .

extension UITableView {
    /// Iterates over all subviews of a `UITableView` instance and applies the supplied font to all labels withing the UISwipeAction's array.
    /// - Parameter font: The font that should be applied to the labels.
    /// - Parameter tintColor: The tint color that should be applied to image views and labels
    /// - Parameter ignoreFirst: Whether or not the first swipe action should be ignored when applying tints
    public func setSwipeActionFont(_ font: UIFont, withTintColor tintColor: UIColor? = nil, andIgnoreFirst ignoreFirst: Bool = false) {
        for subview in self.subviews {
            //Confirm that the view being touched is within a swipe container
            guard NSStringFromClass(type(of: subview)) == "_UITableViewCellSwipeContainerView" else {
                continue
            }

            //Re-iterate subviews and confirm that we are touching a swipe view
            for swipeContainerSubview in subview.subviews {
                guard NSStringFromClass(type(of: swipeContainerSubview)) == "UISwipeActionPullView" else {
                    continue
                }

                //Enumerate subviews and confirm that we are touching a button
                for (index, view) in swipeContainerSubview.subviews.filter({ $0 is UIButton }).enumerated() {
                    //Set Font
                    guard let button = view as? UIButton else {
                        continue
                    }
                    button.titleLabel?.font = font
                    
                    //Set Tint Conditionally (based on index)
                    guard index > 0 || !ignoreFirst else {
                        continue
                    }
                    button.setTitleColor(tintColor, for: .normal)
                    button.imageView?.tintColor = tintColor
                }
            }
        }
    }
}

Within your delegate, add the following functionality to your UITableViewDataSource.WillBeginEditing(UITableView, IndexPath) method. Replace the font and colour params as you need. Tint colour is optional.

self?.tableView.setSwipeActionFont(.systemFont(ofSize: 24.0, withTintColor: .systemRed)

Answer 4

FOR OBJECTIVE C

Create a method

- (UIImage *)createImageFromLabel:(UILabel *)label
{
    UIGraphicsBeginImageContext(label.bounds.size);

    [label.layer renderInContext:UIGraphicsGetCurrentContext()];;

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

    return image;
}

This method will return image from your label.

Now in tableview datasource method

- (UISwipeActionsConfiguration *)tableView:(UITableView *)tableView trailingSwipeActionsConfigurationForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UIContextualAction *action = [UIContextualAction contextualActionWithStyle:UIContextualActionStyleDestructive title:nil handler:^(UIContextualAction * _Nonnull action, __kindof UIView * _Nonnull sourceView, void (^ _Nonnull completionHandler)(BOOL)) {
        
        //Your code here
    }];

    action.backgroundColor = [UIColor redColor];

    // Create label as you want view for delete button
    UILabel *label = [[UILabel alloc] init];
    label.font = [UIFont systemFontSize:14];
    label.text = @"Your Text";
    label.textColor = [UIColor whiteColor];
    [label sizeToFit];
    UIImage *image =  [self createImageFromLabel:label];

    action.image = image;

    UISwipeActionsConfiguration *actions = [UISwipeActionsConfiguration configurationWithActions:@[action]];

    return actions;
}