Swift 3.3+Xcode9.3使用YPDrawSignatureView遇Thread 1: signal SIGABRT错误

Hey Johnny, let's work through that SIGABRT error you're hitting—this almost always boils down to a setup/connection issue rather than core code logic. Let's go through the most likely fixes step by step:

1. Fix the Custom View Setup in Storyboard #

This is probably the root cause: you mentioned adding a UIImage control, but YPDrawSignatureView is a custom UIView subclass, not a UIImageView. Here's how to correct this:

• Open Main.storyboard, delete the UIImageView you added.
• Drag a plain UIView onto your view controller's canvas instead.
• Select this new UIView, open the Identity Inspector (right-hand panel, third tab), and set its Class to YPDrawSignatureView. Make sure the Module dropdown is set to your project's target (if you have multiple targets).
• Reconnect this custom view to your signatureView IBOutlet in ViewController.swift (right-click the outlet in code and drag to the view in storyboard to re-establish the link).

Also, double-check for broken IBOutlets: right-click signatureView in your code—if you see any red-highlighted connections, delete them and re-link properly.

2. Verify YPDrawSignatureView is Added to Your Target #

If Xcode isn't compiling the YPDrawSignatureView.swift file, it'll throw a runtime error when trying to instantiate the class:

• Select the YPDrawSignatureView.swift file in your project navigator.
• Open the File Inspector (right-hand panel, first tab).
• Under Target Membership, ensure your main project target is checked. If it's not, tick the box and recompile.

3. Correct Delegate Setup #

You implemented YPSignatureDelegate, but you need to assign the delegate to your signature view to avoid potential crashes or missing callbacks:
Add this line to your viewDidLoad() method:

signatureView.delegate = self

Also, confirm that the YPSignatureDelegate protocol is marked with @objc (check the library's code):

@objc protocol YPSignatureDelegate: NSObjectProtocol {
    // Delegate methods here
}

Without @objc, Swift 3.3 might not properly recognize the delegate methods, leading to runtime issues.

4. Check Swift Version Compatibility #

YPDrawSignatureView might have Swift 4+ syntax that doesn't play nice with Swift 3.3. If you see compile errors in the library file, adjust these common differences:

• Replace @objcMembers with explicit @objc markers on individual methods/properties.
• Fix parameter label changes (Swift 3 uses external labels more strictly than later versions).
• Ensure all UIKit imports are present and correct.

Corrected Sample Code #

Here's a cleaned-up version of your view controller code with proper setup:

import UIKit

class ViewController: UIViewController, YPSignatureDelegate {
    @IBOutlet weak var signatureView: YPDrawSignatureView!
    @IBOutlet weak var clearButton: UIButton!
    @IBOutlet weak var saveButton: UIButton!
    @IBOutlet weak var signaturePreviewImage: UIImageView! // For displaying saved signature

    override func viewDidLoad() {
        super.viewDidLoad()
        // Set up signature view properties and delegate
        signatureView.delegate = self
        signatureView.strokeColor = .black
        signatureView.lineWidth = 2.0
    }

    // Clear signature action
    @IBAction func clearSignatureTapped(_ sender: UIButton) {
        signatureView.clear()
        signaturePreviewImage.image = nil
    }

    // Save signature action
    @IBAction func saveSignatureTapped(_ sender: UIButton) {
        if let signatureImage = signatureView.getSignature() {
            signaturePreviewImage.image = signatureImage
            // Add code here to save/upload the image if needed
        }
    }

    // Implement delegate method (optional, if required by the protocol)
    func signatureDidChange(_ view: YPDrawSignatureView) {
        print("Signature updated")
    }
}

Start with step 1 first—mixing up the view type is the most common reason for this SIGABRT error in your setup.

内容的提问来源于stack exchange，提问作者Johnny