使用FBSDK 4.32.0的iOS Facebook登录崩溃求助

Hey there, let's tackle this persistent crash you're seeing with FBSDK 4.32.0 across multiple iOS versions. Based on your code snippet and common issues with older FBSDK releases, here are the most likely fixes:

Common Causes of the Crash #

• Force-unwrapping nil values: Your code uses result! which will crash if the login result is nil (e.g., user cancels login, network failure).
• Outdated FBSDK version: 4.32.0 is a very old release (circa 2018) with known compatibility bugs that affect both older and newer iOS versions.
• Missing Info.plist configurations: Facebook login requires specific URL schemes and permissions in your app's Info.plist—omitting these can cause unexpected crashes.

Step-by-Step Solutions #

1. Fix Force-Unwrapping in Your Login Code #

The biggest red flag in your snippet is the forced unwrap of result!. Replace this with safe optional binding to avoid runtime crashes. Here's the revised code:

@IBAction func didTapLogainAction(_ sender: Any) {
    let fbLoginManager = FBSDKLoginManager()
    fbLoginManager.logIn(withReadPermissions: ["email"], from: self) { (result, error) in
        // Handle errors first
        guard error == nil else {
            print("Facebook Login Error: \(error!.localizedDescription)")
            return
        }
        
        // Safely unwrap the login result
        guard let fbLoginResult = result else {
            print("Login cancelled or result unavailable")
            return
        }
        
        // Check if email permission was granted
        if fbLoginResult.grantedPermissions.contains("email") {
            // Access the token and fetch user data if needed
            guard let accessToken = FBSDKAccessToken.current() else {
                print("No valid access token found")
                return
            }
            
            // Example: Fetch user profile via Graph API
            let graphRequest = FBSDKGraphRequest(graphPath: "me", parameters: ["fields": "id, name, email"])
            graphRequest?.start(completionHandler: { (connection, graphResult, graphError) in
                guard graphError == nil else {
                    print("Graph API Error: \(graphError!.localizedDescription)")
                    return
                }
                print("User Profile Data: \(graphResult ?? [:])")
            })
        } else {
            print("Email permission not granted by user")
        }
    }
}

2. Upgrade to a Newer FBSDK Version #

4.32.0 is no longer supported and has unresolved bugs. Upgrading to a stable, recent version will resolve most compatibility issues. Here's how:

• If using CocoaPods, update your Podfile:

  pod 'FBSDKCoreKit', '~> 17.0'
  pod 'FBSDKLoginKit', '~> 17.0'
  

• Run pod update in your terminal to install the latest versions.

3. Verify Info.plist Configurations #

Ensure your app's Info.plist includes these critical entries:

• Add FacebookAppID (string value = your Facebook App ID) and FacebookDisplayName (string value = your app's public name).
• Add an array key LSApplicationQueriesSchemes with the following items:
  • fbapi
  • fb-messenger-share-api
  • fbauth2
  • fbshareextension
• Add a URL types array with a dictionary containing:
  • URL Schemes array with your Facebook URL scheme (format: fb<YOUR_APP_ID>, e.g., fb1234567890)

Additional Debugging Tip #

Check your Xcode crash logs for the exact call stack—this will pinpoint whether the crash is happening in your code, FBSDK's internal logic, or due to missing configurations.

内容的提问来源于stack exchange，提问作者Manikandan