开发基于Pasteboard的应用：如何检查复制文本的来源应用？

Hey there! Great question—tracking clipboard source apps is totally feasible on Apple platforms, though the approach differs a bit between macOS and iOS/iPadOS. Let’s walk through practical, actionable steps for each:

macOS 实现方案（10.13+） #

macOS provides direct API access to the clipboard’s source application, making this straightforward.

步骤1：监听剪贴板变化 #

First, set up a listener for when the clipboard content changes using NSPasteboard.general's changeCount property or notifications:

import AppKit

class ClipboardMonitor {
    private var lastChangeCount = 0
    
    init() {
        startMonitoring()
    }
    
    func startMonitoring() {
        lastChangeCount = NSPasteboard.general.changeCount
        // Use a timer to check for changes, or observe the NSPasteboardChangedNotification
        Timer.scheduledTimer(withTimeInterval: 0.5, repeats: true) { [weak self] _ in
            self?.checkClipboard()
        }
    }
    
    private func checkClipboard() {
        let currentCount = NSPasteboard.general.changeCount
        guard currentCount != lastChangeCount else { return }
        lastChangeCount = currentCount
        
        // Get source app bundle ID
        if let sourceBundleID = NSPasteboard.general.sourceApplication {
            checkIfFromNonSpecifiedApp(sourceBundleID: sourceBundleID)
        }
    }
}

步骤2：验证来源应用是否为指定运行应用 #

Next, check if the source app is your target app, and confirm that app is actually running:

private func checkIfFromNonSpecifiedApp(sourceBundleID: String) {
    let targetBundleID = "com.yourcompany.YourSpecifiedApp" // Replace with your app's bundle ID
    
    // Check if target app is running
    let isTargetAppRunning = NSWorkspace.shared.runningApplications.contains { app in
        app.bundleIdentifier == targetBundleID
    }
    
    // If target app is running AND clipboard source is NOT it, you've got your case
    if isTargetAppRunning && sourceBundleID != targetBundleID {
        print("Clipboard content came from a non-specified running app!")
        // Do your logic here
    }
}

iOS/iPadOS 实现方案（14.0+） #

iOS has stricter sandbox rules, but starting from iOS 14, Apple added sourceBundleID to UIPasteboardItem, letting you get the source app's bundle ID.

步骤1：请求剪贴板权限 #

First, add the NSClipboardUsageDescription key to your Info.plist to explain why you need clipboard access (required for iOS 14+):

<key>NSClipboardUsageDescription</key>
<string>We need to check where your copied content comes from to improve your experience.</string>

步骤2：监听剪贴板变化并获取来源 #

Set up a listener for clipboard changes and retrieve the source bundle ID:

import UIKit

class ClipboardMonitor {
    private var lastChangeCount = 0
    
    init() {
        startMonitoring()
        // Observe UIPasteboardChangedNotification for immediate updates
        NotificationCenter.default.addObserver(self, selector: #selector(clipboardChanged), name: UIPasteboard.changedNotification, object: nil)
    }
    
    func startMonitoring() {
        lastChangeCount = UIPasteboard.general.changeCount
    }
    
    @objc private func clipboardChanged() {
        let currentCount = UIPasteboard.general.changeCount
        guard currentCount != lastChangeCount else { return }
        lastChangeCount = currentCount
        
        // Get source bundle ID from pasteboard items
        if let firstItem = UIPasteboard.general.items.first, let sourceBundleID = firstItem.sourceBundleID {
            checkIfFromNonSpecifiedApp(sourceBundleID: sourceBundleID)
        }
    }
}

步骤3：验证来源（注意iOS沙盒限制） #

On iOS, you can’t directly check if a third-party app is running due to sandbox restrictions. If your "specified app" is your own app, you can simply compare the source bundle ID to your app's ID:

private func checkIfFromNonSpecifiedApp(sourceBundleID: String) {
    let targetBundleID = Bundle.main.bundleIdentifier! // Your app's ID
    
    // If clipboard source is NOT your app, that's your case
    if sourceBundleID != targetBundleID {
        print("Clipboard content came from outside your app!")
        // Do your logic here
    }
    
    // For third-party specified apps:
    // You can't verify if they're running directly, but you can check if the source ID matches their bundle ID
    // Example:
    let thirdPartyTargetID = "com.othercompany.TargetApp"
    if sourceBundleID != thirdPartyTargetID {
        print("Clipboard content didn't come from the third-party target app")
    }
}

关键注意事项 #

• macOS Permissions: No special permissions are needed for NSPasteboard.sourceApplication, but if you need to interact with other apps' windows, you might need Accessibility permissions.
• iOS Limitations: Sandbox rules prevent checking if third-party apps are running. You can only confirm if the clipboard content came from a specific bundle ID, not whether that app is currently active/running.
• Edge Cases: Some apps might not provide a source bundle ID (e.g., system apps or older apps), so handle nil values gracefully.

内容的提问来源于stack exchange，提问作者Divya Patel