解决文件查看工具可能出现崩溃的问题

https://bugly.qq.com/v2/crash-reporting/crashes/5dc2acc53e?pid=2

galaxy/galaxy/Classes/Modules/IntelligentService(服务中心)/MyCertificates(我的证书)/VM/YHFilePreviewTool.swift

@@ -10,9 +10,10 @@ import UIKit
 
 class YHFilePreviewTool: NSObject {
 
-    weak var targetVC: UIViewController!
+    weak var targetVC: UIViewController?
+    private var documentController: UIDocumentInteractionController?
     
-    init(targetVC: UIViewController!) {
+    init(targetVC: UIViewController?) {
         self.targetVC = targetVC
     }
     
@@ -50,13 +51,22 @@ class YHFilePreviewTool: NSObject {
     }
      
     func openXLSXFile(at fileURL: URL, fileName: String?) {
-        let controller = UIDocumentInteractionController(url: fileURL)
+        documentController = UIDocumentInteractionController(url: fileURL)
         // 设置标题显示
         if let fileName = fileName, !fileName.isEmpty {
-            controller.name = fileName
+            documentController?.name = fileName
         }
-        controller.delegate = self
-        DispatchQueue.main.async {
+        documentController?.delegate = self
+        guard let controller = documentController else {
+            printLog("Failed to create UIDocumentInteractionController")
+            return
+        }
+
+        DispatchQueue.main.async { [weak self] in
+            guard let self = self, let presentingVC = self.targetVC else {
+                printLog("Target view controller is not available")
+                return
+            }
             controller.presentPreview(animated: true)
         }
     }
@@ -64,6 +74,6 @@ class YHFilePreviewTool: NSObject {
 
 extension YHFilePreviewTool: UIDocumentInteractionControllerDelegate {
     func documentInteractionControllerViewControllerForPreview(_ controller: UIDocumentInteractionController) -> UIViewController {
-        return targetVC
+        return targetVC ?? UIViewController.current ?? UIViewController()
     }
 }