fix ios & macos

ios/Flutter/AppFrameworkInfo.plist

@@ -21,6 +21,6 @@
   <key>CFBundleVersion</key>
   <string>1.0</string>
   <key>MinimumOSVersion</key>
-  <string>12.0</string>
+  <string>14.0</string>
 </dict>
 </plist>

ios/Runner/AppDelegate.swift

@@ -3,7 +3,7 @@ import UIKit
 import UniformTypeIdentifiers
 
 @UIApplicationMain
-@objc class AppDelegate: FlutterAppDelegate {
+@objc class AppDelegate: FlutterAppDelegate, UIDocumentPickerDelegate {
   var flutterResult: FlutterResult?
   var directoryPath: URL!
 

macos/Runner/AppDelegate.swift

@@ -34,25 +34,25 @@ class AppDelegate: FlutterAppDelegate {
       }
     }
 
-    func getDirectoryPath() {
+  func getDirectoryPath() {
       let openPanel = NSOpenPanel()
       openPanel.canChooseDirectories = true
       openPanel.canChooseFiles = false
       openPanel.allowsMultipleSelection = false
 
       openPanel.begin { (result) in
-        if result == .OK {
-          self.directoryPath = openPanel.urls.first
-          if !self.directoryPath?.startAccessingSecurityScopedResource() ?? false {
-            self.flutterResult?(nil)
-            return
+          if result == .OK {
+              self.directoryPath = openPanel.urls.first
+              if let directoryPath = self.directoryPath, !directoryPath.startAccessingSecurityScopedResource() {
+                  self.flutterResult?(nil)
+                  return
+              }
+              self.flutterResult?(self.directoryPath?.path)
+          } else {
+              self.flutterResult?(nil)
           }
-          self.flutterResult?(self.directoryPath?.path)
-        } else {
-          self.flutterResult?(nil)
-        }
       }
-    }
+  }
 
   override func applicationShouldTerminateAfterLastWindowClosed(_ sender: NSApplication) -> Bool {
     return true