add some method

ios/Classes/Module/BaseServiceManager.swift

@@ -0,0 +1,50 @@
+//
+//  BaseServiceManager.swift
+//  flutter_openim_sdk
+//
+//  Created by willem on 2021/10/9.
+//
+
+import Flutter
+import OpenIMCore
+import UIKit
+
+public typealias ImHandler = (_ methodCall: FlutterMethodCall, _ result: @escaping FlutterResult) -> Void
+
+open class BaseServiceManager {
+    public let channel: FlutterMethodChannel
+    private var methodHandlers: [String: ImHandler] = [:]
+    
+    public init(channel: FlutterMethodChannel) {
+        self.channel = channel
+        self.registerHandlers()
+    }
+    
+    public func handleMethod(call: FlutterMethodCall, result: @escaping FlutterResult) {
+        let method: String = call.method
+        guard let handler = methodHandlers[method] else {
+            print("Handle MethodName Error: \(typeName(self))'s method: [\(method)] not found")
+            return
+        }
+        handler(call, result)
+    }
+    
+    public subscript(_ key: String) -> ImHandler? {
+        get {
+            methodHandlers[key]
+        }
+        set {
+            methodHandlers[key] = newValue
+        }
+    }
+    
+    public func registerHandlers() {
+        
+    }
+    
+    public func callBack(_ result: @escaping FlutterResult, _ content: Any? = nil) {
+        safeMainAsync {
+            result(content)
+        }
+    }
+}