更新 iOS 平台内存警告插件，支持多个监听

uni_modules/uni-memorywarning/utssdk/app-ios/index.uts

@@ -3,35 +3,50 @@ import { UIApplication } from "UIKit"
 import { Selector } from "ObjectiveC"
 
 class MemoryWarningTool {
-	static listener: UTSCallback | null;
+	static listeners: UTSCallback[] = []
 	
 	// 监听内存警告
-	static listenMemoryWarning(callback: UTSCallback | null) {
-		this.listener = callback
+	static listenMemoryWarning(callback: UTSCallback) {
 		
-		// 注册监听内存警告通知事件及设置回调方法
-		// target-action 回调方法需要通过 Selector("方法名") 构建
-		const method = Selector("receiveMemoryWarning")
-		NotificationCenter.default.addObserver(this, selector = method, name = UIApplication.didReceiveMemoryWarningNotification, object = null)
+		// 只有首次才需要注册监听事件
+		if (this.listeners.length == 0) {
+			// 注册监听内存警告通知事件及设置回调方法
+			// target-action 回调方法需要通过 Selector("方法名") 构建
+			const method = Selector("receiveMemoryWarning")
+			NotificationCenter.default.addObserver(this, selector = method, name = UIApplication.didReceiveMemoryWarningNotification, object = null)
+		}
+		this.listeners.push(callback)
 	}
 	
 	// 内存警告回调的方法
 	// target-action 的方法前需要添加 @objc 前缀
 	@objc static receiveMemoryWarning() {
 		// 触发回调
-		this.listener?.({})
+		this.listeners.forEach(listener => {
+			listener({})
+		})
 	}
 	
 	// 移除监听事件
 	static removeListen(callback: UTSCallback | null) {
-		this.listener = null
-		NotificationCenter.default.removeObserver(this)
-		callback?.({})
+		// 移除所有监听
+		if (callback == null) {
+			this.listeners = []
+			// 移除监听事件
+			NotificationCenter.default.removeObserver(this)
+			return
+		}
+		
+		// 清除指定回调
+		const index = this.listeners.indexOf(callback!)
+		if (index > -1) {
+		    this.listeners.splice(index, 1)
+		}
 	}
 }
 
 // 开启监听内存警告
-export function onMemoryWarning(callback: UTSCallback | null) {
+export function onMemoryWarning(callback: UTSCallback) {
 	MemoryWarningTool.listenMemoryWarning(callback)
 }