防止删除一个空的函数发生未定义报错

demo/libs/framework/framework.js

@@ -4885,6 +4885,7 @@ var Emitter = (function () {
     Emitter.prototype.removeObserver = function (eventType, handler) {
         var messageData = this._messageTable.get(eventType);
         var index = messageData.findIndex(function (data) { return data.func == handler; });
+        if (index != -1)
             messageData.removeAt(index);
     };
     Emitter.prototype.emit = function (eventType, data) {

source/bin/framework.js

@@ -4885,6 +4885,7 @@ var Emitter = (function () {
     Emitter.prototype.removeObserver = function (eventType, handler) {
         var messageData = this._messageTable.get(eventType);
         var index = messageData.findIndex(function (data) { return data.func == handler; });
+        if (index != -1)
             messageData.removeAt(index);
     };
     Emitter.prototype.emit = function (eventType, data) {

source/src/Utils/Emitter.ts

@@ -34,6 +34,7 @@ class Emitter<T> {
     public removeObserver(eventType: T, handler: Function){
         let messageData = this._messageTable.get(eventType);
         let index = messageData.findIndex(data => data.func == handler);
+        if (index != -1)
             messageData.removeAt(index);
     }