HarmonyOS构造函数传入箭头函数,并立即执行 但是并未生效

constructor(url:string|Resource,count:number, instanceFun:(web:GZWebview)=>void) { 
  super(); 
  this.url = url 
  this.count = count 
  instanceFun(this); 
}

instanceFun: (web: GZWebview) => void = (web: GZWebview) => { 
  this.webInstance = web 
  this.registerFunction('setTitleBar',this.setTitleBar) 
} 
registerFunction(name:string,callback:Function){ 
  this.webInstance?.jsbridge.registerHandler(name,callback); 
} 
setTitleBar(name:string,func:Function){ 
  if (func) { 
    let rec:Record<string,BridgeSupportTypes> = {}; 
    rec['code'] = 0; 
    rec['msg'] = '成功'; 
    func(rec); 
  } 
} 
build() { 
  RelativeContainer() { 
    Column() { 
      GZWebview({ url: this.url ,count:this.count ,instanceFun:this.instanceFun})//,webviewController:this.webviewController    // 
        .backgroundColor(Color.Red) 
        .width('100%') 
        .height('100%') 
    }instanceFun: (web: GZWebview) => void = (web: GZWebview) => { 
      this.webInstance = web 
      this.registerFunction('setTitleBar',this.setTitleBar) 
    } 
    registerFunction(name:string,callback:Function){ 
      this.webInstance?.jsbridge.registerHandler(name,callback); 
    } 
    setTitleBar(name:string,func:Function){ 
      if (func) { 
        let rec:Record<string,BridgeSupportTypes> = {}; 
        rec['code'] = 0; 
        rec['msg'] = '成功'; 
        func(rec); 
      } 
    } 
    build() { 
      RelativeContainer() { 
        Column() { 
          GZWebview({ url: this.url ,count:this.count ,instanceFun:this.instanceFun})//,webviewController:this.webviewController    // 
            .backgroundColor(Color.Red) 
            .width('100%') 
            .height('100%') 
        }