Swift，标签在回调函数中不刷新

Question

我想在循环运行时更改/重新加载事件指示器上的标签。但我认为它不会重新加载，因为“self.netUtil.callWebservice(urlStr) {(data)”。

我的代码如下——————————————

     if netUtil.isConnectedToNetwork() == true
    {
        self.showActivityIndicator(self.view,message: "Synch is progress...")

            //Logic toc all Web Service
            var urlStr: String = "\(constants.SERVER_URL)"
            self.container.addSubview(self.lblProcess)
            self.netUtil.callWebservice(urlStr) {(data) -> Void in

            self.fileMgr.createFileDirectory("/Surveyor")
            self.filePath = self.fileMgr.createFile(self.fileMgr.getSurveyourPropListXmlName(""))

            self.fileMgr.writeFile(data, filenamePath: self.fileMgr.getSurveyourPropListXmlName(""))
            self.xmlNSData = data.dataUsingEncoding(NSUTF8StringEncoding)!

            self.beginParsing()
            self.loadPropertyMap()
            var unitCount = 0


                for Prop: Property in self.properties
                {

                    unitCount++

                    for view in self.view.subviews
                    {
                        if view is UILabel
                        {
                            view.removeFromSuperview()
                        }
                    }

                    /* refresh label code start here */
                     dispatch_async(dispatch_get_main_queue(), {
                        //Run UI Updates
                         self.unitCount++
                         println("unitCount \( self.unitCount)")
                        var totCount = self.properties.count
                        var message = "Synchronization \(self.unitCount)/\(totCount) buildings completed"
                        self.lblProcess.text = message
                        self.lblProcess.setNeedsDisplay()

                    })

                    /* refresh label code End here */

                    //Backup code to be shfted while pushing in web service
                    self.fileMgr.getSurveyorUnitFiles("", proCode: Prop.proCode as String, isCreateBackup: true)

                    //back up code ended
                    self.callUnitsWebservice(Prop.proCode as String)  //another web service cal

                }
             self.lblProcess.removeFromSuperview()

            self.hideActivityIndicator()
        }

附加 println 的输出

属性数量 > 10单位计数 1单位计数 2单位数 3单位数 4单位数 5单位数 6单位数 7单位数 8单位数 9单位数 10

如果我将标签放在循环之外，那么它会重新加载...... 我应该如何在循环中重新加载标签，以便它在每个循环兴奋时发生变化？

感谢您提前提供帮助

Answer 1

您只能从主线程刷新 UI。

self.netUtil.callWebservice(urlStr) {(data) -> Void in} 作为 block 运行，不在主线程中。

你必须在 block 内做这样的事情:

        //Logic synchronization all Web Service
        var urlStr: String = "\(constants.SERVER_URL)"

        //Add the view. Don't forget to remove it when the looping is done.
        self.container.addSubview(self.lblProcess)

        self.netUtil.callWebservice(urlStr) {(data) -> Void in    //I suspect this method to reason why my label is not refreshing

        self.beginParsing()
        var unitCount = 0

        for Prop: Property in self.properties
        {

             unitCount++

            for view in self.view.subviews
            {
                if view is UILabel
                {
                    view.removeFromSuperview()
                }
            }

            /* refresh label code start here */
            dispatch_async(dispatch_get_main_queue(), {
                    //Run UI Updates
                    var totCount = self.properties.count
                    var message = "Synchronization \(unitCount)/\(totCount) buildings completed"
                    self.lblProcess.text = message
                    self.lblProcess.setNeedsDisplay()
            })
            /* refresh label code End here */

            //Backup code to be shfted while pushing in web service
            self.fileMgr.getSurveyorUnitFiles("", proCode: Prop.proCode as String, isCreateBackup: true)

            //back up code ended
            self.callUnitsWebservice(Prop.proCode as String)  //another web service cal

        }

        self.hideActivityIndicator()
    }