segue没有立即被召唤

Question

I have a view controller A and it has a table list created dynamically with cells when calling didselectcell as

func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {

    let cell = tableView.cellForRowAtIndexPath(indexPath)
    if(cell?.tag == 1){
    performSegueWithIdentifier("profile", sender: self)
        print("perform segue for favourite")
    }

and i am calling prepare for segue like this and saving the variable the variable is available in 2nd view controller

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
     if(segue == "profile"){
     let vc = segue.destinationViewController as! MembersViewController
                    vc.title = " "
  }

when i run the app it takes hardly more than 25 sec [ the second view controller has collectionview] any idea of doing it faster

Answer 1

I solved this by calling dispatch_async function it moves immediately to next page and the next page also has for loop in viewwillappear thanks @rakeshbs got answer from this link

func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {

let cell = tableView.cellForRowAtIndexPath(indexPath)
if(cell?.tag == 1){
dispatch_async(dispatch_get_main_queue(), {
            self.performSegueWithIdentifier("profile", sender:self)
        })
}

Answer 2

There are a few things wrong with this. Change your didSelectRow method to this.

func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
    if(indexPath.row == 0) {
        performSegueWithIdentifier("profile", sender: nil)
    }
}

You can fix your didSelectRowAtIndexPath method to remove needing to grab the cell. It has a reference to the cell's index already, which is what you were grabbing.

Also, your prepareForSegue method can be improved as follows:

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if(segue.identifier == "profile") {
        let vc = segue.destinationViewController as? MembersViewController
        vc?.title = "New Title"
    }
}

You should never need to call dispatch_async with something like this, especially in Swift, unless you're already on a Background thread.

Before using the UITableView object and its UITableViewDelegate and UITableViewDataSource components, I suggest you muck about in an Xcode Playground, and read the Apple Documentation carefully to understand how everything works.