Swift语言开发中，用模拟器运行的时候总是出现![Thread 1:EXC_BAD_INSTRUCTION(code=EXC_I386_INVOP,subcode=0x0)][1]这个错误，怎么解决？求助！
源程序：
import UIKit
class ViewController: UIViewController {
@IBOutlet var wv:UIWebView
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
wv.loadRequest(NSURLRequest(URL:NSURL(string:"http://jikexueyuan.com")))
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
