Swift --下一响应者

通过下一响应者得到UITextField、UITextField

var nextRes = self.nextResponder()! as UIResponder
            repeat{
// 
                if ((nextRes.isKindOfClass(UITextView))){

                    let t = nextRes as! UITextView
                    t.resignFirstResponder()
                    t.text = ""
                    return
                }
                if(nextRes.isKindOfClass(UITextField)){
                    let t = nextRes as! UITextField
                    t.text = ""
                    t.resignFirstResponder()
                    return
                }
                nextRes = nextRes.nextResponder()!
            }while(true)

第二中写法：

 var nextRes = self.nextResponder()

            while(nextRes != nil){
                if(nextRes!.isKindOfClass(UITextView)){
                    let root = nextRes as! UITextView
                    root.resignFirstResponder()
                    return
                }

                if(nextRes!.isKindOfClass(UITextField)){
                    let root = nextRes as! UITextField
                    root.resignFirstResponder()
                    return
                }

                nextRes = nextRes?.nextResponder()

            }