import UIKit
class ViewController: UIViewController ,UITextFieldDelegate,UITextViewDelegate,UIActionSheet Delegate,UIAlertViewDelegate{
override func viewDidLoad() {
super.viewDidLoad()
let textField:UITextField = UITextField(frame: CGRectMake(10,120,200,30))
textField.borderStyle = UITextBorderStyle.RoundedRect
textField.placeholder = "请输入用户名"
//文字大小超过文本框长度时自动缩小字号，而不是隐藏显示省略号
textField.adjustsFontSizeToFitWidth = true//当文字超出文本框宽度时，自动调整文字大小
textField.minimumFontSize = 14//最小可缩小的字号
textField.textAlignment = NSTextAlignment.Right
// textField.co ntentVerticalAlignment = .Bottom
textField.delegate = self;
self.view.addSubview(textField)
//textField.borderStyle = .None
//textField.background = UIImage(named: "lalala")
textField.clearButtonMode = UITextFieldViewMode.Always
textField.returnKeyType = UIReturnKeyType.Done
}
func textFieldShouldReturn(textField:UITextField) ->Bool {
//使文本框在界面打开时就获取焦点，并弹出输入键盘
textField.resignFirstResponder()
print(textField.text)
return true
}
}