获取键盘焦点和隐藏键盘
获得焦点
迅速
textField.becomeFirstResponder()
Objective-C
[textField becomeFirstResponder];
辞职
迅速
textField.resignFirstResponder()
Objective-C
[textField resignFirstResponder];
textField.becomeFirstResponder()
[textField becomeFirstResponder];
textField.resignFirstResponder()
[textField resignFirstResponder];