UITextField-Shake

// 调用方法，_textField将shake5次

[_textField shake:10 withDelta:5 andSpeed:0.04];

// 统一改变textfield边框颜色或者宽度的方法。

NSArray *fields = @[_textShake, _textSpeed, _textDelta, _textField];
[fields enumerateObjectsUsingBlock:^(UITextField *obj, NSUInteger idx, BOOL *stop){
    [obj.layer setBorderWidth:2];
    [obj.layer setBorderColor:[UIColor colorWithRed:49.0/255.0 green:186.0/255.0 blue:81.0/255.0 alpha:1].CGColor];
}];}