Blend 4中经常看到一个输入框，里面有值还有单位，当获取到焦点的时候，就只有值了，修改完值之后，失去焦点，单位又加上了。

class myTextbox : TextBox    {        private int _timeValue=100;        public int TimeValue        {            get { return _timeValue; }            set { _timeValue = value; }        }        public myTextbox()        {            this.Text = TimeValue.ToString()+" 秒";            GotFocus += myTextbox_GotFocus;            LostFocus += myTextbox_LostFocus;        }        void myTextbox_LostFocus(object sender, System.Windows.RoutedEventArgs e)        {            TimeValue = Convert.ToInt32(this.Text.ToString());            this.Text = TimeValue.ToString() + " 秒";        }        void myTextbox_GotFocus(object sender, System.Windows.RoutedEventArgs e)        {            this.Text = TimeValue.ToString();        }    }

这样就实现了...