wpf 验证方法

效果图，当放鼠标到文本框上会显示出错的提示。

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1、在对文本框绑定属性Count,并在绑定属性时添加NotifyOnValidationError=True,ValidatesOnExceptions=True，当通知更新源时会触发验证，如果验证失败则会触发Validation.Error事件，此事件是隧道事件，可以写在上一层对象中

   <Grid Validation.Error="Grid_Error">
        <TextBox Name="txt"  Text="{Binding Path=Count,UpdateSourceTrigger=PropertyChanged,NotifyOnValidationError=True,ValidatesOnExceptions=True}"/>
    </Grid>

2、验证过程放在属性的set中，如下MyValide,失败时抛出异常。

        private int c;

        public int Count
        {
            get { return c; }
            set
            {
                MyValide(value);
                c = value;
                if (PropertyChanged != null)
                {
                    PropertyChanged(this, new PropertyChangedEventArgs("Count"));
                }
            }
        }

        public void MyValide(int v)
        {
            if(Regex.Match(v.ToString(),@"^\d{6}$").Success==false)
            {
                throw new ArgumentException("请填写6个数字!");
            }
        }

3、如果抛出异常则有Error事件处理，在文本框上的toolTip属性中显示提示信息。

        private void Grid_Error(object sender, ValidationErrorEventArgs e)
        {
            if (Validation.GetErrors(txt).Count() > )
            {
                txt.ToolTip = Validation.GetErrors(txt)[].ErrorContent.ToString();
            }
            else
                txt.ToolTip = null;
        }