class Student : INotifyPropertyChanged, IDataErrorInfo{// 用于保存验证错误信息。key 保存所验证的字段名称；value 保存对应的字段的验证错误信息列表private Dictionary<String, List<String>> errors = new Dictionary<string, List<string>>();private const string NAME_ERROR = "name 不能包含空格";private const string ID_ERROR = "id 不能小于 10";private int age;public int Age{get { return age; }set{if (IsIdValid(value))age = value;elseage = 0;OnPropertyChanged("Age");}}private string stuName;public string StuName{get { return stuName; }set{IsNameValid(value);stuName = value;OnPropertyChanged("StuName");}}public bool IsIdValid(int value){bool isValid = true;if (value < 10){AddError("Age", ID_ERROR);isValid = false;}else{RemoveError("Age", ID_ERROR);}return isValid;}public bool IsNameValid(string value){bool isValid = true;if (String.IsNullOrEmpty(value)){AddError("StuName", NAME_ERROR);isValid = false;}else{RemoveError("StuName", NAME_ERROR);}return isValid;}public void AddError(string propertyName, string error){if (!errors.ContainsKey(propertyName))errors[propertyName] = new List<string>();if (!errors[propertyName].Contains(error))errors[propertyName].Add(error);}public void RemoveError(string propertyName, string error){if (errors.ContainsKey(propertyName) && errors[propertyName].Contains(error)){errors[propertyName].Remove(error);if (errors[propertyName].Count == 0)errors.Remove(propertyName);}}public string Error{get { return errors.Count > 0 ? "有验证错误" : ""; }}public string this[string propertyName]{get{if (errors.ContainsKey(propertyName))return string.Join(Environment.NewLine, errors[propertyName]);elsereturn null;}}public void OnPropertyChanged(string propertyName){if (PropertyChanged != null){PropertyChanged(this, new PropertyChangedEventArgs(propertyName));}}public event PropertyChangedEventHandler PropertyChanged;}

public class DataErrorInfoCommon{// 用于保存验证错误信息。key 保存所验证的字段名称；value 保存对应的字段的验证错误信息列表public Dictionary<String, List<String>> errors = new Dictionary<string, List<string>>();public string Error{get { return errors.Count > 0 ? "有验证错误" : ""; }}public string This(string propertyName){if (errors.ContainsKey(propertyName))return string.Join(Environment.NewLine, errors[propertyName]);elsereturn null;}#region IDataErrorInfo验证方法private const string REQUIRED = "不能为空";private const string NUMBER = "请输入数字";private const string LENGTH_CROSS = "长度超过限制{0}";/// <summary>/// 添加错误消息/// </summary>/// <param name="propertyName">属性名称</param>/// <param name="error">错误消息</param>public void AddError(string propertyName, string error){if (!errors.ContainsKey(propertyName))errors[propertyName] = new List<string>();if (!errors[propertyName].Contains(error))errors[propertyName].Add(error);}/// <summary>/// 移除错误消息/// </summary>/// <param name="propertyName">属性名称</param>/// <param name="error">错误消息</param>public void RemoveError(string propertyName, string error){if (errors.ContainsKey(propertyName) && errors[propertyName].Contains(error)){errors[propertyName].Remove(error);if (errors[propertyName].Count == 0)errors.Remove(propertyName);}}/// <summary>/// 判断是否为空/// </summary>/// <param name="propertyName">属性名称</param>/// <param name="value">属性值</param>/// <returns></returns>public bool IsEmpty(string propertyName, string value){bool isEmpty = false;if (String.IsNullOrWhiteSpace(value)){AddError(propertyName, REQUIRED);isEmpty = true;}elseRemoveError(propertyName, REQUIRED);return isEmpty;}/// <summary>/// 判断内容是否是数字/// </summary>/// <param name="propertyName">属性名称</param>/// <param name="value">属性值</param>/// <returns></returns>public bool IsNumber(string propertyName, string value){bool isNumber = true;int num = -1;if (!int.TryParse(value, out num)){AddError(propertyName, NUMBER);isNumber = false;}elseRemoveError(propertyName, NUMBER);return isNumber;}/// <summary>/// 判断长度是否超过限制/// </summary>/// <param name="propertyName">属性名称</param>/// <param name="value">属性值</param>/// <param name="length">长度限制</param>/// <returns></returns>public bool IsCrossLenght(string propertyName, string value, int length){bool isCross = false;if (value.Length > length){AddError(propertyName, string.Format(LENGTH_CROSS, length));isCross = true;}elseRemoveError(propertyName, string.Format(LENGTH_CROSS, length));return isCross;}#endregion}

 //定义验证类对象public DataErrorInfoCommon dataErrorCommon = null;//在构造函数中初始化
dataErrorCommon =new DataErrorInfoCommon();//使用private string stuName;public string StuName{get { dataErrorCommon.IsEmpty("StuName", stuName);return stuName; }set{dataErrorCommon.IsEmpty("StuName",value);stuName = value;OnPropertyChanged("StuName");}}        public event PropertyChangedEventHandler PropertyChanged;/// 属性改变通知事件/// </summary>/// <param name="propertyName">属性通知</param>public void OnPropertyChanged(string propertyName){if (PropertyChanged != null){PropertyChanged.Invoke(this, new PropertyChangedEventArgs(propertyName));}}public string Error{get { return dataErrorCommon.Error; }}public string this[string propertyName]{get{return dataErrorCommon.This(propertyName);}}