.net core 将IDataErrorInfo替换为INotifyDataErrorInfo
我有一个名为.net core 将IDataErrorInfo替换为INotifyDataErrorInfo,.net-core,idataerrorinfo,inotifydataerrorinfo,.net Core,Idataerrorinfo,Inotifydataerrorinfo,我有一个名为Person的类,它有两个属性FirstName,LastName,两个构造函数,一个ICommand,以及INotifyPropertyChanged和IDataErrorInfo所需的常用内容: class Person : ObservableCollection<Person>, INotifyPropertyChanged, IDataErrorInfo { string firstName, lastName; #region Propert
Person
的类,它有两个属性FirstName
,LastName,
两个构造函数
,一个ICommand
,以及INotifyPropertyChanged
和IDataErrorInfo
所需的常用内容:
class Person : ObservableCollection<Person>, INotifyPropertyChanged, IDataErrorInfo
{
string firstName, lastName;
#region Properties
[Required(ErrorMessage = "First Name is Required")]
[RegularExpression("test", ErrorMessage = "It's to be test")]
public string FirstName {
get => firstName;
set { firstName = value; OnPropertyChanged(); }
}
[Required]
[RegularExpression("test", ErrorMessage = "It also has to be test")]
public string LastName {
get => lastName;
set { lastName = value; OnPropertyChanged(); }
}
#endregion Properties
#region Constructors
public Person(){
AddToList = new Command(CanAdd, Add);
}
public Person(string fName, string lName){
FirstName = fName;
LastName = lName;
}
#endregion Constructors
#region Command
public ICommand AddToList { get; set; }
bool CanAdd(object para) => Validator.TryValidateObject(this, new ValidationContext(this), null, true);
void Add(object para){
Add(new Person(FirstName, LastName));
FirstName = LastName = null;
}
#endregion Command
#region INotifyPropertyChanged
public new event PropertyChangedEventHandler PropertyChanged;
void OnPropertyChanged([CallerMemberName] string name = "") => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));
#endregion INotifyPropertyChanged
#region IDataErrorInfo
public string Error => null;
public string this[string columnName] {
get {
var ValidationResults = new List<ValidationResult>();
if (Validator.TryValidateProperty(
GetType().GetProperty(columnName).GetValue(this),
new ValidationContext(this) { MemberName = columnName },
ValidationResults
)) return null;
return ValidationResults.First().ErrorMessage;
}
}
#endregion IDataErrorInfo
}
它可以工作,如果名字和姓氏无效,我会收到错误消息,只要名字和姓氏无效,按钮就会保持禁用状态。我只想将
IDataErrorInfo
部分替换为INotifyDataErrorInfo
。我必须在Person
类和xaml
中进行哪些更改才能保持相同的功能?每次引发ErrorsChanged
事件时,框架都会调用GetErrors
。由于有一个hasrerrors
属性,每当出现任何验证错误时,该属性应返回true
,因此在属性设置器中进行验证并将验证错误缓存在字典中是有意义的
请参考以下示例实现:
class Person : ObservableCollection<Person>, INotifyPropertyChanged, INotifyDataErrorInfo
{
string firstName, lastName;
#region Properties
[Required(ErrorMessage = "First Name is Required")]
[RegularExpression("test", ErrorMessage = "It's to be test")]
public string FirstName
{
get => firstName;
set { firstName = value; OnPropertyChanged(); Validate(); }
}
[Required]
[RegularExpression("test", ErrorMessage = "It also has to be test")]
public string LastName
{
get => lastName;
set { lastName = value; OnPropertyChanged(); Validate(); }
}
#endregion Properties
#region Constructors
public Person()
{
AddToList = new Command(CanAdd, Add);
Validate(nameof(FirstName));
Validate(nameof(LastName));
}
public Person(string fName, string lName)
{
FirstName = fName;
LastName = lName;
}
#endregion Constructors
#region Command
public ICommand AddToList { get; set; }
bool CanAdd(object para) => _validationResults.Count == 0;
void Add(object para)
{
base.Add(new Person(FirstName, LastName));
FirstName = LastName = null;
}
#endregion Command
#region INotifyPropertyChanged
public new event PropertyChangedEventHandler PropertyChanged;
void OnPropertyChanged([CallerMemberName] string name = "") => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));
#endregion INotifyPropertyChanged
#region INotifyDataErrorInfo
private readonly Dictionary<string, List<ValidationResult>> _validationResults = new Dictionary<string, List<ValidationResult>>();
public bool HasErrors => _validationResults.Count > 0;
public event EventHandler<DataErrorsChangedEventArgs> ErrorsChanged;
public System.Collections.IEnumerable GetErrors(string propertyName)
{
if (_validationResults.TryGetValue(propertyName, out List<ValidationResult> validationResults))
return new string[1] { validationResults.First().ErrorMessage };
return null;
}
private void Validate([CallerMemberName]string propertyName = "")
{
var ValidationResults = new List<ValidationResult>();
if (Validator.TryValidateProperty(typeof(Person).GetProperty(propertyName).GetValue(this),
new ValidationContext(this) { MemberName = propertyName }, ValidationResults))
{
_validationResults.Remove(propertyName);
}
else
{
_validationResults[propertyName] = ValidationResults;
}
ErrorsChanged?.Invoke(this, new DataErrorsChangedEventArgs(propertyName));
}
#endregion
}
类人员:ObservableCollection、INotifyPropertyChanged、INotifyDataErrorInfo
{
字符串firstName,lastName;
#区域属性
[必需(ErrorMessage=“需要名字”)]
[RegularExpression(“test”,ErrorMessage=“待测试”)]
公共字符串名
{
get=>firstName;
设置{firstName=value;OnPropertyChanged();Validate();}
}
[必需]
[RegularExpression(“test”,ErrorMessage=“它也必须被测试”)]
公共字符串姓氏
{
get=>lastName;
设置{lastName=value;OnPropertyChanged();Validate();}
}
#端域属性
#区域构造函数
公众人士()
{
AddToList=新命令(CanAdd,Add);
验证(名字(名字));
验证(nameof(LastName));
}
公众人物(字符串fName,字符串lName)
{
FirstName=fName;
LastName=lName;
}
#端域构造函数
#地区司令部
公共ICommand AddToList{get;set;}
bool CanAdd(对象参数)=>\u validationResults.Count==0;
无效添加(对象段)
{
base.Add(新人物(名字、姓氏));
FirstName=LastName=null;
}
#endregion命令
#区域inotifyproperty已更改
公共新事件属性ChangedEventHandler属性Changed;
void OnPropertyChanged([CallerMemberName]string name=”“)=>PropertyChanged?.Invoke(这是新的PropertyChangedEventArgs(名称));
#endregion InotifyProperty已更改
#区域INotifyDataErrorInfo
专用只读词典_validationResults=new Dictionary();
public bool HasErrors=>\u validationResults.Count>0;
公共事件事件处理程序错误更改;
public System.Collections.IEnumerable GetErrors(字符串propertyName)
{
if(_validationResults.TryGetValue(propertyName,out List validationResults))
返回新字符串[1]{validationResults.First().ErrorMessage};
返回null;
}
私有void验证([CallerMemberName]字符串propertyName=”“)
{
var ValidationResults=新列表();
if(Validator.TryValidateProperty)(typeof(Person).GetProperty(propertyName).GetValue)(this),
新的ValidationContext(this{MemberName=propertyName},ValidationResults))
{
_validationResults.Remove(propertyName);
}
其他的
{
_validationResults[propertyName]=validationResults;
}
ErrorsChanged?.Invoke(这是新的DataErrorsChangedEventArgs(propertyName));
}
#端区
}
不知道它是否好,但如果我只是用以下内容替换IDataErrorInfo
区域:
#region IDataErrorInfo
public bool HasErrors => true;
public event EventHandler<DataErrorsChangedEventArgs> ErrorsChanged;
public IEnumerable GetErrors(string propertyName)
{
var ValidationResults = new List<ValidationResult>();
if (Validator.TryValidateProperty(GetType().GetProperty(propertyName).GetValue(this),
new ValidationContext(this) { MemberName = propertyName }, ValidationResults))
return null;
return new string[1] { ValidationResults.First().ErrorMessage };
}
#endregion IDataErrorInfo
#地区IDataErrorInfo
公共bool hasrerrors=>true;
公共事件事件处理程序错误更改;
公共IEnumerable GetErrors(字符串propertyName)
{
var ValidationResults=新列表();
if(Validator.TryValidateProperty(GetType().GetProperty(propertyName).GetValue)(this),
新的ValidationContext(this{MemberName=propertyName},ValidationResults))
返回null;
返回新字符串[1]{ValidationResults.First().ErrorMessage};
}
#IDataErrorInfo端区
不要触摸任何其他部件,它也可以工作 它比IDataErrorInfo更复杂!使用此实现,您的模型始终处于错误状态,因为hasrerrors
始终返回true
@mm8,只要我在TextBox
两个文本框中都键入test
,错误就会消失,按钮状态也会改变,但是hasrerrors
属性仍然返回true
,从纯实现的角度来看,这很奇怪。@mm8,在GetErrors
之外声明ValidationResults
和ValidationResults.Count>0
在hasrerrors
中声明可能会解决问题,对吗?请参阅我的答案以获取示例。
#region IDataErrorInfo
public bool HasErrors => true;
public event EventHandler<DataErrorsChangedEventArgs> ErrorsChanged;
public IEnumerable GetErrors(string propertyName)
{
var ValidationResults = new List<ValidationResult>();
if (Validator.TryValidateProperty(GetType().GetProperty(propertyName).GetValue(this),
new ValidationContext(this) { MemberName = propertyName }, ValidationResults))
return null;
return new string[1] { ValidationResults.First().ErrorMessage };
}
#endregion IDataErrorInfo