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我遇到了IDataErrorInfo
多次被解雇的问题。为什么IDataErrorInfo多次触发?
Transaction Class
public class Transaction : INotifyPropertyChanged, INotifyPropertyChanging, IDataErrorInfo
{
private Double? _transAmount;
[Column(DbType = "decimal(19,4)")]
public Double? TransAmount
{
get { return _transAmount; }
set
{
if (_transAmount != value)
{
NotifyPropertyChanging("TransAmount");
_transAmount = value;
NotifyPropertyChanged("TransAmount");
}
}
}
#region INotifyPropertyChanged Members
public event PropertyChangedEventHandler PropertyChanged;
// Used to notify that a property changed
private void NotifyPropertyChanged(string propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
#endregion
#region INotifyPropertyChanging Members
public event PropertyChangingEventHandler PropertyChanging;
// Used to notify that a property is about to change
private void NotifyPropertyChanging(string propertyName)
{
if (PropertyChanging != null)
{
PropertyChanging(this, new PropertyChangingEventArgs(propertyName));
}
}
#endregion
#region Data Validation
public string Error { get { return null; } }
public string this[string property]
{
get
{
switch (property)
{
case "TransAmount":
if (TransAmount != null)
{
double value;
bool valid = double.TryParse(TransAmount.ToString(), out value);
if (!valid) { return TransAmount.ToString() + " is not a valid number"; }
else if (value <= 0) { return "Dollar amount must be greater than $0.00"; }
}
return null;
default:
return null;
}
}
}
#endregion
}
和XAML
<toolkit:PhoneTextBox Grid.Row="1" Grid.Column="1" HorizontalAlignment="Stretch"
x:Name="txtAmount" Width="Auto"
Text="{Binding TransAmount, Mode=TwoWay, NotifyOnValidationError=True, StringFormat=\{0:c\}, ValidatesOnDataErrors=True, ValidatesOnExceptions=True}"
BindingValidationError="txtAmount_BindingValidationError" InputScope="CurrencyAmount"
GotFocus="txtAmount_GotFocus"
LostFocus="txtAmount_LostFocus">
</toolkit:PhoneTextBox>
我不知道的格局,但验证方法被击中的2-3倍?为什么?
编辑1 正在txtAmount_LostFocus事件中设置值TransAmount。
编辑2 加入WP7标签
它不应该不管有多少次火灾。造成什么问题? – Bryant
实际上WPF验证框架并不“保证”整个“依赖”框架的单一验证通行证。尝试提高您的验证代码速度。 –
@Bryant - 这是在WP7上(只是添加了标签),我不知道如何向用户展示错误。为了看到一个错误,我在上面的文本框中添加了一个事件处理函数'BindingValidationError'。这会弹出一个消息框,显示IDataErrorInfo返回的错误的内容。也许这是一个不正确的实现。 –