WPF简单验证问题-设置自定义ErrorContent
本文关键字:设置 自定义 ErrorContent 问题 简单 验证 WPF | 更新日期: 2023-09-27 17:57:53
如果我有以下TextBox:
<TextBox Height="30" Width="300" Margin="10" Text="{Binding IntProperty,
NotifyOnValidationError=True}" Validation.Error="ContentPresenter_Error">
</TextBox>
这个在代码后面:
private void ContentPresenter_Error(object sender, ValidationErrorEventArgs e) {
MessageBox.Show(e.Error.ErrorContent.ToString());
}
如果我在文本框中输入字母"x",则弹出的消息为
无法转换值"x"
是否有自定义此消息的方法?
我不喜欢回答自己的问题,但似乎唯一的方法是实现ValidationRule,如下所示(其中可能有一些错误):
public class BasicIntegerValidator : ValidationRule {
public string PropertyNameToDisplay { get; set; }
public bool Nullable { get; set; }
public bool AllowNegative { get; set; }
string PropertyNameHelper { get { return PropertyNameToDisplay == null ? string.Empty : " for " + PropertyNameToDisplay; } }
public override ValidationResult Validate(object value, System.Globalization.CultureInfo cultureInfo) {
string textEntered = (string)value;
int intOutput;
double junkd;
if (String.IsNullOrEmpty(textEntered))
return Nullable ? new ValidationResult(true, null) : new ValidationResult(false, getMsgDisplay("Please enter a value"));
if (!Int32.TryParse(textEntered, out intOutput))
if (Double.TryParse(textEntered, out junkd))
return new ValidationResult(false, getMsgDisplay("Please enter a whole number (no decimals)"));
else
return new ValidationResult(false, getMsgDisplay("Please enter a whole number"));
else if (intOutput < 0 && !AllowNegative)
return new ValidationResult(false, getNegativeNumberError());
return new ValidationResult(true, null);
}
private string getNegativeNumberError() {
return PropertyNameToDisplay == null ? "This property must be a positive, whole number" : PropertyNameToDisplay + " must be a positive, whole number";
}
private string getMsgDisplay(string messageBase) {
return String.Format("{0}{1}", messageBase, PropertyNameHelper);
}
}
您可以使用ValidationRules。
例如,在我的案例中,当用户在十进制datagridtext列中输入无效值时,我可以用覆盖它,而不是默认消息"value cannot be converted"
<DataGridTextColumn x:Name="Column5" Header="{x:Static p:Resources.Waste_perc}" Width="auto">
<DataGridTextColumn.Binding>
<Binding Path="Waste" ValidatesOnDataErrors="True" UpdateSourceTrigger="LostFocus">
<Binding.ValidationRules>
<myLib:DecimalRule />
</Binding.ValidationRules>
</Binding>
</DataGridTextColumn.Binding>
</DataGridTextColumn>
这是十进制规则的代码:
public override ValidationResult Validate(object value, CultureInfo cultureInfo)
{
decimal convertedDecimal;
if (!decimal.TryParse((string)value, out convertedDecimal))
{
return new ValidationResult(false, "My Custom Message"));
}
else
{
return new ValidationResult(true, null);
}
}