WPF 使用MultiBinding ，TwoWay ，ValidationRule ，需要注意的事项
如： 以下是一个Textbox通过MultiBinding绑定到后台 的字段， 以及前台的一个radiobutton, 该textbox有个validaterule。
<TextBox x:Name="txtPatientWeight" TextWrapping="Wrap" Margin="3" MaxLength="5" TabIndex="6" BorderBrush="Black" Grid.Row="5" Grid.Column="1" Height="22" MinWidth="42" Tag="PatientWeight"
Visibility="{Binding DataContext, ElementName=window, Converter={StaticResource KeyToVisibilityConverter}, ConverterParameter=PatientWeight}">
<MultiBinding Mode="TwoWay" Converter="{StaticResource WeightConverter}" UpdateSourceTrigger="PropertyChanged">
<MultiBinding.ValidationRules>
<McsfPAFEContainee_ValidationRules:WeightValidationRule ValidatesOnTargetUpdated="True" ValidationStep="ConvertedProposedValue"/>
</MultiBinding.ValidationRules>
<Binding Path="PatientWeight"/>
<Binding Path="IsChecked" ElementName="rdoKg"/>
</MultiBinding>
<i:Interaction.Behaviors>
<McsfPAFEContainee_Behaviors:NumericTextBoxBehavior MinValue="0" MaxValue="300" />
</i:Interaction.Behaviors>
</TextBox>
////////////////////////
<RadioButton x:Name="rdoKg" Content="kg" GroupName="WeightMeasure" d:LayoutOverrides="GridBox" MinWidth="34" Margin="5,0,0,0" Tag="PatientWeight" HorizontalAlignment="Center">
<RadioButton.IsChecked>
<Binding Path="DataContext" Mode="TwoWay" ElementName="window" Converter="{StaticResource DefaultUnitConverter}" ConverterParameter="kg" UpdateSourceTrigger="PropertyChanged"></Binding>
</RadioButton.IsChecked>
</RadioButton>
private string patientWeight = "";//(0010,1030) Patient Weight PatientWeight DS unit kg
public string PatientWeight
{
get { return patientWeight; }
set
{
if (value == patientWeight)
{
return;
}
patientWeight = value;
OnPropertyChanged("PatientWeight");
}
}
public class WeightConverter : IMultiValueConverter
{
public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
if (null == values || 2 != values.Length )
{
return "";
}
string unit = "";
string temp = values[0].ToString();
if (String.IsNullOrEmpty(temp))
{
return "";
}
if (0 <= temp.IndexOf("lb"))
{
unit = "lb";
}
else if (0 <= temp.IndexOf("kg"))
{
unit = "kg";
}
else
{
return "";
}
string number = "";
number = temp.Substring(0, temp.IndexOf(unit));
//KG
if ((bool)values[1])
{
measurementUnit = "kg";
}
else //LB
{
measurementUnit = "lb";
}
return ConvertToTargetValue(number, unit, measurementUnit);
}
private string measurementUnit = "";
public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
{
string temp = value.ToString();
if (String.IsNullOrEmpty(temp))
{
return new object[]{DependencyProperty.UnsetValue, DependencyProperty.UnsetValue};
}
if (String.IsNullOrEmpty(measurementUnit))
{
measurementUnit = (PAFEContainee.MainDataContext as MainViewModel).PRCfgVM.IsDefaultKilogram ? "kg" : "lb";
}
object[] list = new object[2];
list[0] = value.ToString() + measurementUnit;
list[1] = measurementUnit.Equals("kg") ? "true" : "false";
return list;
}
private string ConvertToTargetValue(string before, string beforeUnit, string afterUnit)
{
string result = "";
if (beforeUnit.Equals(afterUnit))
{
return before;
}
switch (afterUnit)
{
case "lb":
result = ConvertKgToPound(before).ToString();
break;
case "kg":
result = ConvertPoundToKg(before).ToString();
break;
default:
break;
}
return result;
}
private double ConvertPoundToKg(string pound)
{
double kg = 0.4536 * double.Parse(pound);
return kg;
}
private double ConvertKgToPound(string kg)
{
double pound = 2.20 * double.Parse(kg);
return pound;
}
}
public override ValidationResult DoValidate(object value, CultureInfo cultureInfo)
{
try
{
//string field = value.ToString().Trim();
string field = (value as object[])[0].ToString();
string pattern = @"^([1-9]|[1-9][0-9]|[1-5][0-9][0-9]|600)((kg)|(lb))$";
Regex reg = new Regex(pattern, RegexOptions.IgnoreCase);
if (field.Length <= 0 || false == reg.IsMatch(field))
{
return new ValidationResult(false, "Please input a number, for example '60'");
}
else
{
return ValidationResult.ValidResult;
}
}
catch
{
return new ValidationResult(false, "Patient weight convert failed.");
}
}
https://muzizongheng.blog.csdn.net/
