WPF IsEnabled綁定

Question

如果值不同於550，則無法理解如何禁用文本框。如果初始值與550不同，則對所有值禁用該值，如果初始值等於550，則對所有值禁用該值。問題它是否會更新當我更改UI中的值。

這裏是我的XAML

<src:CustomTextBox VerticalAlignment = "Center" 
        Text="{Binding TrafoProperties.InsulationLevels.LightningImpulseVoltage, 
            UpdateSourceTrigger = PropertyChanged, 
            Mode = TwoWay,      
            ValidatesOnNotifyDataErrors = True, 
            NotifyOnValidationError = True}" 
        Validation.ErrorTemplate = "{StaticResource defaultErrorTemplate}" 
        IsEnabled="{Binding Path = TrafoProperties.InsulationLevels.IsEnabled, Mode = TwoWay}"/> 

和我的兩個propeteries

public double LightningImpulseVoltage 
{ 
    get { return _LightningImpulseVoltage; } 
    set 
    { 
     SetProperty(ref _LightningImpulseVoltage, value); 
     if (OnLightningImpulseVoltage != null) 
      OnLightningImpulseVoltage(); 
    } 
} 

public bool IsEnabled 
{ 
    get { return LightningImpulseVoltage == 550; } 
    set 
    { 
     OnPropertyChanged("LightningImpulseVoltage"); 
    } 
} 

我的SetProperty

protected bool SetProperty<T>(ref T storage, T value, [CallerMemberName] String propertyName = null) 
{ 
    if (object.Equals(storage, value)) 
     return false; 

    storage = value; 
    this.OnPropertyChanged(propertyName); 
    return true; 
    } 

而且我OnPropertyChanged

protected void OnPropertyChanged([CallerMemberName] string propertyName = null) 
{ 
    var eventHandler = this.PropertyChanged; 
    if (eventHandler != null) 
    { 
     eventHandler(this, new PropertyChangedEventArgs(propertyName)); 
    } 
} 

Answer 1

您必須使用IsEnabled，這取決於LightingImpulseVoltage。如果您希望綁定更新時LightingImpulseVoltage值的改變，你需要提高PropertyChanged在是的屬性設置，如下所示：

public double LightningImpulseVoltage 
{ 
    get { return _LightningImpulseVoltage; } 
    set 
    { 
     SetProperty(ref _LightningImpulseVoltage, value); 
     if (OnLightningImpulseVoltage != null) 
      OnLightningImpulseVoltage(); 
     OnPropertyChanged("IsEnabled"); 
    } 
}