WPF綁定文本框屬性的靜態類不更新

-1

我有三個文本框用於存儲數值和三個靜態類，我想綁定到文本框。我希望第三個文本框等於前兩個文本框的總和。我有一個具備所有這些屬性（只顯示爲簡單起見值）的非靜態類：WPF綁定文本框屬性的靜態類不更新

public class Field : PropertyValueChanged 
{ 
    private string _value; 

    public virtual string Value 
    { 
     get { return _value; } 
     set 
     { 
      if (value != _value) 
      { 
       _value = value; 
       NotifyPropertyChanged(); 
      } 
     } 
    } 
}

然後，我有三個靜態類：

public static class FirstValueField 
{ 
    public static Field FieldProperties; 

    static FirstValueField() 
    { 
     FieldProperties = new Field(); 
    } 
} 

public static class SecondValueField 
{ 
    public static Field FieldProperties; 

    static SecondValueField() 
    { 
     FieldProperties = new Field(); 
    } 
} 

public static class TotalField 
{ 
    public static Field FieldProperties = new Field(); 

    static TotalField() 
    { 
     FirstValueField.FieldProperties.PropertyChanged += TotalField_PropertyChanged; 
     SecondValueField.FieldProperties.PropertyChanged += TotalField_PropertyChanged; 
    } 

    private static void TotalField_PropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e) 
    { 
     double val1, val2; 
     if (FirstValueField.FieldProperties.Value == null) 
     { 
      val1 = 0; 
     } 
     else 
     { 
      val1 = Double.Parse(FirstValueField.FieldProperties.Value); 
     } 
     if (SecondValueField.FieldProperties.Value == null) 
     { 
      val2 = 0; 
     } 
     else 
     { 
      val2 = Double.Parse(SecondValueField.FieldProperties.Value); 
     } 
     FieldProperties.Value = (val1 + val2).ToString(); 
     MessageBox.Show("Changing TotalField to: " + FieldProperties.Value); 
    } 
}

我的XAML看起來像這樣：

<TextBox x:Name="FirstValueField" 
     Text="{Binding Source={x:Static local:FirstValueField.FieldProperties}, 
      Path=Value, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/> 

    <TextBox x:Name="SecondValueField" 
     Text="{Binding Source={x:Static local:SecondValueField.FieldProperties}, 
      Path=Value, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/> 

    <TextBox x:Name="TotalField" 
     Text="{Binding Source={x:Static local:TotalField.FieldProperties}, 
      Path=Value, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>

問題是TotalField.FieldProperties.Value正在更新，但不是文本框文本。我不確定有什麼問題？

來源

2017-05-27 Tim Romanski

您無法綁定到字段。你需要使它成爲一個屬性：

public static class FirstValueField 
{ 
    public static Field FieldProperties{get; set;} //<-- See this needs to be property 

    static FirstValueField() 
    { 
     FieldProperties = new Field(); 
    } 
}

對你的其他類做同樣的事情。

來源

2017-05-27 17:02:04 CodingYoshi

WPF綁定文本框屬性的靜態類不更新

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