Question

我有三个用于存储数值的文本框，以及三个带有我希望绑定到文本框的属性的静态类。我希望第三个文本框等于前两个文本框的总和。我有一个非静态类，它具有所有这些属性（为简单起见，只显示了值）：

public class Field : PropertyValueChanged
{
    private string _value;

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

然后我有三个静态类：

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看起来像这样：

    <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}"/>

问题是TotalField.FieldProperties.Value正在更新，但不是文本框文本。我不确定是什么错？

Answer 1

您无法绑定到某个字段。你需要把它变成一个属性：

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

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

为您的其他课程做同样的事情。

WPF将文本框绑定到静态类的属性而不更新

1 个答案: