Question

我有一个带文本框的窗口。填写此表单有两个模板（两组数据）。用户单击单选按钮并选择模板。之后，文本框由模板中的数据填充。

<Window x:Class="WpfTestApplication.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" SizeToContent="Height" Width="500">
<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="35"></RowDefinition>
        <RowDefinition Height="35"></RowDefinition>
        <RowDefinition Height="35"></RowDefinition>
        <RowDefinition Height="35"></RowDefinition>
        <RowDefinition Height="35"></RowDefinition>
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="Auto"></ColumnDefinition>
        <ColumnDefinition Width="*"></ColumnDefinition>
    </Grid.ColumnDefinitions>

    <StackPanel Grid.Row="0" Grid.ColumnSpan="2" Orientation="Horizontal">
        <RadioButton GroupName="Templates" Content="Template1" IsChecked="True"></RadioButton>
        <RadioButton GroupName="Templates" Content="Template2"></RadioButton>
    </StackPanel>

    <Label Grid.Row="1" Grid.Column="0">Field1</Label>
    <TextBox Grid.Row="1" Grid.Column="1" Name="TbField1"></TextBox>

    <Label Grid.Row="2" Grid.Column="0">Field2</Label>
    <TextBox Grid.Row="2" Grid.Column="1" Name="TbField2"></TextBox>

    <Label Grid.Row="3" Grid.Column="0">Field3</Label>
    <TextBox Grid.Row="3" Grid.Column="1" Name="TbField3"></TextBox>

    <Button Grid.Row="4" Grid.ColumnSpan="2" Name="BtnGetData" Content="GetData" Click="BtnGetData_Click"></Button>
</Grid>

public partial class MainWindow : Window
{
    private static DataSetTest data1;
    private static DataSetTest data2;

    private static DataBingings bindings;

    public MainWindow()
    {
        InitializeComponent();

        data1 = new DataSetTest("field1_1", "field2_1", "field3_1");
        data2 = new DataSetTest("field1_2", "field2_2", "field3_2");

        bindings = new DataBingings();
        bindings.Add(TbField1, data1, "Field1", data2, "Field1");
        bindings.Add(TbField2, data1, "Field2", data2, "Field2");
        bindings.Add(TbField3, data1, "Field3", data2, "Field3");

        bindings.SetData();
    }

    private void BtnGetData_Click(object sender, RoutedEventArgs e)
    {
        bindings.GetData();
        MessageBox.Show(data1.Field1);
    }
}

public class DataSetTest
{
    public string Field1 { get; set; }
    public string Field2 { get; set; }
    public string Field3 { get; set; }

    public DataSetTest()
    {

    }

    public DataSetTest(string field1, string field2, string field3)
    {
        Field1 = field1;
        Field2 = field2;
        Field3 = field3;
    }
}

public class DataBingings
{
    List<BindingExpressionBase> bindings = new List<BindingExpressionBase>();

    private Binding AddBinding(string propertyName, object data)
    {
        Binding b = new Binding(propertyName);
        b.Mode = BindingMode.TwoWay;
        b.Source = data;
        b.ConverterCulture = CultureInfo.CurrentCulture;
        b.NotifyOnSourceUpdated = false;
        b.NotifyOnTargetUpdated = false;

        return b;
    }

    private MultiBinding AddMultiBinding(string propertyName1, object data1, object data2, string propertyName2)
    {
        MultiBinding mb = new MultiBinding();
        mb.Converter = new CustomMultiValueConvertor();
        mb.UpdateSourceTrigger = UpdateSourceTrigger.Explicit;

        Binding b = AddBinding(propertyName1, data1);
        mb.Bindings.Add(b);

        b = AddBinding(propertyName2, data2);
        mb.Bindings.Add(b);

        return mb;
    }

    public void Add(TextBox control, object data1, string propertyName1, object data2, string propertyName2)
    {
        MultiBinding b = AddMultiBinding(propertyName1, data1, data2, propertyName2);
        BindingExpressionBase be = BindingOperations.SetBinding(control, TextBox.TextProperty, b);
        bindings.Add(be);
    }

    public void SetData()
    {
        foreach (BindingExpressionBase b in bindings)
        {
            b.UpdateTarget();
        }
    }

    public void GetData()
    {
        foreach (BindingExpressionBase b in bindings)
        {
            b.UpdateSource();
        }
    }
}

public class CustomMultiValueConvertor : IMultiValueConverter
{
    public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
    {
        return values[0];
    }

    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
    {
        return value as object[];
    }
}

类DataBindings包含添加多重绑定和将数据插入文本框或从中获取数据的方法。但是，如何将参数从RadioButton发送到多重绑定以选择第一个或第二个绑定？

Answer 1

如果没有a good, minimal, complete code exampl，就无法知道什么是最适合您的方案的设计。您在这里没有提供太多上下文，这必然会限制我们对您的代码的了解。那说......

您可以设置MultiBinding.ConverterParameter属性;这将设置作为parameter和Convert()方法的ConvertBack()参数传递的值。

但请注意，你不能将它绑定到任何东西;它只能设置为某个特定值。因此，您必须根据您的无线电组的状态明确更新它。鉴于此，不考虑转换器或MultiBinding本身可能更有意义，只需根据单选按钮选择更新绑定本身。

也就是说，当单选按钮选择发生变化时，只需根据选择将 <{em> propertyName1或propertyName2绑定到所需的Text属性。< / p>

当然，可能有一种更好的，XAML声明的方式来做你想做的事情。同样，如果没有一个好的代码示例，那么推测这个特定点是不切实际的。如果上述内容看起来不像您真正想做的那样，请考虑改进问题，提供更好的代码示例，明确说明该代码示例的作用，以及它与您希望它做的不同。 / p>

多绑定选择参数

1 个答案: