c# - 如何在wpf中单击按钮更新文本框背景色

Question

我有两个文本框，其中包含 rollnumber 和 name 并且包含在 ListBox 中。我有一个按钮，每次点击都会在文本框中添加数据。

我想要实现的是，当我单击按钮时，它必须将两个文本框的背景颜色更改为绿色。 (请记住，每次单击此按钮时，我都会有一个新行，它会在两个文本框中添加一些文本)。

我尝试使用触发器，但还不能成功。代码如下:

 <Window.Resources>
        <Style x:Key="buttonColorChange" TargetType="{x:Type Button}">
            <Style.Triggers>
                <DataTrigger Binding="{Binding Click, ElementName=btnClick}" Value="true">
                    <Setter Property="Background" Value="Green"></Setter>
                </DataTrigger>                
            </Style.Triggers>
        </Style>
    </Window.Resources>
    <Grid>

        <ListBox Name="empLB" ItemsSource="{Binding Path=emp}" Height="100" Width="300" VerticalAlignment="Top">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <DockPanel  Width="300" >                        
                        <TextBox  Name="txt2" Text="{Binding Path= RollNo}"></TextBox>
                        <TextBox  Name="txt1" Text="{Binding Path=Name}"></TextBox>
                    </DockPanel>
                </DataTemplate>
            </ListBox.ItemTemplate>            
        </ListBox>
        <Button  Style="{StaticResource buttonColorChange}" Name="btnClick" Height="20" Width="100" Content="click On me" Command="{Binding BtnClick}" ></Button>
    </Grid>

如何将点击按钮时的文本框颜色更改为绿色？

Answer 1

像评论者一样，我也会将该逻辑放入 ViewModel。这是一个例子。我正在使用 GalaSoft.MvvmLight nuget 包。

查看 XAML:

<Window.Resources>
    <local:BoolToBrushConverter x:Key="boolToColorConv" />
</Window.Resources>
<Grid>
    <ListBox Name="empLB" ItemsSource="{Binding Path=emp}" Height="100" Width="300" VerticalAlignment="Top">
        <ListBox.ItemTemplate>
            <DataTemplate>
                <DockPanel  Width="300" >
                    <TextBox  Name="txt2" 
                              Text="{Binding Path= RollNo}" 
                              Background="{Binding  Path=DataContext.ContainsItems, 
                                                    Converter={StaticResource boolToColorConv}, 
                                                    RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Grid}} }" />
                    <TextBox  Name="txt1" 
                              Text="{Binding Path=Name}" 
                              Background="{Binding  Path=DataContext.ContainsItems, 
                                                    Converter={StaticResource boolToColorConv}, 
                                                    RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Grid}} }" />
                </DockPanel>
            </DataTemplate>
        </ListBox.ItemTemplate>
    </ListBox>
    <Button Name="btnClick" Height="20" Width="100" Content="click On me" Command="{Binding BtnClick}" />
</Grid>

查看代码:

public partial class RollWindow : Window
{
    public RollWindow()
    {
        InitializeComponent();
    }

    private void Window_Loaded(object sender, RoutedEventArgs e)
    {
        // You might want to replace this with a ViewModel locator
        DataContext = new RollsViewModel();
    }
}

View 模型:

public class RollsViewModel : ViewModelBase
{
    public ObservableCollection<Item> emp
    {
        get;
        set;
    }

    public bool ContainsItems
    {
        get { return _containsItems; }
        set { _containsItems = value; RaisePropertyChanged(); }
    }
    private bool _containsItems;

    public RollsViewModel()
    {
        emp = new ObservableCollection<Item>();
    }

    public ICommand BtnClick
    {
        get
        {               
            if (_btnClick == null)
            {
                _btnClick = new RelayCommand(() =>
                {
                    // Dummy action, replace with call to model
                    emp.Add(new Item() { Name = "A roll", RollNo = emp.Count });
                    ContainsItems = emp.Count > 0;
                });
            }
            return _btnClick;
        }
    }
    private RelayCommand _btnClick;       
}

public class Item : ViewModelBase
{
    public int RollNo
    {
        get { return _rollNo; }
        set { _rollNo = value; RaisePropertyChanged();  }
    }
    private int _rollNo;

    public string Name
    {
        get { return _name; }
        set { _name = value; RaisePropertyChanged(); }
    }
    private string _name;
}

转换器:

public class BoolToBrushConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        var color = (value is bool && (bool)value) ? System.Windows.Media.Colors.Green : System.Windows.SystemColors.ControlColor;
        return new SolidColorBrush(color);
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}