Question

我是WPF技术的新手。我正在使用MVVM架构。我想根据viewmodel的属性更改textblock的背景。例如，如果我使用'brush'对象，我想将它绑定到textblock的背景颜色。

<TextBlock Margin="0,1"
                    HorizontalAlignment="Center"
                    FontFamily="Arial"
                    FontSize="16"
                    Text="{Binding Line}"
                    TextWrapping="Wrap"
                    Background="{Binding brushobj}"/>

如何实施？

Answer 1

您可以在ViewModel中定义它。

private Brush _brushobj;
/// <summary>
/// Gets or sets the BrushObject.
/// </summary>
public Brush BrushObj
{
    get
    {
        return _brushobj;
    }
    set
    {

        // Set value
        _brushobj = value;

        // Notify UI that the value has changed.
        RaisePropertyChanged("BrushObj");
        // OnPropertyChanged("BrushObj"); // Use the appropriate function to notify the UI.
    }
}

然后只需使用以下内容设置值：

BrushObj = (Brush)new BrushConverter().ConvertFromString("Green");

最后，您将其绑定到View，就像在问题中所做的那样：

Background="{Binding BrushObj}"

编辑：我试图自己创建一个项目只是为了验证这确实有效，并且以下代码工作正常。如果它仍然不能正常工作，那么更有可能是你的MVVM设置导致问题。

<强> MainWindowViewModel：

namespace WpfApplication1
{
        public class MainWindowViewModel : ObservableObject
        {
           private Brush _brushobj = (Brush)new BrushConverter().ConvertFromString("Red");
           public Brush BrushObj
           {
                get
                {
                     return _brushobj;
                }
                set
                {
                     _brushobj = value; // Set value
                     RaisePropertyChanged("BrushObj"); // Notify UI that the value has changed.
                }
           }
      }
}

<强>主窗口：

    <Window x:Class="WpfApplication1.MainWindow"
            xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
            xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
            Title="MainWindow" Height="350" Width="525">
        <Grid>
            <TextBlock Margin="0,1"
                        VerticalAlignment="Center"
                        HorizontalAlignment="Center"
                        FontFamily="Arial"
                        FontSize="16"
                        Text="Testing a lot of stuff here! important stuff!"
                        TextWrapping="Wrap"
                        Background="{Binding BrushObj}"/>
        </Grid>
    </Window>

如何更改MVVM-WPF中文本块的背景颜色

1 个答案: