Question

不好意思，我是菜鸟。我想单击按钮来更改文本块的背景颜色。变量的值可以更改，但是背景的颜色没有更改。有我的代码。请帮帮我。

Visual Studio 2017

WPF

TextBlock

<TextBlock Width="75" Height="75" HorizontalAlignment="Center" Margin="205,187,626,468" FontSize="48">
        <TextBlock.Style>
            <Style TargetType="TextBlock">

                <Setter Property="Text" Value="1" />
                <Setter Property="Background" Value="Red" />
                <Style.Triggers>
                    <DataTrigger Binding="{Binding Path=TestView,Mode=TwoWay}" Value="True">
                        <Setter Property="Text" Value="1" />
                        <Setter Property="Background" Value="Green" />
                    </DataTrigger>
                </Style.Triggers>
            </Style>
        </TextBlock.Style>
    </TextBlock>

和按钮

<Button Margin="202,596,564,0" VerticalAlignment="Top" Width="134" Click="buttonClick"> </Button>

Xaml.cs

private bool testView = true;
    public bool TestView
    {
        get { return testView; }
        set { testView = value; }
    }

    private void buttonClick(object sender, RoutedEventArgs e)
    {
        TestView = false;
    }

我希望当testView == true时，textblock的背景颜色为绿色；当testView == false时，textblock的背景颜色为Red。并且文本在TextBlock的中间

Answer 1

窗口（视图）未更新的原因是，您需要将更改通知给它。要在WPF中执行此操作，必须实现INotifyPropertyChanged接口，并相应地设置DataContext。通常，应使用MVVM设计模式完成此操作，但是为了回答您的问题，以下是使用当前设置进行操作的方法：

  public partial class Window1 : Window, INotifyPropertyChanged
    {
        private bool testView = true;
        public bool TestView
        {
            get { return testView; }
            set 
            { 
                if (testView != value)
                {
                    testView = value;
                    OnPropertyChanged("TestView");
                }
            }
        }

        public Window1()
        {
            InitializeComponent();
            DataContext = this;
        }

        private void buttonClick(object sender, RoutedEventArgs e)
        {
            TestView = false;
        }

        #region INotify
        public event PropertyChangedEventHandler PropertyChanged;

        protected void OnPropertyChanged(string propertyName)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }
        #endregion INotify
    }

WPF textblock背景色无法绑定变量

1 个答案: