Question

我有以下代码：

窗口1：

<NVD3Chart
          id="barChart"
          type="multiBarChart"
          width={document.body.clientWidth-(document.body.clientWidth*0.13)}
          height={400}
          showLabel={false}
          stacked={true}
          showControls={true}
          showLegend={true}
          datum={this.state.activityOptions}
          color={['#3fceb1','#fff480']}
          x="label"
          y="values"
          reduceXTicks={false}
          tickFormat={d3.format('d')}/>

第二窗口：

        public MainWindow()
    {
        InitializeComponent();
    }

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        SecondWindow sndW = new SecondWindow(btnFirstWindow);
        sndW.Show();
    }


<Grid>
    <Button Name="btnFirstWindow" Content="Button" HorizontalAlignment="Left" Margin="317,166,0,0" VerticalAlignment="Top" Width="148" Height="70" Click="Button_Click"/>

</Grid>

如果我按下window1中的按钮，它应该从window2中的lblShowUser更改内容。从here得到了这个例子。但它不会起作用.. 两个窗口将打开，但内容不会改变。如果我将标签中的内容设置为＆＃34; test＆＃34;，它将无法更改为正确的时间，例如＆＃34;点击第一个窗口按钮：...＆＃34;

Answer 1

移动此代码 firstWindowButton.Click + = firstWindowButton_Click;

到SecondWindow构造函数。所以看起来应该是这样的：

    public SecondWindow(Button firstWindowButton) {
    this.firstWindowButton = firstWindowButton;
    firstWindowButton.Click += firstWindowButton_Click;
    InitializeComponent();
}

Answer 2

另一种方法是将两个窗口绑定到同一个ViewModel，并在 App.xaml 中将ViewModel定义为s StaticResource：

添加Command类和SharedViewModel类并定义所需的属性/命令：

public class Command : ICommand
{
    private readonly Action _action;
    public Command(Action action)
    {
        _action = action;
    }

    public event EventHandler CanExecuteChanged;
    public bool CanExecute(object parameter)
    {
        return true;
    }

    public void Execute(object parameter)
    {
        _action();
    }
}
public class SharedViewModel : INotifyPropertyChanged
{
    private string _labelText;
    public string LabelText
    {
        get { return _labelText; }
        set
        {
            _labelText = value;
            OnPropertyChanged();
        }
    }


    private ICommand _buttonClickCommand;
    public ICommand ButtonClickCommand => _buttonClickCommand ?? (_buttonClickCommand = new Command(ButtonClickAction));

    public void ButtonClickAction()
    {
        LabelText = "Updated Text";
    }

    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

在 App.xaml 中将SharedViewModel实例定义为StaticResource：

<Application.Resources>
<ResourceDictionary>
<local:SharedViewModel x:Key="SharedViewModel"/>
</ResourceDictionary>

窗口1：

Title="MainWindow" Height="450" Width="800" DataContext="{StaticResource SharedViewModel}">

<Grid>
    <Button Name="BtnFirstWindow" Content="Button" HorizontalAlignment="Left" Margin="317,166,0,0" VerticalAlignment="Top" Width="148" Height="70"  Command="{Binding ButtonClickCommand}"/>
</Grid>

窗口2

Title="Window2" Height="450" Width="800" DataContext="{StaticResource SharedViewModel}">
<Grid>
    <Label Name="lblShowUser" Content="{Binding LabelText}" HorizontalAlignment="Left" Margin="275,175,0,0" VerticalAlignment="Top" Height="92" Width="205"/>
</Grid>

在wpf中两个Windows之间进行更新

2 个答案: