Question

因此，我有#profile=... #lgn=... aws --profile $profile logs get-log-events --log-stream-name $lsn --log-group-name /$lgn | jq --raw-output '.events[] | .message'个应用程序，其中有两个主窗口和两个WPF：

UserControls
HomeView.xaml

查看模型

OptionsView.xaml

申请开始时间

public class ApplicationViewModel : INotifyPropertyChanged
    {
        #region Fields

        private ICommand changePageCommand;
        private ICommand addFilesCommand;
        private IPageViewModel _currentPageViewModel;
        private List<IPageViewModel> _pageViewModels;
        #endregion

        public ApplicationViewModel()
        {
            // Add available pages
            PageViewModels.Add(new HomeViewModel() { IsSelected = true });
            PageViewModels.Add(new OptionsViewModel() { IsSelected = false });

            // Set starting page
            CurrentPageViewModel = PageViewModels[0];
        }

        #region Properties / Commands

        public ICommand ChangePageCommand
        {
            get
            {
                if (changePageCommand == null)
                {
                    changePageCommand = new RelayCommand(
                        p => ChangeViewModel((IPageViewModel)p),
                        p => p is IPageViewModel);
                }

                return changePageCommand;
            }
        }


        public List<IPageViewModel> PageViewModels
        {
            get
            {
                if (_pageViewModels == null)
                    _pageViewModels = new List<IPageViewModel>();
                return _pageViewModels;
            }
        }

        public IPageViewModel CurrentPageViewModel
        {
            get
            {
                return _currentPageViewModel;
            }
            set
            {
                if (_currentPageViewModel != value)
                {
                    _currentPageViewModel = value;
                    OnPropertyChanged("CurrentPageViewModel");
                }
            }
        }

        #endregion

        #region Methods

        private void ChangeViewModel(IPageViewModel viewModel)
        {
            if (!PageViewModels.Contains(viewModel))
                PageViewModels.Add(viewModel);
            CurrentPageViewModel = PageViewModels.FirstOrDefault(vm => vm == viewModel);
        }

        #endregion
    }

Windows重新启动

public partial class App : Application
    {
        protected override void OnStartup(StartupEventArgs e)
        {
            base.OnStartup(e);
            MainWindow app = new MainWindow();
            ApplicationViewModel context = new ApplicationViewModel();
            app.DataContext = context;
            app.Show();
        }
    }

在<Window.Resources> <DataTemplate DataType="{x:Type home:HomeViewModel}"> <home:HomeView /> </DataTemplate> <DataTemplate DataType="{x:Type options:OptionsViewModel}"> <options:OptionsView /> </DataTemplate> </Window.Resources>中，我有一个简单的HomeView.xaml：

button

我想添加一些简单的<Button Command="{Binding DataContext.AddFilesCommand, RelativeSource={RelativeSource AncestorType={x:Type Window}}}" CommandParameter="{Binding}"/>命令。

所以我尝试添加此Click：

ICommand

关于如何在每次public ICommand AddFilesCommand { }之后执行的命令上添加这种建议的任何建议？

Answer 1

这可以轻松得多。我将创建一个类来轻松实现命令：

using System;
using System.Windows.Input;

namespace YourNameSpace
{
    public class RelayCommand : ICommand
    {
        private Action Action;

        public Command(Action _action)
        {
            Action = _action;
        }

        public event EventHandler CanExecuteChanged = (sender, e) => { };

        public bool CanExecute(object parameter) => true;

        public void Execute(object parameter)
        {
            Action();
        }
    }
}

然后创建命令（您不需要专用的ICommand）：

public ICommand AddFileCommand { get; set; }

并使用它（在构造函数中）：

AddFileCommand = new RelayCommand(()=> 
{
    MethodToExecute();
});

XAML：

<Button Command="{Binding AddFileCommand}"/>

这样，您的代码将更易于查看。

WPF：实现MVVM按钮命令

1 个答案: