WPF设计标准学习记录21

xmlns:i="http://schemas.microsoft.com/xaml/behaviors"

<TextBox x:Name="textbox" Grid.Row="1" Margin="5" TextWrapping="Wrap">
    <i:Interaction.Triggers>
        <i:EventTrigger EventName="PreviewMouseDown">
            <i:InvokeCommandAction Command="{Binding MouseDownCommand}"
                                   CommandParameter="{Binding RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=TextBox}}">
            </i:InvokeCommandAction>
        </i:EventTrigger>
    </i:Interaction.Triggers>
</TextBox>

graph TD 
    A[TextBox] --> B[属性]
    A --> C[子元素: Interaction.Triggers]
    
    B --> B1[Name=textbox]
    B --> B2[Grid.Row=1]
    B --> B3[Margin=5]
    B --> B4[TextWrapping=Wrap]
    
    C --> C1[EventTrigger]
    C1 --> C1a[EventName=PreviewMouseDown]
    C1 --> C1b[InvokeCommandAction]
    
    C1b --> C1b1[Command绑定]
    C1b1 --> VM[ViewModel.MouseDownCommand]
    
    C1b --> C1b2[CommandParameter]
    C1b2 --> Self[TextBox自身引用]

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace wpfrunrun
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            //MessageBox.Show("HelloWorld");
        }

        private void CommandBinding_Executed(object sender, ExecutedRoutedEventArgs e)
        {
            MessageBox.Show("我是ALT+S");
        }

        private void CommandBinding_CanExecute(object sender, CanExecuteRoutedEventArgs e)
        {
            e.CanExecute = true;
        }

       
        private void OpenCommandCanExecute(object sender, CanExecuteRoutedEventArgs e)
        {
            e.CanExecute = true;
        }

        private void OpenCommandExecuted(object sender, ExecutedRoutedEventArgs e)
        {
            var openFileDialog = new Microsoft.Win32.OpenFileDialog()
            {
                Filter = "文本文档(.txt)|*.txt",
                Multiselect = true,
            };
            var result = openFileDialog.ShowDialog();
            if(result.Value)
            {
                txtBox.Text = File.ReadAllText(openFileDialog.FileName);
            }
        }

        private void CutCommandCanExecute(object sender, CanExecuteRoutedEventArgs e)
        {
            e.CanExecute = txtBox != null && txtBox.SelectionLength > 0;
        }

        private void CutCommandExecuted(object sender, ExecutedRoutedEventArgs e)
        {
            txtBox.Cut();
        }

        private void PasteCommandCanExecute(object sender, CanExecuteRoutedEventArgs e)
        {
            e.CanExecute = Clipboard.ContainsImage();
        }

        private void PasteCommandExecuted(object sender, ExecutedRoutedEventArgs e)
        {
            txtBox.Paste();
        }

        private void SaveCommandCanExecute(object sender, CanExecuteRoutedEventArgs e)
        {
            e.CanExecute = txtBox != null && txtBox.Text.Length > 0;
        }

        private void SaveCommandExecuted(object sender, ExecutedRoutedEventArgs e)
        {
            var saveFileDialog = new Microsoft.Win32.SaveFileDialog()
            {
                Filter = "文本文档(.txt)|*.txt"
            };
            if(saveFileDialog.ShowDialog() == true)
            {
                File.WriteAllText(saveFileDialog.FileName, txtBox.Text);
            }
        }





    }

    //public class RelayCommand : ICommand
    //{
    //    private Action action;
    //    public RelayCommand(Action action)
    //    {
    //        this.action = action;
    //    }

    //    public event EventHandler CanExecuteChanged;

    //    public bool CanExecute(object parameter)
    //    {
    //        return true;
    //    }

    //    public void Execute(object parameter)
    //    {
    //        action?.Invoke(); 
    //    }
    //}


    public class RelayCommand : ICommand
    {
        private Action action;
        private Action<object> objectAction;
        public RelayCommand(Action action)
        {
            this.action = action;
        }
        public RelayCommand(Action<object> objectAction)
        {
            this.objectAction = objectAction;
        }
        public event EventHandler CanExecuteChanged;

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

        public void Execute(object parameter)
        {
            action?.Invoke();
            objectAction?.Invoke(parameter);
        }

    }




    public class MainViewModel : ObservableObject
    {
        public RelayCommand OpenCommand { get; set; } = new RelayCommand(() =>
        {
            MessageBox.Show("HelloWorld");
        });

        public RelayCommand OpenParamCommand { get; set; } = new RelayCommand((param) =>
        {
            MessageBox.Show(param.ToString());
        });


        public RelayCommand OpenTParamCommand { get; set; } = new RelayCommand ((t) =>
        {
            MessageBox.Show(t.ToString());
        });

        public RelayCommand<TextBox> MouseDownCommand { get; set; } = new RelayCommand<TextBox>((txtBox) =>
        {
            txtBox.Text += DateTime.Now + "宁点击泪" + "\r";
        });



    }

    public class RelayCommand<T> : ICommand
    {
        public RelayCommand(Action<T> action)
        {
            Action = action;
        }

        public event EventHandler CanExecuteChanged;

        public Action<T> Action { get; }
        public Action<object> Value { get; }

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

        public void Execute(object parameter)
        {
            Action?.Invoke((T)parameter);
        }
    }


    public class ObservableObject : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;

        public void RaisePropertyChanged([CallerMemberName] string propertyName = "")
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}