WPF MVVMToolkit框架学习 命令的全局CanExecute

首先看效果

 实现方式也很简单，给ViewModel的PropertyChanged事件挂载命令的可否执行方法就行

Xaml代码

<Window
    x:Class="MVVMToolkit框架学习.Views.RegisterView"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:md="http://materialdesigninxaml.net/winfx/xaml/themes"
    xmlns:sys="clr-namespace:System;assembly=mscorlib"
    xmlns:vm="clr-namespace:MVVMToolkit框架学习.ViewModels"
    Title="RegisterView"
    Width="250"
    Height="300"
    d:DataContext="{d:DesignInstance Type={x:Type vm:RegisterVM}}"
    WindowStartupLocation="CenterScreen"
    mc:Ignorable="d">
    <Window.Resources>
        <ObjectDataProvider
            x:Key="GenderEnumTypes"
            MethodName="GetValues"
            ObjectType="{x:Type sys:Enum}">
            <ObjectDataProvider.MethodParameters>
                <x:Type TypeName="vm:EGender" />
            </ObjectDataProvider.MethodParameters>
        </ObjectDataProvider>
        <Style BasedOn="{StaticResource MaterialDesignTextBox}" TargetType="TextBox">
            <Setter Property="Margin" Value="5,0,0,20" />
            <Setter Property="MinWidth" Value="150" />
            <Setter Property="md:HintAssist.HelperTextFontSize" Value="10" />
        </Style>
    </Window.Resources>
    <Grid>
        <StackPanel
            HorizontalAlignment="Center"
            VerticalAlignment="Center"
            Orientation="Vertical">
            <StackPanel Orientation="Horizontal">
                <md:PackIcon VerticalAlignment="Center" Kind="Account" />
                <TextBox
                    md:HintAssist.HelperText="Input..."
                    md:HintAssist.Hint="Name"
                    md:TextFieldAssist.HasClearButton="True"
                    Text="{Binding Name, UpdateSourceTrigger=PropertyChanged}" Cursor="IBeam" />
            </StackPanel>
            <StackPanel Orientation="Horizontal">
                <md:PackIcon VerticalAlignment="Center" Kind="Phone" />
                <TextBox
                    md:HintAssist.HelperText="Input..."
                    md:HintAssist.Hint="Phone"
                    md:TextFieldAssist.HasClearButton="True"
                    Text="{Binding Phone, UpdateSourceTrigger=PropertyChanged}" />
            </StackPanel>
            <StackPanel Orientation="Horizontal">
                <md:PackIcon VerticalAlignment="Center" Kind="GenderMaleFemale" />
                <ComboBox
                    MinWidth="150"
                    Margin="5,0,0,20"
                    md:HintAssist.HelperText="Input..."
                    md:HintAssist.Hint="Gender"
                    md:TextFieldAssist.HasClearButton="True"
                    ItemsSource="{Binding Source={StaticResource GenderEnumTypes}}"
                    SelectedItem="{Binding Gender, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />
            </StackPanel>
            <Button
                Margin="20,20"
                Command="{Binding RegisterCmd}"
                Content="Register..." />
        </StackPanel>
    </Grid>
</Window>

cs代码

using Microsoft.Toolkit.Mvvm.ComponentModel;
using Microsoft.Toolkit.Mvvm.Input;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Input;

namespace MVVMToolkit框架学习.ViewModels
{
    public enum EGender
    {
        Women,

        Men,

        Other,
    }

    public class RegisterVM : ObservableValidator
    {
        private string _name;

        private EGender _gender;

        private string _phone;

        [Required(ErrorMessage = "名字是必须的！")]
        [StringLength(10, ErrorMessage = "名字长度不能超过10")]
        public string Name
        {
            get => _name;
            set => SetProperty(ref _name, value, true);
        }

        [Required(ErrorMessage = "电话号码是必须的！")]
        [Phone(ErrorMessage = "输入内容不是电话号码！")]
        public string Phone
        {
            get => _phone;
            set => SetProperty(ref _phone, value, true);
        }

        public EGender Gender
        {
            get => _gender;
            set => SetProperty(ref _gender, value, true);
        }

        public IRelayCommand RegisterCmd { get; set; }

        public RegisterVM()
        {
            PropertyChanged += (s, e) =>
            {
                //通知命令能否执行
                RegisterCmd?.NotifyCanExecuteChanged();
            };
            RegisterCmd = new RelayCommand(Register, () =>
            {
                //首先验证所有的属性
                ValidateAllProperties();
                return !HasErrors;
            });
        }

        private void Register()
        {
            MessageBox.Show("注册成功！");
        }
    }
}