MVVMLight Command 绑定示例

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/BYH371256/article/details/89225269

本章讲述：在MVVMLight中，简单的Command命令绑定示例；

前端代码示例：两种绑定方式

xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"    <!--引用库-->

<Window.DataContext>
        <vm:MainWindowVM/>
    </Window.DataContext>
    <StackPanel HorizontalAlignment="Left">
        <Button Margin="10" Width="100" Height="30" Content="MVVM1" Command="{Binding ShowMsgCommand}"></Button>
        <Button Margin="10" Width="100" Height="30" Content="MVVM2" Command="{Binding ButtonClickCommand}"></Button>
        <Button Margin="10" Width="100" Height="30" Content="MVVM2" Command="{Binding CloseCmd}"
                CommandParameter="{Binding RelativeSource={x:Static RelativeSource.Self}}"/>
<Button Style="{StaticResource ViewImagebtnStyleKey}" Margin="5 0 0 0" ToolTip="" Command="{Binding DelCommand,RelativeSource={RelativeSource TemplatedParent}}" CommandParameter="{Binding}">
	<Image  Height="20" Width="20"  Source="/DSViewer;component/Images/ImageList/delete.png" Stretch="Fill"/>
</Button>


        <Button Name="btn" Content="Button" Height="30" HorizontalAlignment="Left" Margin="10" VerticalAlignment="Top" Width="100">
            <i:Interaction.Triggers>
                <i:EventTrigger EventName="Click">
                    <i:InvokeCommandAction Command="{Binding Command1}" CommandParameter="10" />
                </i:EventTrigger>
                <i:EventTrigger EventName="MouseMove">
                    <i:InvokeCommandAction Command="{Binding Command2}" CommandParameter="{Binding ElementName=btn}" />
                </i:EventTrigger>
                <i:EventTrigger EventName="MouseLeave">
                    <i:InvokeCommandAction Command="{Binding Command_MousLeave}" CommandParameter="{Binding ElementName=btn}"/>
                </i:EventTrigger>
            </i:Interaction.Triggers>
        </Button>

        <Image Name="imge" Width="25" Height="25" HorizontalAlignment="Center" Margin="10" Source="/CommandTest;component/Images/u1285.png">
            <i:Interaction.Triggers>
                <i:EventTrigger EventName="MouseEnter">
                    <i:InvokeCommandAction Command="{Binding Command_MouseEnter}" CommandParameter="{Binding ElementName=imge}"/>
                </i:EventTrigger>
                <i:EventTrigger EventName="MouseLeave">
                    <i:InvokeCommandAction Command="{Binding Command_ImageMouseLeave}" CommandParameter="{Binding ElementName=imge}"/>
                </i:EventTrigger>
                <i:EventTrigger EventName="MouseLeftButtonUp">
                    <i:InvokeCommandAction Command="{Binding Command_Click}" CommandParameter="{Binding ElementName=imge}"/>
                </i:EventTrigger>
            </i:Interaction.Triggers>
            
        </Image>
    </StackPanel>

“CommandParameter="{Binding RelativeSource={x:Static RelativeSource.Self}}" ”表示：绑定的参数是自身；

“CommandParameter="{Binding ElementName=btn}" ”  表示：绑定一个控件，btn是控件名称；

“CommandParameter="10"  ” 表示：绑定参数是10；

后端逻辑代码

        private ICommand m_CloseCmd;
        public ICommand CloseCmd
        {
            get
            {
                return m_CloseCmd ?? (m_CloseCmd = new RelayCommand<Button>((bnt) =>
                {
                    bnt.Content = "Close";
                    MessageBox.Show("Close Window!");
                    App.Current.MainWindow.Close();
                }));
            }
        }

        private ICommand m_Command1;
        public ICommand Command1
        {
            get
            {
                return m_Command1 ?? (m_Command1 = new RelayCommand<string>((str) =>
                {
                    string param = str;
                    MessageBox.Show("参数 ：" + param);
                }));
            }
        }

        private ICommand m_Command2;
        public ICommand Command2
        {
            get
            {
                return m_Command2 ?? (m_Command2 = new RelayCommand<Button>((btn) =>
                {
                    btn.Content = "setting";
                }));
            }
        }

        private ICommand m_Command_MousLeave;
        public ICommand Command_MousLeave
        {
            get
            {
                return m_Command_MousLeave ?? (m_Command_MousLeave = new RelayCommand<Button>((bnt) =>
                    {
                        bnt.Content = "Button";
                    }));
            }
        }


        private ICommand m_Command_MouseEnter;
        public ICommand Command_MouseEnter
        {
            get
            {
                return m_Command_MouseEnter ?? (m_Command_MouseEnter = new RelayCommand<Image>((img) =>
                    {
                        img.Source = BitmapFromUri(new Uri("pack://application:,,,/CommandTest;component/Images/u1128.png"));
                    }));
            }
        }

        private ICommand m_Command_ImageMouseLeave;
        public ICommand Command_ImageMouseLeave
        {
            get
            {
                return m_Command_ImageMouseLeave ?? (m_Command_ImageMouseLeave = new RelayCommand<Image>((img) =>
                    {
                        img.Source = BitmapFromUri(new Uri("pack://application:,,,/CommandTest;component/Images/u1285.png"));
                    }));
            }
        }

        private ICommand m_Command_Click;
        public ICommand Command_Click
        {
            get
            {
                return m_Command_Click ?? (m_Command_Click = new RelayCommand<Image>((img) =>
                    {
                        MessageBox.Show("Image click!");
                    }));
            }
        }

        static object lockObj = new object();
        public static System.Windows.Media.ImageSource BitmapFromUri(Uri source)
        {
            var bitmap = new System.Windows.Media.Imaging.BitmapImage();
            try
            {
                var temp = new System.Windows.Media.Imaging.BitmapImage(source);
                temp = null;
                lock (lockObj)
                {
                    bitmap.BeginInit();
                    bitmap.UriSource = source;
                    bitmap.CacheOption = System.Windows.Media.Imaging.BitmapCacheOption.OnLoad;
                    bitmap.EndInit();
                }
            }
            catch { }
            return bitmap;
        }