wpf mvvm prism案例

# **MvvmStudyDemo** ## Model(数据模型) View(视图) ViewModel(业务逻辑) ## **1.数据绑定,命名绑定** ```xaml <TextBlock x:Name="tb1" Text="{Binding MainModel.KeyWord}" /> <TextBox x:Name="tb2" Text=""/> <Button Content="搜索" Command="{Binding MainModel.BtnCommand}" CommandParameter="{Binding ElementName=tb2, Path=Text}"/> ``` ​ [Link](https://gitee.com/momj/wpf-mvvm-learning/tree/97f8e27d9440e9abd15ab420a3bb3ba30fb1b306/) ## 2.集合数据绑定,DataTemplate ```xaml <ItemsControl Height="200" ItemsSource="{Binding Datas}"> <!--数据模型 DataTemplate--> <ItemsControl.ItemTemplate> <DataTemplate> <StackPanel Orientation="Horizontal"> <TextBlock Text="{Binding}" Foreground="Orange"/> <TextBlock Text="{Binding KeyWord}" Foreground="Green"/> </StackPanel> </DataTemplate> </ItemsControl.ItemTemplate> </ItemsControl> ``` ## 3.集合命令绑定;ObservableCollection<**T>** 类: ```xaml <StackPanel> <!--从数据库查找相关关键词的数据 C# 数据源 绑定路径--> <TextBlock x:Name="tb1" Text="{Binding MainModel.KeyWord}" /> <TextBox x:Name="tb2" Text=""/> <Button Content="搜索" Command="{Binding MainModel.BtnCommand}" CommandParameter="{Binding ElementName=tb2, Path=Text}"/> <!--集合数据 ItemsControl ListView/ListBox/DataGrid Menu/ComboBox--> <ItemsControl Height="200" ItemsSource="{Binding Datas}"> <!--数据模型 DataTemplate--> <ItemsControl.ItemTemplate> <DataTemplate> <StackPanel Orientation="Horizontal"> <TextBlock Text="{Binding}" Foreground="Orange"/> <TextBlock Text="{Binding KeyWord}" Foreground="Green"/> <!--ViewModel中的数据属性--> <!--不要去找Border,实际使用中Border非常频繁--> <!--只写Banding,不写Path,表示当前的数据源/对象--> <Button Content="删除" Command="{Binding DataContext.BtnCommand, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Window}}" CommandParameter="{Binding}"/> </StackPanel> </DataTemplate> </ItemsControl.ItemTemplate> </ItemsControl> </StackPanel> ``` ```c# //TODO 集合控件的绑定对象 //若需要通知UI,不能是用List, //ObservableCollection<T> 类: //表示一个动态数据收集，该集合在添加或删除项或刷新整个列表时提供通知。 // //集合子项变动通知:增减 // 1.子项中的属性变化 KeyWord="New Value" 变化由通知来处理 INotifyPropertyChanged // 2.增加一个子项,或删除一个子项 变化由集合对象通知来处理 INotifyCollectionChanged public ObservableCollection<MainModel> Datas { get; set; } = new ObservableCollection<MainModel>(); ``` ## 3.拖动事件 ```xaml <Grid> <Grid.ColumnDefinitions> <ColumnDefinition/> <ColumnDefinition/> </Grid.ColumnDefinitions> <StackPanel> <Border Width="50" Height="50" Background="Orange" MouseLeftButtonDown="Border_MouseLeftButtonDown"/> </StackPanel> <Canvas Grid.Column="1" AllowDrop="True" Drop="Canvas_Drop" Background="Transparent"> </Canvas> </Grid> ``` Window后台cs代码 ```C# public partial class WindowDrag : Window { public WindowDrag() { InitializeComponent(); } private void Border_MouseLeftButtonDown(object sender, MouseButtonEventArgs e) { DragDrop.DoDragDrop(this, "Rectangle", DragDropEffects.Copy); } private void Canvas_Drop(object sender, DragEventArgs e) { string data = e.Data.GetData(typeof(string)).ToString(); if(data == "Rectangle") { Rectangle rectangle = new Rectangle() { Width =100, Height =100, Fill = Brushes.Red }; var point = e.GetPosition((IInputElement)sender); Canvas.SetLeft(rectangle, point.X); Canvas.SetTop(rectangle, point.Y); (sender as Canvas ).Children.Add(rectangle); } } } ``` ## 4.任意事件绑定,Command处理 **NuGet 引入 Microsoft.Xaml.Behaviors 类库 ** ```xaml xmlns:b="http://schemas.microsoft.com/xaml/behaviors" ``` Behaviors : 行为 使用XAML Behaviors for WPF，可以轻松地将互动性添加到您的应用程序中。行为封装了元素的可重复使用的功能，可以很容易地添加到你的XAML，而不需要更多的指令性代码。 **View** ```xaml <Grid> <Grid.ColumnDefinitions> <ColumnDefinition/> <ColumnDefinition/> </Grid.ColumnDefinitions> <StackPanel> <Border Width="50" Height="50" Background="Orange" MouseLeftButtonDown="Border_MouseLeftButtonDown"> </Border> <Border Width="50" Height="50" Background="Green"> <b:Interaction.Triggers> <b:EventTrigger EventName="MouseLeftButtonDown"> <b:InvokeCommandAction Command="{Binding MouseLeftCommand}" CommandParameter="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Border}}"/> </b:EventTrigger> </b:Interaction.Triggers> </Border> </StackPanel> <!--OLD <Canvas Grid.Column="1" AllowDrop="True" Drop="Canvas_Drop" Background="Transparent">--> <Canvas Grid.Column="1" AllowDrop="True" Background="Transparent" x:Name="canvas"> <b:Interaction.Triggers> <b:EventTrigger EventName="Drop"> <b:InvokeCommandAction Command="{Binding DropCommand}" PassEventArgsToCommand="True"/> </b:EventTrigger> <b:EventTrigger EventName="DragEnter"> <b:InvokeCommandAction Command="{Binding DragEnterCommand}" CommandParameter="{Binding ElementName=canvas}"/> </b:EventTrigger> </b:Interaction.Triggers> </Canvas> </Grid> ``` 1. 通过鼠标事件创建拖动对象 2. 通过Drop对象接收拖动对象,并且创建实际显示对象 **ViewModel** ```C# public class DragViewModel { public ICommand MouseLeftCommand { get; set; } public ICommand DropCommand { get; set; } public ICommand DragEnterCommand { get; set; } private Canvas _canvas; public DragViewModel() { MouseLeftCommand = new Command { DoExecute = obj => { DragDrop.DoDragDrop((DependencyObject)obj, "Rectangle", DragDropEffects.Copy); } }; DropCommand = new Command { DoExecute = obj => { //DragEventArgs var eventArgs = obj as DragEventArgs; string data = eventArgs.Data.GetData(typeof(string)).ToString(); if (data == "Rectangle") { Rectangle rectangle = new Rectangle() { Width = 100, Height = 100,