WPF MVVM模式DataGrid1.构造MVVM基本功能类2.构造Model，ViewModel

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概述

1.构造MVVM基本功能类

因为没有使用MVVM框架，所以要自己构造两个MVVM的基本功能类，完成属性通知和命令绑定

1.1 属性通知


/// <summary>
/// INotifyPropertyChanged 用于通知属性改变（实现ViewModel向View喊话，所有绑定该属性的都会得到通知）
/// </summary>
public class NotificationObject : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
/// <summary>
/// 属性改变时调用该方法发出通知
/// </summary>
/// <param name="propertyName"></param>
public void RaisePropertyChanged(string propertyName)
{
if (this.PropertyChanged != null)
{
this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}

1.2 命令

public class DelegateCommand<T> : ICommand
{
private readonly Action<T> _executeMethod = null;
private readonly Func<T, bool> _canExecuteMethod = null;
public DelegateCommand(Action<T> executeMethod)
: this(executeMethod, null)
{ }
public DelegateCommand(Action<T> executeMethod, Func<T, bool> canExecuteMethod)
{
if (executeMethod == null)
throw new ArgumentNullException("executeMetnod");
_executeMethod = executeMethod;
_canExecuteMethod = canExecuteMethod;
}
#region ICommand 成员
/// <summary>
///
Method to determine if the command can be executed
/// </summary>
public bool CanExecute(T parameter)
{
if (_canExecuteMethod != null)
{
return _canExecuteMethod(parameter);
}
return true;
}
/// <summary>
///
Execution of the command
/// </summary>
public void Execute(T parameter)
{
if (_executeMethod != null)
{
_executeMethod(parameter);
}
}
#endregion
event EventHandler ICommand.CanExecuteChanged
{
add { CommandManager.RequerySuggested += value; }
remove { CommandManager.RequerySuggested -= value; }
}
#region ICommand 成员
public bool CanExecute(object parameter)
{
if (parameter == null && typeof(T).IsValueType)
{
return (_canExecuteMethod == null);
}
return CanExecute((T)parameter);
}
public void Execute(object parameter)
{
Execute((T)parameter);
}
#endregion
}

2.构造Model，ViewModel


public class Person
{
public int ID { get; set; }
public string Name { get; set; }
}

public class PersonModel : NotificationObject
{
private bool _IsSelected = false;
/// <summary>
/// 是否选中
/// </summary>
public bool IsSelected
{
get
{
return _IsSelected;
}
set
{
_IsSelected = value;
this.RaisePropertyChanged();
}
}
private Person _Person;
public Person Person
{
get
{
return _Person;
}
set
{
_Person = value;
this.RaisePropertyChanged();
}
}
}


public class PersonListViewModel : NotificationObject
{
public PersonListViewModel()
{
_Persons.Add(new PersonModel() { Person = new Person() { ID = 1, Name = "张三" } });
_Persons.Add(new PersonModel() { Person = new Person() { ID = 2, Name = "李四" } });
_Persons.Add(new PersonModel() { Person = new Person() { ID = 3, Name = "王五" } });
_Persons.Add(new PersonModel() { Person = new Person() { ID = 4, Name = "赵六" } });
_Persons.Add(new PersonModel() { Person = new Person() { ID = 5, Name = "刘七" } });
_Persons.Add(new PersonModel() { Person = new Person() { ID = 6, Name = "陈八" } });
}
private ObservableCollection<PersonModel> _Persons = new ObservableCollection<PersonModel>();
public ObservableCollection<PersonModel> Persons
{
get
{
return _Persons;
}
set
{
_Persons = value;
this.RaisePropertyChanged();
}
}
private bool _IsSelectAll = false;
public bool IsSelectAll
{
get { return _IsSelectAll; }
set
{
_IsSelectAll = value;
RaisePropertyChanged();
}
}
private ICommand _SelectAllCommand;
public ICommand SelectAllCommand
{
get
{
return _SelectAllCommand ?? (_SelectAllCommand = new DelegateCommand<object>(SelectAll));
}
}
/// <summary>
/// 全选
/// </summary>
/// <param name="id"></param>
public void SelectAll(object id)
{
foreach (var item in Persons)
{
item.IsSelected = IsSelectAll;
}
}
private ICommand _SelectCommand;
public ICommand SelectCommand
{
get
{
return _SelectCommand ?? (_SelectCommand = new DelegateCommand<int>(Select));
}
}
/// <summary>
/// 单选
/// </summary>
/// <param name="id"></param>
public void Select(int id)
{
PersonModel md = Persons.Where(p => p.Person.ID == id).FirstOrDefault();
if (md != null)
{
if (!md.IsSelected && IsSelectAll)
{
IsSelectAll = false;
}
else if (md.IsSelected && !IsSelectAll)
{
foreach (var item in Persons)
{
if (!item.IsSelected) return;
}
IsSelectAll = true;
}
}
}
/// <summary>
/// 判断是否选中
/// </summary>
/// <param name="onlyOne">是否单选</param>
/// <returns></returns>
public bool SelectValidate(bool onlyOne = false)
{
if (this.Persons.Count(p => p.IsSelected) < 1)
{
MessageBox.Show("未勾选数据！");
return false;
}
if (onlyOne)
{
if (this.Persons.Count(p => p.IsSelected) > 1)
{
MessageBox.Show("只能勾选一条数据！");
return false;
}
}
return true;
}
private ICommand _DelCommand;
public ICommand DelCommand
{
get
{
return _DelCommand ?? (_DelCommand = new DelegateCommand<object>(Del));
}
}
/// <summary>
/// 删除
/// </summary>
/// <param name="obj"></param>
public void Del(object obj = null)
{
if (!SelectValidate()) return;
MessageBoxResult result = MessageBox.Show("是否删除选中项?", "提示", MessageBoxButton.YesNo);
if (result != MessageBoxResult.Yes)
{
return;
}
StringBuilder sb = new StringBuilder();
bool hasSelect = false;
//获取选中的数据
foreach (var v in _Persons)
{
if (v.IsSelected) { sb.Append(v.Person.Name + ";"); hasSelect = true; }
}
if (!hasSelect)
{
MessageBox.Show("请选择修改项", "警告");
return;
}
MessageBox.Show("选中 " + sb.ToString());
}
private ICommand _EditCommand;
public ICommand EditCommand
{
get
{
return _EditCommand ?? (_EditCommand = new DelegateCommand<object>(Edit));
}
}
/// <summary>
/// 修改
/// </summary>
/// <param name="obj"></param>
public void Edit(object obj = null)
{
if (!SelectValidate(true)) return;
PersonModel model = null;
bool hasSelect = false;
//获取选中的数据
foreach (var v in _Persons)
{
if (v.IsSelected) { model = v; hasSelect = true; break; }
}
if (!hasSelect)
{
MessageBox.Show("请选择修改项", "警告");
return;
}
MessageBox.Show("选中 " + model.Person.Name);
}
}

<!--uc_PersonList.xaml-->
<!--需要将Checkbox的点击事件绑定到Command命令，引用System.Windows.Interactivity程序集可实现Event to Command功能，方式：引用 => 程序集 => 扩展 => System.Windows.Interactivity -->
<UserControl x:Class="MvvmDataGridCheckBoxSelectAll.uc_PersonList"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:MvvmDataGridCheckBoxSelectAll"
xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
mc:Ignorable="d">
<UserControl.DataContext>
<local:PersonListViewModel />
</UserControl.DataContext>
<DockPanel Margin="0">
<StackPanel DockPanel.Dock="Top" Orientation="Horizontal">
<Button Command="{Binding EditCommand}" ToolTip="修改">
<Button.Content>
<StackPanel Orientation="Horizontal" >
<Image Stretch="None" VerticalAlignment="Center" Source="../Images/List_Edit.png"/>
<TextBlock Text="修改" VerticalAlignment="Center"/>
</StackPanel>
</Button.Content>
</Button>
<Button Command="{Binding DelCommand}" ToolTip="删除">
<Button.Content>
<StackPanel Orientation="Horizontal" >
<Image Stretch="None" VerticalAlignment="Center" Source="../Images/List_Del.png"/>
<TextBlock Text="删除" VerticalAlignment="Center"/>
</StackPanel>
</Button.Content>
</Button>
<!--<Button Command="{Binding RefreshCommand}" ToolTip="刷新">
<Button.Content>
<StackPanel Orientation="Horizontal" >
<Image Stretch="None" VerticalAlignment="Center" Source="../Images/List_Refresh.png"/>
<TextBlock Text="刷新" VerticalAlignment="Center"/>
</StackPanel>
</Button.Content>
</Button>-->
</StackPanel>
<DataGrid x:Name="dataGrid" AutoGenerateColumns="False" GridLinesVisibility="None" CanUserAddRows="False" Focusable="False"
Margin="0" HorizontalAlignment="Left" VerticalAlignment="Top" ItemsSource="{Binding Persons}" Width="Auto" EnableColumnVirtualization="False">
<DataGrid.ColumnHeaderStyle>
<Style TargetType="DataGridColumnHeader">
<Setter Property="HorizontalContentAlignment" Value="Center">
</Setter>
</Style>
</DataGrid.ColumnHeaderStyle>
<DataGrid.Columns>
<DataGridTemplateColumn>
<DataGridTemplateColumn.Header>
<CheckBox IsChecked="{Binding DataContext.IsSelectAll,Mode=TwoWay, UpdateSourceTrigger=PropertyChanged,RelativeSource={RelativeSource AncestorType=UserControl, AncestorLevel=1 }}">
<i:Interaction.Triggers>
<i:EventTrigger EventName="Click">
<i:InvokeCommandAction Command="{Binding DataContext.SelectAllCommand ,RelativeSource={RelativeSource AncestorType=UserControl, AncestorLevel=1 }}" ></i:InvokeCommandAction>
</i:EventTrigger>
</i:Interaction.Triggers>
</CheckBox>
</DataGridTemplateColumn.Header>
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<CheckBox Margin="3" IsChecked="{Binding IsSelected,Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}">
<i:Interaction.Triggers>
<i:EventTrigger EventName="Click">
<i:InvokeCommandAction Command="{Binding DataContext.SelectCommand ,RelativeSource={RelativeSource AncestorType=UserControl, AncestorLevel=1 }}" CommandParameter="{Binding Person.ID}" ></i:InvokeCommandAction>
</i:EventTrigger>
</i:Interaction.Triggers>
</CheckBox>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
<DataGridTextColumn Binding="{Binding Person.Name}" Header="姓名" IsReadOnly="True" Width="*"></DataGridTextColumn>
</DataGrid.Columns>
</DataGrid>
</DockPanel>
</UserControl>