C# WPF中数据网格中的条件CanUserAddRows_C#_Wpf_Xaml_Datagrid

C# WPF中数据网格中的条件CanUserAddRows

c# wpf xaml

C# WPF中数据网格中的条件CanUserAddRows,c#,wpf,xaml,datagrid,C#,Wpf,Xaml,Datagrid,假设我有一个组合框，如： <ComboBox SelectedValue="{Binding DataContext.CanUserAddMultipleRows, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Page}}, Converter={Static

假设我有一个组合框，如：

<ComboBox SelectedValue="{Binding DataContext.CanUserAddMultipleRows, 
                                  RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Page}},
                                 Converter={StaticResource yesNoToBooleanConverter}}">
    <ComboBoxItem>Yes</ComboBoxItem>
    <ComboBoxItem>No</ComboBoxItem>
</ComboBox>

现在我有了一个数据网格：

<DataGrid Grid.Row="7" Grid.Column="1" Grid.ColumnSpan="2" AutoGenerateColumns="False" 
          CanUserAddRows="{Binding DataContext.CanUserAddMultipleRows, 
                                   RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Page}}}"
          ItemsSource="{Binding DataContext.MyObject,
                                RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Page}}}">
    <DataGrid.Columns>
        <DataGridTextColumn Header="Quantity" Binding="{Binding Quantity}"></DataGridTextColumn>
        <DataGridTextColumn Header="Rate" Binding="{Binding Rate}"></DataGridTextColumn>
        <DataGridTextColumn Header="Amount" Binding="{Binding Amount}"></DataGridTextColumn>
    </DataGrid.Columns>
</DataGrid>

现在，我希望在默认情况下为用户提供1行，这样，如果CanUserAddRows=false，那么他们也应该能够向DataGrid添加1项。若CanUserAddRows=true，那个么用户可以拥有他想要的任意数量的行

这件事可能很简单，但我对DataGrid还不熟悉。所以，我问了这个问题。

在我的示例中，有一个bool类型的

MayUserAddRows

属性。如果

MayUserAddRows==true

则用户可以添加尽可能多的记录，但如果

MayUserAddRows==false

则他只能填充一条记录

还具有

CanUserAddRows

属性，该属性直接与

DataGrid.CanUserAddRows

的属性绑定

ViewModel中的属性通过NotificationObject实现接口。他有一个事件

propertychangedventhandler（propertyName）

，通知通知属性。关键逻辑如下：

private void MyViewModel_PropertyChanged(object sender, PropertyChangedEventArgs e)
{
    if (e.PropertyName.Equals("MayUserAddRows")) 
    {
        // The MayUserAddRows property is changed
        if (MyViewModel.MayUserAddRows == true) 
        {
            // Allow to add a lot of records
            MyViewModel.CanUserAddRows = true;
        }

        if (MyViewModel.MayUserAddRows == false)
        {
            // Prohibit the addition 
            MyViewModel.CanUserAddRows = false;

            // And add the empty row
            AddEmptyRow(MyViewModel.MyCollection);
        }                
    }
}

下面是一个完整的示例：

XAML

<Window x:Class="ConditionalCanUserAddRows.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:this="clr-namespace:ConditionalCanUserAddRows"
        WindowStartupLocation="CenterScreen"
        Title="MainWindow" Height="300" Width="325">

    <Grid>
        <CheckBox Content="{Binding Path=IsChecked,
                                    RelativeSource={RelativeSource Mode=Self}}"
                  ContentStringFormat="May user add rows - {0}"
                  HorizontalAlignment="Left"
                  VerticalAlignment="Top"
                  IsChecked="{Binding Path=MayUserAddRows}" />

        <Button Content="Clear" 
                VerticalAlignment="Top"
                HorizontalAlignment="Right"
                Click="Clear_Click" />

        <DataGrid Name="SimpleDataGrid"
                  Width="200"
                  Height="200"
                  CanUserResizeColumns="False"                  
                  AutoGenerateColumns="False" 
                  RowHeaderWidth="0" 
                  CanUserAddRows="{Binding Path=CanUserAddRows, Mode=TwoWay}"
                  ItemsSource="{Binding Path=MyCollection}">

            <DataGrid.Columns>
                <DataGridTextColumn Width="1.5*"
                                    Header="Name"
                                    Binding="{Binding Path=Name}" />

                <DataGridTextColumn Header="Age"                                    
                                    Width="1.5*" 
                                    FontSize="14" 
                                    Binding="{Binding Path=Age}" />
            </DataGrid.Columns>
        </DataGrid>
    </Grid>
</Window>

public partial class MainWindow : Window
{   
    ViewModel MyViewModel = new ViewModel();

    public MainWindow()
    {
        InitializeComponent();

        this.DataContext = MyViewModel;

        MyViewModel.MyCollection = new ObservableCollection<Person>();

        MyViewModel.MyCollection.Add(new Person()
        {
            Age = 22,
            Name = "Nick",
        });

        MyViewModel.MyCollection.Add(new Person()
        {
            Age = 11,
            Name = "Sam",
        });

        MyViewModel.MyCollection.Add(new Person()
        {
            Name = "Kate",
            Age = 15,
        });

        AddEmptyRow(MyViewModel.MyCollection);

        MyViewModel.PropertyChanged += new PropertyChangedEventHandler(MyViewModel_PropertyChanged);
    }

    private void MyViewModel_PropertyChanged(object sender, PropertyChangedEventArgs e)
    {
        if (e.PropertyName.Equals("MayUserAddRows"))
        {
            if (MyViewModel.MayUserAddRows == true) 
            {
                MyViewModel.CanUserAddRows = true;
            }

            if (MyViewModel.MayUserAddRows == false)
            {
                MyViewModel.CanUserAddRows = false;
                AddEmptyRow(MyViewModel.MyCollection);
            }                
        }
    }

    #region AddEmptyRow

    private void AddEmptyRow(ObservableCollection<Person> collection) 
    {
        collection.Add(new Person()
        {
            Name = "",
            Age = 0,
        });
    }

    #endregion

    #region Clear

    private void Clear_Click(object sender, RoutedEventArgs e)
    {
        MyViewModel.MyCollection.Clear();
    }

    #endregion
}

#region ViewModel

public class ViewModel : NotificationObject
{
    #region MyCollection

    public ObservableCollection<Person> MyCollection
    {
        get;
        set;
    }

    #endregion

    #region CanUserAddRows

    private bool _canUserAddRows = false;

    public bool CanUserAddRows
    {
        get
        {
            return _canUserAddRows;
        }

        set
        {
            _canUserAddRows = value;
            NotifyPropertyChanged("CanUserAddRows");
        }
    }

    #endregion

    #region MayUserAddRows

    private bool _mayUserAddRows = false;

    public bool MayUserAddRows
    {
        get
        {
            return _mayUserAddRows;
        }

        set
        {
            _mayUserAddRows = value;
            NotifyPropertyChanged("MayUserAddRows");
        }
    }

    #endregion
}

#endregion

#region Model

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

    public int Age
    {
        get;
        set;
    }
}

#endregion

#region NotificationObject

public class NotificationObject : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    protected void NotifyPropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

#endregion

输出

<Window x:Class="ConditionalCanUserAddRows.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:this="clr-namespace:ConditionalCanUserAddRows"
        WindowStartupLocation="CenterScreen"
        Title="MainWindow" Height="300" Width="325">

    <Grid>
        <CheckBox Content="{Binding Path=IsChecked,
                                    RelativeSource={RelativeSource Mode=Self}}"
                  ContentStringFormat="May user add rows - {0}"
                  HorizontalAlignment="Left"
                  VerticalAlignment="Top"
                  IsChecked="{Binding Path=MayUserAddRows}" />

        <Button Content="Clear" 
                VerticalAlignment="Top"
                HorizontalAlignment="Right"
                Click="Clear_Click" />

        <DataGrid Name="SimpleDataGrid"
                  Width="200"
                  Height="200"
                  CanUserResizeColumns="False"                  
                  AutoGenerateColumns="False" 
                  RowHeaderWidth="0" 
                  CanUserAddRows="{Binding Path=CanUserAddRows, Mode=TwoWay}"
                  ItemsSource="{Binding Path=MyCollection}">

            <DataGrid.Columns>
                <DataGridTextColumn Width="1.5*"
                                    Header="Name"
                                    Binding="{Binding Path=Name}" />

                <DataGridTextColumn Header="Age"                                    
                                    Width="1.5*" 
                                    FontSize="14" 
                                    Binding="{Binding Path=Age}" />
            </DataGrid.Columns>
        </DataGrid>
    </Grid>
</Window>

public partial class MainWindow : Window
{   
    ViewModel MyViewModel = new ViewModel();

    public MainWindow()
    {
        InitializeComponent();

        this.DataContext = MyViewModel;

        MyViewModel.MyCollection = new ObservableCollection<Person>();

        MyViewModel.MyCollection.Add(new Person()
        {
            Age = 22,
            Name = "Nick",
        });

        MyViewModel.MyCollection.Add(new Person()
        {
            Age = 11,
            Name = "Sam",
        });

        MyViewModel.MyCollection.Add(new Person()
        {
            Name = "Kate",
            Age = 15,
        });

        AddEmptyRow(MyViewModel.MyCollection);

        MyViewModel.PropertyChanged += new PropertyChangedEventHandler(MyViewModel_PropertyChanged);
    }

    private void MyViewModel_PropertyChanged(object sender, PropertyChangedEventArgs e)
    {
        if (e.PropertyName.Equals("MayUserAddRows"))
        {
            if (MyViewModel.MayUserAddRows == true) 
            {
                MyViewModel.CanUserAddRows = true;
            }

            if (MyViewModel.MayUserAddRows == false)
            {
                MyViewModel.CanUserAddRows = false;
                AddEmptyRow(MyViewModel.MyCollection);
            }                
        }
    }

    #region AddEmptyRow

    private void AddEmptyRow(ObservableCollection<Person> collection) 
    {
        collection.Add(new Person()
        {
            Name = "",
            Age = 0,
        });
    }

    #endregion

    #region Clear

    private void Clear_Click(object sender, RoutedEventArgs e)
    {
        MyViewModel.MyCollection.Clear();
    }

    #endregion
}

#region ViewModel

public class ViewModel : NotificationObject
{
    #region MyCollection

    public ObservableCollection<Person> MyCollection
    {
        get;
        set;
    }

    #endregion

    #region CanUserAddRows

    private bool _canUserAddRows = false;

    public bool CanUserAddRows
    {
        get
        {
            return _canUserAddRows;
        }

        set
        {
            _canUserAddRows = value;
            NotifyPropertyChanged("CanUserAddRows");
        }
    }

    #endregion

    #region MayUserAddRows

    private bool _mayUserAddRows = false;

    public bool MayUserAddRows
    {
        get
        {
            return _mayUserAddRows;
        }

        set
        {
            _mayUserAddRows = value;
            NotifyPropertyChanged("MayUserAddRows");
        }
    }

    #endregion
}

#endregion

#region Model

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

    public int Age
    {
        get;
        set;
    }
}

#endregion

#region NotificationObject

public class NotificationObject : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    protected void NotifyPropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

#endregion

MayUserAddRows=“False”

MayUserAddRows=“True”

在VisualStudio2010下编译的项目，这个例子完全符合MVVM风格

此项目可用

回答得好！谢谢我想再增加3个功能。1）用户点击清除按钮。然后他选中复选框，此时添加了两行。1具有默认值，另一个为空。当时，我不希望用户有一行带有默认值。2）当用户取消选中该复选框时，我想清除所有行以及“年龄单元格”列应包含所有年龄的总和。例如，在您答案的最后一张图片中，如果我取消选中复选框，则只有一行应该在那里，并且年龄应该包含1491（因为22+11+15+666+777=1491）。3）我还希望有一个只有两个值的新DataGridComboBoxColumn。i、 e.1）继续2）列表结束。如果用户选择“继续”，则他应该能够在当前行中添加姓名和年龄等详细信息，并且应该能够在填写当前行的详细信息后添加新行。否则，不应允许他在当前行中填写更多详细信息，如姓名和年龄，并且不应在该行之后创建新行。@Vishal:这就是我必须实现的全部功能？对不起，我只做了有问题的事，你自己能做的一切。此外，你必须先在问题中写出来。