如何绑定DataGrid在我的情况下使用mvvm (ObservableCollection内部ObservableCo

本文关键字:mvvm 内部 ObservableCo 情况下 ObservableCollection 何绑定 绑定 DataGrid 我的 | 更新日期: 2023-09-27 18:14:00

我在这种情况下,我有ObservableCollection的"tablegenerateModel"类进一步包含ObservableCollection的"column_Data"类,这个"column_Data"类包含3个UI元素必须绑定到包含三列的DataGrid。你可以复制粘贴我的代码,如果你想,我已经写了所有的类和xaml为您验证我的代码所以我的Model.cs如下所示:

  public class tablegenerateModel {
    public ObservableCollection < column_Data > Column_data_List {
        get;
        set;
    }
    public int NumberOfColumns {
        get;
        set;
    }
    private ICommand _CreatColumnCommand; //THIS IS THE BUTTON EVENT GENERATED WHEN USER PRESS AN INTEGER VALUE IN "NumberOfColumns" AND PRESS "Create" button. So the "Column_data_List" will repeat that many times the value user entered
    ViewModel vm;
    public ICommand CreatColumnCommand {
        get {
            if (_CreatColumnCommand == null) {
                _CreatColumnCommand = new RelayCommand(
                    param => vm = new ViewModel(this)
                );
            }
            return _CreatColumnCommand;
        }
    }
}
public class column_Data {
    public string Column_Name {
        get;
        set;
    }
}

My View Model is:

   public class ViewModel: INotifyPropertyChanged {
    private ObservableCollection < tablegenerateModel > _lb_GlobalList;
    private ObservableCollection < column_Data > _Column_data_List;
    public ObservableCollection < tablegenerateModel > lb_GlobalList {
        get {
            return _lb_GlobalList;
        }
        set {
            if (value != _lb_GlobalList) {
                _lb_GlobalList = value;
                RaisePropertyChanged("lb_GlobalList");
            }
        }
    }
    public ObservableCollection < column_Data > Column_data_List {
        get {
            return _Column_data_List;
        }
        set {
            if (value != _Column_data_List) {
                _Column_data_List = value;
                RaisePropertyChanged("Column_data_List");
            }
        }
    }
    public ICommand ClickCommand
    private bool _canExecute;
    public ViewModel() {
        _canExecute = true;
        lb_GlobalList = new ObservableCollection < tablegenerateModel > ();
        for (int i = 1; i < 6; i++) {
            //Add To it data here
        }
    }
    public ViewModel(tablegenerateModel tablegenerateModels) //IT WILL BE CALLED WHEN BUTTON WILL BE CLICKED (see tablegenerateModel class ICommand for it)
        {
            Column_data_List = new ObservableCollection < column_Data > ();
            for (int i = 1; i < tablegenerateModels.NumberOfColumns; i++) { //Add data here
            }
            MessageBox.Show("The NumberOfColumns value is:" + tablegenerateModels.NumberOfColumns);
        }
}
}

And View is:

 <Window x:Class="PyXgen.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:vM="clr-namespace:PyXgen" Title="MainWindow" Height="350" Width="525">
    <Window.DataContext>
        <vM:ViewModel></vM:ViewModel>
    </Window.DataContext>
    <Grid Name="ButtonsContainer">

        <ListBox Grid.Row="1" ItemsSource="{Binding lb_GlobalList}" ScrollViewer.VerticalScrollBarVisibility="Auto" BorderBrush="Gray" Margin="0,30,0,0" Grid.RowSpan="2">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <Grid>
                        <StackPanel>
                            <Grid Margin="0,2">
                                <Grid.ColumnDefinitions>
                                    <ColumnDefinition Width="*" />
                                    <ColumnDefinition Width="*" />
                                </Grid.ColumnDefinitions>
                                <Grid.RowDefinitions>
                                    <RowDefinition Height="45" />
                                    <RowDefinition Height="45" />
                                    <RowDefinition Height="45" />
                                    <RowDefinition Height="*" />
                                    <RowDefinition Height="*" />
                                    <RowDefinition Height="*" />
                                </Grid.RowDefinitions>
                                <Grid Grid.Row="4">
                                    <StackPanel>
                                        <Grid Margin="0,2">

                                            Grid.Row="0" Width="80px" Height="20px" Margin="20,5,0,0" Name="fname4"/>
                                            <Button Grid.Row="1" Grid.Column="1" Height="25" Width="70" Content="Create" Command="{Binding CreatColumnCommand}" HorizontalAlignment="Center" VerticalAlignment="Center"></Button>
                                        </Grid>
                                    </StackPanel>
                                </Grid>
                                <Grid Margin="0,2" Grid.Row="5">
                                    <DataGrid x:Name="gvSelectedCourses" Grid.Column="1" HorizontalAlignment="Center" ItemsSource="{Binding Column_data_List , Mode=TwoWay}" AutoGenerateColumns="False" Width="450">
                                        <DataGrid.Columns>
                                            <DataGridTextColumn Header="Column Name" Binding="{Binding  ,Mode=TwoWay}" Width="150" />
                                        </DataGrid.Columns>
                                    </DataGrid>
                                </Grid>
                            </Grid>
                        </StackPanel>
                    </Grid>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>
    </Grid>
</Window>

按钮点击到"_CreatColumnCommand"(在tableGenerateModel类中)将调用ViewModel构造器传递"this"对象来获取输入的整数值以重复输入的整数值的DataGrid行数(该整数值输入在同一类的"NumberOfColumns"文本框中)

现在的问题是如何绑定"_Column_data_List",这样它将添加和更新DataGrid的行(由用户在文本框中输入的整数值)

当前,当我在文本框中输入整数值并单击"创建"按钮时,ViewModel构造器被调用,MessageBox弹出

 MessageBox.Show("The NumberOfColumns value is:" + tablegenerateModels.NumberOfColumns);

如何将这个"_Column_data_List"绑定到这样它将添加或更新DataGrid的行(通过用户在文本框中输入的整数值,在上面的快照中)

谁能帮我一下?

如何绑定DataGrid在我的情况下使用mvvm (ObservableCollection内部ObservableCo

按如下方式更新代码。你已经在tablegeneratedModel中绑定了可观察对象集合,但是你正在更新的是ViewModel上的一个。

public ViewModel(tablegenerateModel tablegenerateModels) //IT WILL BE CALLED WHEN BUTTON WILL BE CLICKED (see tablegenerateModel class ICommand for it)
        {
            tablegenerateModels.Column_data_List = new ObservableCollection<column_Data>();
            for (int i = 1; i < tablegenerateModels.NumberOfColumns; i++)
            {
                Column_data_List.Add(lb_col = new column_Data()
                {
                    Column_Name = "ColumnName" + i,
                    Data_Size = i,
                    Data_types = "Double" + i
                });
            }           
            MessageBox.Show("The NumberOfColumns value is:" + tablegenerateModels.NumberOfColumns);
        }

'CreatColumnCommand'拼写错误,但始终如此,所以这不是你的问题。但是你的'CreatColumnCommand '不在视图模型中,而是在模型中。这是问题所在吗?

在给定的情况下,我必须在ObservableCollection内部有ObservableCollection,但如果你看到我的ViewModel,我试图添加到ViewModel中的Column_data_List,而我应该在模型本身(因为视图不会处理lb_GlobalList和Column_data_List)。