某些项目未通过 ItemsSource 显示在 ItemsControl 中

Some items not showing up in ItemsControl via ItemsSource

我正在尝试获取一个包含网格的 ItemsControl,以显示 9 个具有不同属性的复选框。然而,只有三个人出现。

我有一个复选框模型 class,它有四个属性代表复选框的内容、grid.row/column 和 isChecked 属性。然后我在我的视图模型中创建了其中的九个并将它们添加到 ObservableCollection.

接下来我将 ItemsControl 的 ItemsSource 绑定到集合。然后,我将复选框控件添加到 ItemsControl 内的网格并绑定适当的属性。

但是,只有前三个复选框出现了,我不知道为什么。我确实通过调试验证了绑定到的集合确实具有正确数量的项目。

这是我的 CheckboxModel class:

public class CheckboxModel : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    private bool _isChecked;
    public bool IsChecked
    {
        get { return _isChecked; }
        set { _isChecked = value; OnPropertyChanged("IsChecked"); }
    }

    private string _content;
    public string Content
    {
        get { return _content; }
        set { _content = value; OnPropertyChanged("Content"); }
    }

    private int _gridRow;
    public int GridRow
    {
        get { return _gridRow; }
        set { _gridRow = value; OnPropertyChanged("GridRow"); }
    }

    private int _gridColumn;
    public int GridColumn
    {
        get { return _gridColumn; }
        set { _gridColumn = value; OnPropertyChanged("GridColumn"); }
    }

    // Create the OnPropertyChanged method to raise the event
    protected void OnPropertyChanged(string name)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (handler != null)
        {
            handler(this, new PropertyChangedEventArgs(name));
        }
    }
}

在我的视图模型中,我创建了一个集合:

private ObservableCollection<CheckboxModel> _checkBoxList = new ObservableCollection<CheckboxModel>();
public ObservableCollection<CheckboxModel> CheckBoxList
{
    get
    {
        return _checkBoxList;
    }
    set
    {
        if (null != value)
        {
            _checkBoxList = value;
            OnPropertyChanged("CheckBoxList");
        }
    }
}

public void CreateCheckboxList()
{
    CheckBoxList.Add(new CheckboxModel { IsChecked = true, Content = "Latitude", GridRow = 0, GridColumn = 0  });
    CheckBoxList.Add(new CheckboxModel { IsChecked = true, Content = "Longitude", GridRow = 1, GridColumn = 0 });
    CheckBoxList.Add(new CheckboxModel { IsChecked = true, Content = "Altitude", GridRow = 2, GridColumn = 0 });
    CheckBoxList.Add(new CheckboxModel { IsChecked = true, Content = "Depth", GridRow = 0, GridColumn = 1 });
    CheckBoxList.Add(new CheckboxModel { IsChecked = true, Content = "Speed", GridRow = 1, GridColumn = 1 });
    CheckBoxList.Add(new CheckboxModel { IsChecked = true, Content = "Heading", GridRow = 2, GridColumn = 1 });
    CheckBoxList.Add(new CheckboxModel { IsChecked = true, Content = "Roll", GridRow = 0, GridColumn = 2 });
    CheckBoxList.Add(new CheckboxModel { IsChecked = true, Content = "Pitch", GridRow = 1, GridColumn = 2 });
    CheckBoxList.Add(new CheckboxModel { IsChecked = true, Content = "VOS", GridRow = 2, GridColumn = 2 }); 
}

最后这是我的 xaml:

<ItemsControl ItemsSource="{Binding CheckBoxList}">
    <ItemsControl.ItemTemplate>
        <DataTemplate>
            <Grid>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="149.6*" />
                    <ColumnDefinition Width="149.6*" />
                    <ColumnDefinition Width="149.6*" />
                </Grid.ColumnDefinitions>
                <Grid.RowDefinitions>
                    <RowDefinition Height="28*" />
                    <RowDefinition Height="28*" />
                    <RowDefinition Height="28*" />
                </Grid.RowDefinitions>
                <CheckBox Grid.Row="{Binding GridRow}"
                          Grid.Column="{Binding GridColumn}"
                          Margin="14,6,63,6"
                          VerticalAlignment="Center"
                          Content="{Binding Content}"
                          IsChecked="{Binding IsChecked}" />
            </Grid>
        </DataTemplate>
    </ItemsControl.ItemTemplate>
</ItemsControl>

这是它的样子:

这是我想要的样子:

我认为您的问题是丢失的物品只是垂直堆叠在看不见的地方。您想要一个 WrapPanel 作为您的项目面板。您还需要确保您的 ItemsControl 本身 auto-sizing 不大于其父项。

<ItemsControl 
    VerticalAlignment="Stretch"
    ItemsSource="{Binding CheckBoxList}">
    <!-- Add this-->
    <ItemsControl.ItemsPanel>
        <ItemsPanelTemplate>
            <WrapPanel 
                Orientation="Vertical" 
                />
        </ItemsPanelTemplate>
    </ItemsControl.ItemsPanel>
    <!-- Done -->

    <ItemsControl.ItemTemplate>
        <DataTemplate>
            <Grid>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="149.6*" />
                    <ColumnDefinition Width="149.6*" />
                    <ColumnDefinition Width="149.6*" />
                </Grid.ColumnDefinitions>
                <Grid.RowDefinitions>
                    <RowDefinition Height="28*" />
                    <RowDefinition Height="28*" />
                    <RowDefinition Height="28*" />
                </Grid.RowDefinitions>
                <CheckBox Grid.Row="{Binding GridRow}"
                    Grid.Column="{Binding GridColumn}"
                    Margin="14,6,63,6"
                    VerticalAlignment="Center"
                    Content="{Binding Content}"
                    IsChecked="{Binding IsChecked}" 
                    />
            </Grid>
        </DataTemplate>
    </ItemsControl.ItemTemplate>
</ItemsControl>

问题是为您 ObservableCollection 中的每个项目创建了一个新网格,但您希望所有项目都使用一个网格。

您可以将 ItemsControlItemsPanel 设置为您的 Grid 并使用 ItemContainerStyle 设置 Grid.RowGrid.Column每个项目容器的附加属性。

这应该有效:

<ItemsControl ItemsSource="{Binding CheckBoxList}">
    <ItemsControl.ItemsPanel>
        <ItemsPanelTemplate>
            <Grid>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="149.6*" />
                    <ColumnDefinition Width="149.6*" />
                    <ColumnDefinition Width="149.6*" />
                </Grid.ColumnDefinitions>
                <Grid.RowDefinitions>
                    <RowDefinition Height="28*" />
                    <RowDefinition Height="28*" />
                    <RowDefinition Height="28*" />
                </Grid.RowDefinitions>
            </Grid>
        </ItemsPanelTemplate>
    </ItemsControl.ItemsPanel>
    <ItemsControl.ItemContainerStyle>
        <Style TargetType="ContentPresenter">
            <Setter Property="Grid.Row" Value="{Binding GridRow}" />
            <Setter Property="Grid.Column" Value="{Binding GridColumn}" />
        </Style>
    </ItemsControl.ItemContainerStyle>
    <ItemsControl.ItemTemplate>
        <DataTemplate>
            <CheckBox Margin="14,6,63,6"
                          VerticalAlignment="Center"
                          Content="{Binding Content}"
                          IsChecked="{Binding IsChecked}" />
        </DataTemplate>
    </ItemsControl.ItemTemplate>
</ItemsControl>