Question

我正在使用XamDataGrid并且需要每一行都是分层的（有几个子节点也是分层的）。它必须按需加载其数据并具有动态子列基于我查询的服务器返回的结果。

快进一点：

我已经开始使用ITypedList和ICustomPropertyDescriptor动态添加/删除属性，以便可以操作相应的列。无济于事。
我尝试在后面的代码中动态更改FieldLayouts，用于由ParentFieldLayoutKey指定的每个特定层次结构。但是，如果我修改了我的任何字段布局，它会直观地将更改应用于所有字段布局，但在后面的代码中，实际上只修改了所选的字段布局。 为什么我不修改一个FieldLayout而不更改所有这些？
我还尝试使用包含与 ESTABLISH 关系的表的DataSet所需的层次结构，但到目前为止，这样做无法按需加载数据。除非有某种方法可以做到这一点，否则我无法在infragistics docs中的任何地方找到它？

以下是我的要求：

必须是分层的
必须按需加载数据（在展开时）
在运行时/展开时/查询服务器时，不应完全知道列。

问题：

是否可以使用XamDataGrid实现所有这些功能？

编辑：是的。这是可能的。

Answer 1

这是我的版本。这基本上可以满足您的需求。在子fieldlayout中，动态添加列并相应地执行数据绑定

型号：

public class Country
{
    private string _name;
    public string Name
    {
        get { return this._name; }
        set { this._name = value; }
    }
    public ObservableCollection<State> States { get; set; }
}

public class State
{
    private readonly Dictionary<string, object> _info = new Dictionary<string, object>();

    /// <summary>
    /// Attributes of the state can be added dynamically (key will be the attribtue name etc...)
    /// </summary>
    /// <param name="key"></param>
    /// <returns></returns>
    public object this[string key]
    {
        get
        {
            return this._info[key];
        }
        set
        {
            this._info[key] = value;
        }
    }

    public string StateName { get; set; }
}

行为：

public class GridFieldLayoutBehaviour : Behavior<XamDataGrid>
{
    protected override void OnAttached()
    {
        base.OnAttached();

        this.AssociatedObject.FieldLayoutInitialized += OnFieldLayoutInitialized;            
        this.AssociatedObject.RecordExpanded += OnRecordExpanded;
    }

    void OnRecordExpanded(object sender, Infragistics.Windows.DataPresenter.Events.RecordExpandedEventArgs e)
    {
        ((ViewModel)this.AssociatedObject.DataContext).AddStateAttributes();
    }

    void OnFieldLayoutInitialized(object sender, Infragistics.Windows.DataPresenter.Events.FieldLayoutInitializedEventArgs e)
    {
        if( e.FieldLayout.ParentFieldName == "States")
        {
            ((ViewModel)this.AssociatedObject.DataContext).GridFieldLayout = e.FieldLayout;
        }            
    }

    protected override void OnDetaching()
    {
        base.OnDetaching();            
        this.AssociatedObject.FieldLayoutInitialized -= OnFieldLayoutInitialized;
        this.AssociatedObject.RecordExpanded -= OnRecordExpanded;
    }
}

视图模型：

public class ViewModel
{
    #region Private Fields
    private readonly ObservableCollection<Country> _countries = new ObservableCollection<Country>();        
    private readonly List<string> _stateTotalAttributes = new List<string>();        
    #endregion

    public ViewModel()
    {
        FillData();

        var stateAttributes = new string[] {"Population", "Unemployment Rate", "Capital", "Governor", "TimeZone", "Area"};
        foreach (var stateAttribute in stateAttributes)
            _stateTotalAttributes.Add(stateAttribute);                            
    }

    public ObservableCollection<Country> Countries
    {
        get { return this._countries; }
    }

    public FieldLayout GridFieldLayout { get; set; }

    /// <summary>
    /// Country and the states are populated
    /// </summary>
    private void FillData()
    {
        var country = new Country();
        country.States = new ObservableCollection<State>();            
        country.Name = "USA";            

        var xdoc = XDocument.Load("states_data.xml");
        foreach (var state in xdoc.Descendants("states").Descendants())
        {
            var newState = new State();
            newState.StateName = state.Attributes("name").FirstOrDefault().Value;
            newState["Unemployment Rate"] = state.Attributes("unemployment-rate").FirstOrDefault().Value;
            newState["Capital"] = state.Attributes("capital").FirstOrDefault().Value;
            newState["Governor"] = state.Attributes("governor").FirstOrDefault().Value;
            newState["Area"] = state.Attributes("area").FirstOrDefault().Value;
            newState["TimeZone"] = state.Attributes("timezone").FirstOrDefault().Value;
            newState["Population"] = state.Attributes("population").FirstOrDefault().Value;

            country.States.Add(newState);
        }

        _countries.Add(country);
    }

    public void AddStateAttributes()
    {
        GridFieldLayout.Fields.BeginUpdate();

        // Remove the current columns (except for StateName)
        var removableFields = GridFieldLayout.Fields.Where(f => f.Name != "StateName");
        removableFields.ToList().ForEach(field => GridFieldLayout.Fields.Remove(field));

        // Figure out what state attributes to add
        var random = new Random(DateTime.Now.Millisecond);
        var numCols = random.Next(1, 6);
        var colsToAdd = GetStateAttributes(numCols, random);

        // Finally add the new ones'
        foreach (var col in colsToAdd)
        {
            var field = new UnboundField();
            field.Name = col;
            field.Binding = new Binding()
            {
                Mode = BindingMode.TwoWay,
                Path = new PropertyPath(string.Format("[{0}]",  col)),
                UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged
            };

            GridFieldLayout.Fields.Add(field);
        }
        GridFieldLayout.Fields.EndUpdate();
    }

    private List<string> GetStateAttributes(int numCols, Random random)
    {            
        List<string> colsToAdd = new List<string>();
        for( int i = 0; i < numCols; i++)
        {
            int idx = random.Next(1, 6) - 1;
            if(colsToAdd.Contains(_stateTotalAttributes[idx]) == false)
            {
                colsToAdd.Add(_stateTotalAttributes[idx]);
            }
        }
        return colsToAdd;
    }
}

XAML：

    <igDP:XamDataGrid DataSource="{Binding Countries}" >
        <i:Interaction.Behaviors>
            <local:GridFieldLayoutBehaviour/>
        </i:Interaction.Behaviors>
    </igDP:XamDataGrid>

States_Data.xml：

<states>
  <state name="New York" population="19,651,127" unemployment-rate="" capital="Albany" governor="Andrew Cuomo" timezone="EST" area="54,556 sq mi"></state>
  <state name="New Hampshire" population="1,323,459 " unemployment-rate="" capital="Concord" governor="Maggie Hassan" timezone="EST" area="9,304 sq mi"></state>
</states>

此致 Vishwa

Answer 2

想出来。

由于我无法粘贴代码（从技术上讲，它属于我所工作的公司），我想我只需要解决基本解释我所做的事情。

我创建了两个包装器，一个用于包装我的对象以暴露/创建层次结构（AutoGeneratedColumns =“True”，默认情况下，假设对象内部的对象集合是对象的CHILDREN），以及一个ITypedList来包装新的包装器，因此您可以动态地向其添加属性。

我希望这篇文章至少能提供一些信息。

（WPF）XamDataGrid +分层+按需加载+动态列

2 个答案: