Intersoft ClientUI Documentation
ProcessedItem Property
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Intersoft.Client.UI.Aqua.UXCollection Namespace > UXTreeView Class : ProcessedItem Property






Gets or sets a value that indicates the item that user process when load on demand is active.

Syntax

Visual Basic (Declaration) 
<CategoryAttribute("Common Properties")>
Public Property ProcessedItem As Object
Visual Basic (Usage)Copy Code
Dim instance As UXTreeView
Dim value As Object
 
instance.ProcessedItem = value
 
value = instance.ProcessedItem
C# 
[CategoryAttribute("Common Properties")]
public object ProcessedItem {get; set;}
Delphi 
public read-write property ProcessedItem: TObject; 
JScript 
CategoryAttribute("Common Properties")
public function get,set ProcessedItem : Object
Managed Extensions for C++ 
[CategoryAttribute("Common Properties")]
public: __property Object* get_ProcessedItem();
public: __property void set_ProcessedItem( 
   Object* value
);
C++/CLI 
[CategoryAttribute("Common Properties")]
public:
property Object^ ProcessedItem {
   Object^ get();
   void set (    Object^ value);
}

Example

The following code shows how to implement load on demand in UXTreeView with the LoadOnDemandMode property set to UseProcessedItem. The example is implemented using MVVM pattern.

C# Copy Code
public class CompanyEmployee : ModelBase
{
    private String _name;

    public String Name
    {
        get { return this._name; }
        set
        {
            if (this._name != value)
            {
                this._name = value;
                OnPropertyChanged("Name");
            }
        }
    }
}
C# Copy Code
public class Company : ModelBase
{
    private string _section;
    private ObservableCollection<CompanyEmployee> _employees;

    public string Section
    {
        get { return this._section; }
        set
        {
            if (this._section != value)
            {
                this._section = value;
                OnPropertyChanged("Section");
            }
        }
    }

    public ObservableCollection<CompanyEmployee> Employees
    {
        get { return this._employees; }
        set
        {
            if (this._employees != value)
            {
                this._employees = value;
                OnPropertyChanged("Employees");
            }
        }
    }

    public Company()
    {
        this.Employees = new ObservableCollection<CompanyEmployee>();
    }
}
C# Copy Code
public class CompanyViewModel : ViewModelBase
{
    private ObservableCollection<Company> _companies;
    private object _expandedItem;
    private object _processedItem;

    public ObservableCollection<Company> Companies
    {
        get { return this._companies; }
        set
        {
            if (this._companies != value)
            {
                this._companies = value;
                OnPropertyChanged("Companies");
            }
        }
    }

    public object ExpandedItem
    {
        get { return this._expandedItem; }
        set
        {
            if (this._expandedItem != value)
            {
                this._expandedItem = value;
                Company obj = value as Company;
                ObservableCollection<CompanyEmployee> data = new ObservableCollection<CompanyEmployee>();

                //using thread
                if (obj != null && obj.Employees.Count == 0)
                {
                    var t = new Thread(() =>
                    {
                        try
                        {
                            Thread.Sleep(300);
                            for (int i = 0; i < 20; i++)
                            {
                                data.Add(new CompanyEmployee()
                                {
                                    Name = obj.Section + ", Employee " + i.ToString()
                                });
                            }
                            System.Windows.Deployment.Current.Dispatcher.BeginInvoke(() =>
                            {
                                obj.Employees = data;
                                this.ProcessedItem = value;
                            });
                        }
                        catch
                        {
                            System.Diagnostics.Debug.WriteLine("Debug");
                        }
                    });
                    t.Start();                        
                }
                else
                    this.ProcessedItem = value;
                OnPropertyChanged("ExpandedItem");
            }
        }
    }

    public object ProcessedItem
    {
        get { return this._processedItem; }
        set
        {
            if (this._processedItem != value)
            {
                this._processedItem = value;
                OnPropertyChanged("ProcessedItem");
            }
        }
    }

    public CompanyViewModel()
    {
        this.LoadData();
    }

    private void LoadData()
    {
        this.Companies = new ObservableCollection<Company>();
        this.Companies.Add(new Company() { Section = "Human Resource" });
        this.Companies.Add(new Company() { Section = "Development and Training" });
        this.Companies.Add(new Company() { Section = "Developer" });
        this.Companies.Add(new Company() { Section = "Support" });
        this.Companies.Add(new Company() { Section = "Project Manager" });
    }
}
XAML Copy Code
<Intersoft:UXPage>
    <Intersoft:UXPage.Resources>
        <ViewModel:CompanyViewModel x:Key="CompanyViewModel" />
    </Intersoft:UXPage.Resources>
    <Grid x:Name="LayoutRoot">
        <Grid.Resources>
            <Intersoft:HierarchicalDataTemplate x:Key="CompanyEmployeeTemplate" ItemsSource="{Binding Employees}">
                <TextBlock Text="{Binding Name}" />
            </Intersoft:HierarchicalDataTemplate>            
            <Intersoft:HierarchicalDataTemplate x:Key="CompanyTemplate" ItemTemplate="{StaticResource CompanyEmployeeTemplate}" ItemsSource="{Binding Employees}">
                <TextBlock Text="{Binding Section}" />
            </Intersoft:HierarchicalDataTemplate>
        </Grid.Resources>
        <Intersoft:UXTreeView TreeExpandMode="Multiple" Height="300" 
                IsLoadOnDemand="True" BusyLatency="0.002" LoadOnDemandMode="UseProcessedItem"
                ExpandedItem="{Binding ExpandedItem, Mode=TwoWay}" 
                ProcessedItem="{Binding ProcessedItem, Mode=TwoWay}" 
                ItemsSource="{Binding Companies}" EnableSlidingAnimation"False"
                DataContext="{StaticResource CompanyViewModel}" 
                ItemTemplate="{StaticResource CompanyTemplate}">
        </Intersoft:UXTreeView>
    </Grid>
</Intersoft:UXPage>

Remarks

For more advanced scenarios, UXTreeView can also completely delegate the child data retrieval process to your application's logic by setting the LoadOnDemandMode property to UseProcessedItem. This mode is ideal for performance-critical data applications where loading all hierarchical data is not feasible due to the data size. In such scenario, you may want to load only several levels of the data initially, then load the rest of the items on demand as they are being expanded.

UXTreeView is specifically designed to elegantly achieve this scenario using MVVM pattern implementation. UXTreeView exposes ExpandedItem property that you can bind in the ViewModel. This allows you to interact with the entity being expanded and write your own logic to retrieve the child items in the ViewModel. Once the child items become available, you assign the original entity to the ProcessedItem property to notify the control that the loading process is completed.

In this mode, a busy indicator will be automatically displayed in each expanded item during the loading progress. You can determine how soon the busy indicator should appear by setting the BusyLatency property to a value in seconds measurement. The default value is 0.1s.

Requirements

Target Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, Windows Vista, Windows Server 2008 family

See Also

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