FilterDescriptors Property (QueryDescriptor)

Visual Basic (Declaration)
Visual Basic (Usage)
C#
C++/CLI

Public Property FilterDescriptors As CompositeFilterDescriptorCollection

Dim instance As QueryDescriptor
Dim value As CompositeFilterDescriptorCollection
 
instance.FilterDescriptors = value
 
value = instance.FilterDescriptors

public CompositeFilterDescriptorCollection FilterDescriptors {get; set;}

public:
property CompositeFilterDescriptorCollection^ FilterDescriptors {
   CompositeFilterDescriptorCollection^ get();
   void set (    CompositeFilterDescriptorCollection^ value);
}

FilterDescriptors is a property that contains a collection of FilterDescriptor that hold filtering information.

The following example shows how to instantiate a QueryDescriptor programmatically and demonstrate the use of FilterDescriptors, SortDescriptors and PageDescriptors in the QueryDescriptor object.

CS	Copy Code
QueryDescriptor queryDescriptor = new QueryDescriptor(); // filtering // get records that have // (UnitPrice >= 0 AND UnitPrice < 50) OR (UnitPrice == 0) CompositeFilterDescriptorCollection groupFilter1 = new CompositeFilterDescriptorCollection(); groupFilter1.LogicalOperator = FilterCompositionLogicalOperator.And; groupFilter1.Add( new FilterDescriptor() { PropertyName = "UnitPrice", Operator = FilterOperator.IsGreaterThanOrEqualTo, Value = 0 } ); groupFilter1.Add( new FilterDescriptor() { PropertyName = "UnitPrice", Operator = FilterOperator.IsLessThan, Value = 50 } ); CompositeFilterDescriptorCollection groupFilter2 = new CompositeFilterDescriptorCollection(); groupFilter2.LogicalOperator = FilterCompositionLogicalOperator.And; groupFilter2.Add( new FilterDescriptor() { PropertyName = "UnitsInStock", Operator = FilterOperator.IsEqualTo, Value = 0 } ); queryDescriptor.FilterDescriptors.LogicalOperator = FilterCompositionLogicalOperator.Or; queryDescriptor.FilterDescriptors.Add(groupFilter1); queryDescriptor.FilterDescriptors.Add(groupFilter2); // paging // get the record 6 - 10 queryDescriptor.PageDescriptor.PageSize = 5; queryDescriptor.PageDescriptor.PageIndex = 1; // sorting // sort by category ascending then by product id descending queryDescriptor.SortDescriptors.Add( new SortDescriptor() { PropertyName = "CategoryID", Direction = System.ComponentModel.ListSortDirection.Ascending } ); queryDescriptor.SortDescriptors.Add( new SortDescriptor() { PropertyName = "ProductID", Direction = System.ComponentModel.ListSortDirection.Descending } );

CS

Copy Code

QueryDescriptor queryDescriptor = new QueryDescriptor();

// filtering
// get records that have
// (UnitPrice >= 0 AND UnitPrice < 50) OR (UnitPrice == 0)
CompositeFilterDescriptorCollection groupFilter1 = new CompositeFilterDescriptorCollection();

groupFilter1.LogicalOperator = FilterCompositionLogicalOperator.And;
groupFilter1.Add(
    new FilterDescriptor()
    {
        PropertyName = "UnitPrice",
        Operator = FilterOperator.IsGreaterThanOrEqualTo, Value = 0
    }
);
groupFilter1.Add(
    new FilterDescriptor()
    {
        PropertyName = "UnitPrice",
        Operator = FilterOperator.IsLessThan, Value = 50
    }
);

CompositeFilterDescriptorCollection groupFilter2 = new CompositeFilterDescriptorCollection();

groupFilter2.LogicalOperator = FilterCompositionLogicalOperator.And;
groupFilter2.Add(
    new FilterDescriptor()
    {
        PropertyName = "UnitsInStock",
        Operator = FilterOperator.IsEqualTo, Value = 0
    }
);

queryDescriptor.FilterDescriptors.LogicalOperator = FilterCompositionLogicalOperator.Or;

queryDescriptor.FilterDescriptors.Add(groupFilter1);
queryDescriptor.FilterDescriptors.Add(groupFilter2);

// paging
// get the record 6 - 10
queryDescriptor.PageDescriptor.PageSize = 5;
queryDescriptor.PageDescriptor.PageIndex = 1;

// sorting
// sort by category ascending then by product id descending
queryDescriptor.SortDescriptors.Add(
    new SortDescriptor()
    {
        PropertyName = "CategoryID",
        Direction = System.ComponentModel.ListSortDirection.Ascending
    }
);
queryDescriptor.SortDescriptors.Add(
    new SortDescriptor()
    {
        PropertyName = "ProductID",
        Direction = System.ComponentModel.ListSortDirection.Descending
    }
);

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

QueryDescriptor Class
QueryDescriptor Members