MapItem.Tag Property

Gets or sets the object that contains data related to a map item.

Namespace: DevExpress.XtraMap

Assembly: DevExpress.XtraMap.v20.2.dll

NuGet Package: DevExpress.Win.Map

Declaration

C#

[DefaultValue(null)]
public object Tag { get; set; }

VB.NET

<DefaultValue(Nothing)>
Public Property Tag As Object

Property Value

Type	Default	Description
Object	*null*	A Object that contains information about the map item.

Remarks

Any type derived from the Object class can be assigned to this property. Use it to store data associated with a map item.

Example

The following example adds two pushpins to a map item storage. Each pushpin’s Tag property is initialized with an object of the ItemInfo type. The storage’s DataChanged event handler defines pushpins’ visibility based on the ItemInfo.IsOpened property value.

C#

VectorItemsLayer vectorLayer;
//...
private void Form1_Load(object sender, EventArgs e) {

    vectorLayer = new VectorItemsLayer();
    mapControl1.Layers.Add(vectorLayer);

    MapItemStorage storage = new MapItemStorage();
    vectorLayer.Data = storage;

    storage.DataChanged += Storage_DataChanged;

    MapPushpin pushpin1 = new MapPushpin();
    pushpin1.Location = new GeoPoint(48.862644, 2.336578);
    pushpin1.Tag = new ItemInfo { IsOpened = true };
    storage.Items.Add(pushpin1);

    MapPushpin pushpin2 = new MapPushpin();
    pushpin2.Location = new GeoPoint(59.9398, 30.3146);
    pushpin2.Tag = new ItemInfo { IsOpened = false };
    storage.Items.Add(pushpin2);

}

private void Storage_DataChanged(object sender, DataAdapterChangedEventArgs e) {
    foreach (MapItem item in vectorLayer.Data.Items) {
        ItemInfo info = item.Tag as ItemInfo;
        item.Visible = info.IsOpened;
    }
}

public class ItemInfo {
    public bool IsOpened { get; set; }
}

VB.NET

Private vectorLayer As VectorItemsLayer

  '...
  Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs)
      vectorLayer = New VectorItemsLayer()
      mapControl1.Layers.Add(vectorLayer)
      Dim storage As MapItemStorage = New MapItemStorage()
      vectorLayer.Data = storage
      storage.DataChanged += AddressOf Storage_DataChanged
      Dim pushpin1 As MapPushpin = New MapPushpin()
      pushpin1.Location = New GeoPoint(48.862644, 2.336578)
      pushpin1.Tag = New ItemInfo With {
          .IsOpened = True
      }
      storage.Items.Add(pushpin1)
      Dim pushpin2 As MapPushpin = New MapPushpin()
      pushpin2.Location = New GeoPoint(59.9398, 30.3146)
      pushpin2.Tag = New ItemInfo With {
          .IsOpened = False
      }
      storage.Items.Add(pushpin2)
  End Sub

  Private Sub Storage_DataChanged(ByVal sender As Object, ByVal e As DataAdapterChangedEventArgs)
      For Each item As MapItem In vectorLayer.Data.Items
          Dim info As ItemInfo = TryCast(item.Tag, ItemInfo)
          item.Visible = info.IsOpened
      Next
  End Sub

  Public Class ItemInfo
      Public Property IsOpened As Boolean
  End Class