Leadtools.Multimedia Namespace > Devices Class > Item Property : Item(String) Property |
Exception | Description |
---|---|
System.ArgumentOutOfRangeException | The exception that is thrown when the value of an argument is outside the allowable range of values as defined by the invoked method. |
System.NullReferenceException | The exception that is thrown when there is an attempt to dereference a null object reference. |
This property provides the ability to access a specific item in the collection by using the following syntax: myCollection[index]
The C# language uses the this keyword to define the indexers instead of implementing the Item property. Visual Basic implements Item as a default property, which provides the same indexing functionality.
Device names are unique. An application can use this method to find a specific device. A Device name can be retrieved with the Device.Name property or by using the LTMM DirectShow Filter List Utility.
If the method fails, an error is raised. For more information, refer to the Error Codes.
Imports Leadtools Imports Leadtools.Multimedia Imports LeadtoolsMultimediaExamples.Fixtures Public _result As Boolean = False Public _form As CaptureCtrlForm = New CaptureCtrlForm() Public Sub IndexContainsExample() ' reference the capture control Dim capturectrl As CaptureCtrl = _form.CaptureCtrl Try ' select a video device, use your device name here instead of Analog If capturectrl.VideoDevices("Analog") Is Nothing Then Throw New Exception("No Analog video tuner device available") End If capturectrl.VideoDevices("Analog").Selected = True ' reference the video devices object Dim devices As Devices = capturectrl.VideoDevices ' check the index of a USB video device Dim i As Integer = devices.IndexOf("USB") Dim dev As Device = Nothing If i > -1 Then ' access the input via the collection indexer dev = devices(i) End If ' check if the collection contains this input ' (it should we just got it with IndexOf above) If devices.Contains(dev) Then ' set the result to what we expect _result = True End If Catch e1 As Exception _result = False End Try End Sub
using Leadtools; using Leadtools.Multimedia; using LeadtoolsMultimediaExamples.Fixtures; public bool _result = false; public CaptureCtrlForm _form = new CaptureCtrlForm(); public void IndexContainsExample() { // reference the capture control CaptureCtrl capturectrl = _form.CaptureCtrl; try { // select a video device, use your device name here instead of Analog if (capturectrl.VideoDevices["Analog"] == null) throw new Exception("No Analog video tuner device available"); capturectrl.VideoDevices["Analog"].Selected = true; // reference the video devices object Devices devices = capturectrl.VideoDevices; // check the index of a USB video device int i = devices.IndexOf("USB"); Device dev = null; if (i > -1) // access the input via the collection indexer dev = devices[i]; // check whether the collection contains this input // (it should we just got it with IndexOf above) if (devices.Contains(dev)) { // set the result to what we expect _result = true; } } catch (Exception) { _result = false; } }