PosCommon Class (POS for .NET v1.12 SDK Documentation)
2/27/2008
PosCommon is the Base class for all specific Interface classes, and all Service Objects indirectly derive from it. PosCommon defines the common properties, methods, and events that the Unified Point of Service (UPOS) specification requires in all device classes.
PosCommon Properties
The following table describes the properties of the PosCommon class available to POS applications.
| Property | Type | Description |
|---|---|---|
bool |
Indicates whether the Service Object and device supports comparing the firmware version in the physical device against that of a firmware file. |
|
PowerReporting enum |
Indicates the power reporting capabilities of the device. |
|
bool |
Indicates whether the device can accumulate and can provide various statistics regarding usage. |
|
bool |
If set to true, some or all of the device statistics can be reset to 0 (zero) using the ResetStatistic method for one update and ResetStatistics method for a list of updates, or updated using the UpdateStatistic method for one update and the UpdateStatistics method for a list of updates with the corresponding specified values. |
|
bool |
Indicates whether the device's firmware can be updated via the UpdateFirmware method. |
|
string |
Indicates the health of the device. |
|
bool |
Indicates whether the device is claimed for exclusive access. |
|
string |
Holds a string identifying the device and the company that manufactured it. |
|
bool |
Indicates whether the device is in an operational state. |
|
string |
UPOS calls it PhysicalDeviceName; OPOS calls it DeviceName. |
|
string |
Set by POS for .NET for Plug and Play devices. For non-Plug and Play devices, DevicePath can be assigned using a configuration file. |
|
bool |
When set to true, the application has requested that the Service Object not deliver events. |
|
PowerNotification enum |
Holds the type of power notification selection made by the application. |
|
PowerState enum |
Holds the current power condition. |
|
string |
Identifies the Service Object supporting the device and the company that produced it. This property is listed as DeviceServiceDescription in the UPOS specification. |
|
System.Version |
Holds the Service Object version number. This property is listed as DeviceServiceVersion in the UPOS specification. |
|
ControlState enum |
Holds the current state of the device. |
|
ISynchronizeInvoke |
Gets or sets the marshalling object for event handler calls from a POS event. |
PosCommon Methods
The following table describes the methods of the PosCommon class available to applications.
| Method | Return Type | Description |
|---|---|---|
string |
Performs a health check on the device. The type of check to be performed is indicated by the HealthCheckLevel parameter. The method also updates the CheckHealthText property. |
|
void |
Requests exclusive access to the device. Service Object writers are advised to only throw exceptions in unexpected conditions; for example, OutOfMemory. Otherwise, Service Objects should return True if the device was claimed and False if a time-out occurred. |
|
void |
Releases the device and its resources. |
|
CompareFirmwareResult |
Determines whether the version of the specified firmware is newer than, older than, or the same as the version of firmware in the physical device. |
|
DirectIOData |
Used to communicate directly with the Service Object. In the UPOS specification, it has two in/out parameters. As used by POS for .NET, this method returns a structure and no in/out parameters. |
|
void |
Opens a device for subsequent input/output processing. |
|
void |
Releases exclusive access to the device. |
|
void |
Resets the specified statistic to zero. Used in POS for .NET for operations on a single statistic. |
|
void |
Resets all statistics for a specified category to 0 (zero). |
|
void |
Resets the specified statistics to 0 (zero). |
|
void |
Resets all statistics associated with a device to 0 (zero). |
|
string |
Retrieves the specified device statistic. Used in POS for .NET for operations on a single statistic. |
|
string |
Retrieves all device statistics. |
|
void |
Retrieves the statistics for the specified category. |
|
void |
Retrieves the specified statistics. |
|
UpdateFirmware |
void |
Updates the firmware of a device with the version of the firmware contained in the specified filename. |
void |
Updates a statistic. Added to POS for .NET for operations on a single statistic. |
|
void |
Updates a list of statistics with the corresponding specified values. |
|
void |
Updates the specified category of statistics with the specified value. |
PosCommon Events
The following table describes the PosCommon class events.
| Method | Description |
|---|---|
Raised by the Service Object to communicate information directly to the application. |
|
Raised by the Service Object to alert the application of a device status change. |
Example
The following code example demonstrates how to use the properties and methods common to all Service Objects to display information about a connected device.
// Create a dervied class of PosCommon
public class PosCommonSample: PosCommon
{
// Implement all base methods and properties.
// ...
}
// Create instances for the example.
PosExplorer explorer = new PosExplorer();
PosCommonSample pcs = new PosCommonSample();
DeviceInfo device = explorer.GetDevice("MSR");
pcs = (PosCommonSample)explorer.CreateInstance(device);
// Open and claim the device, then print information
// about the device to the console.
pcs.Open();
pcs.Claim(1000);
Console.WriteLine("Name: {0}", pcs.DeviceName);
Console.WriteLine("Description: {0}", pcs.DeviceDescription);
Console.WriteLine("Path: {0}", pcs.DevicePath);
Console.WriteLine("Enabled: {0}", pcs.DeviceEnabled);
pcs.Close();