MessageQueue::MessageReadPropertyFilter Property
Gets or sets the property filter for receiving or peeking messages.
Assembly: System.Messaging (in System.Messaging.dll)
public: [BrowsableAttribute(false)] [MessagingDescriptionAttribute("MQ_MessageReadPropertyFilter")] property MessagePropertyFilter^ MessageReadPropertyFilter { MessagePropertyFilter^ get(); void set(MessagePropertyFilter^ value); }
Property Value
Type: System.Messaging::MessagePropertyFilter^The MessagePropertyFilter used by the queue to filter the set of properties it receives or peeks for each message.
| Exception | Condition |
|---|---|
| ArgumentException | The filter is null. |
This filter is a set of Boolean values restricting the message properties that the MessageQueue receives or peeks. When the MessageQueue receives or peeks a message from the server queue, it retrieves only those properties for which the MessageReadPropertyFilter value is true.
The following shows initial property values for the MessageReadPropertyFilter property. These settings are identical to calling SetDefaults on a MessagePropertyFilter.
Property | Default value |
|---|---|
false | |
false | |
true | |
false | |
true | |
false | |
false | |
false | |
false | |
true | |
false | |
true | |
1024 bytes | |
255 bytes | |
255 bytes | |
false | |
false | |
false | |
false | |
false | |
false | |
true | |
false | |
false | |
true | |
false | |
false | |
false | |
true | |
false | |
false | |
false | |
true | |
false | |
false | |
false | |
false | |
false | |
false | |
false | |
false | |
false | |
false |
The following table shows whether this property is available in various Workgroup modes.
Workgroup mode | Available |
|---|---|
Local computer | Yes |
Local computer and direct format name | Yes |
Remote computer | Yes |
Remote computer and direct format name | Yes |
The following code example uses the MessageReadPropertyFilter to restrict the message properties received.
#using <system.dll> #using <system.messaging.dll> using namespace System; using namespace System::Messaging; ref class MyNewQueue { public: //************************************************* // Retrieves the default properties for a Message. //************************************************* void RetrieveDefaultProperties() { // Connect to a message queue. MessageQueue^ myQueue = gcnew MessageQueue( ".\\myQueue" ); // Specify to retrieve the default properties only. myQueue->MessageReadPropertyFilter->SetDefaults(); // Set the formatter for the Message. array<Type^>^p = gcnew array<Type^>(1); p[ 0 ] = String::typeid; myQueue->Formatter = gcnew XmlMessageFormatter( p ); // Receive the first message in the queue. Message^ myMessage = myQueue->Receive(); // Display selected properties. Console::WriteLine( "Label: {0}", myMessage->Label ); Console::WriteLine( "Body: {0}", static_cast<String^>(myMessage->Body) ); return; } //************************************************* // Retrieves all properties for a Message. //************************************************* void RetrieveAllProperties() { // Connect to a message queue. MessageQueue^ myQueue = gcnew MessageQueue( ".\\myQueue" ); // Specify to retrieve all properties. myQueue->MessageReadPropertyFilter->SetAll(); // Set the formatter for the Message. array<Type^>^p = gcnew array<Type^>(1); p[ 0 ] = String::typeid; myQueue->Formatter = gcnew XmlMessageFormatter( p ); // Receive the first message in the queue. Message^ myMessage = myQueue->Receive(); // Display selected properties. Console::WriteLine( "Encryption algorithm: {0}", myMessage->EncryptionAlgorithm.ToString() ); Console::WriteLine( "Body: {0}", myMessage->Body ); return; } //************************************************* // Retrieves application-specific properties for a // Message. //************************************************* void RetrieveSelectedProperties() { // Connect to a message queue. MessageQueue^ myQueue = gcnew MessageQueue( ".\\myQueue" ); // Specify to retrieve selected properties. MessagePropertyFilter^ myFilter = gcnew MessagePropertyFilter; myFilter->ClearAll(); // The following list is a random subset of available properties. myFilter->Body = true; myFilter->Label = true; myFilter->MessageType = true; myFilter->Priority = true; myQueue->MessageReadPropertyFilter = myFilter; // Set the formatter for the Message. array<Type^>^p = gcnew array<Type^>(1); p[ 0 ] = String::typeid; myQueue->Formatter = gcnew XmlMessageFormatter( p ); // Receive the first message in the queue. Message^ myMessage = myQueue->Receive(); // Display selected properties. Console::WriteLine( "Message type: {0}", myMessage->MessageType.ToString() ); Console::WriteLine( "Priority: {0}", myMessage->Priority.ToString() ); return; } }; //************************************************* // Provides an entry point into the application. // // This example retrieves specific groups of Message // properties. //************************************************* int main() { // Create a new instance of the class. MyNewQueue^ myNewQueue = gcnew MyNewQueue; // Retrieve specific sets of Message properties. myNewQueue->RetrieveDefaultProperties(); myNewQueue->RetrieveAllProperties(); myNewQueue->RetrieveSelectedProperties(); return 0; }
Available since 1.1