Ipropertybag write a check

DLL work fine with this method, but some custom 3rd-party controls may not. Saving to Office binary file formats is not affected.

Ipropertybag write a check

Table of Contents

Introduction This article details the design, coding, and documentation for a PropertyBag class in C. When classes are designed, they are given the properties that the designer envisages the clients of that class require. For example, an Address class might need PostCode and StreetName properties which are designed into the class.

It ipropertybag write a check common for classes to be used outside of the scope intended by the designer. For instance, our hypothetical Address class starts being used in the U. As a result, the class now needs a ZipCode property.

ipropertybag write a check

On one hand, the Address class code could be extended, the assembly recompiled, and redistributed. On the other hand, if the Address class exposes a PropertyBag object, then the consumers of the class can assign ad-hoc properties ipropertybag write a check the PropertyBag, thus removing the need for potentially costly coding, compilation, and distribution.

Requirements of the PropertyBag class Getting and setting properties The main requirements of the PropertyBag are to enable client classes to add new properties, assign and re-assign values to those properties, and read the current values out of the properties. Ease of use A secondary feature is to design and implement the class in such a way as to make the class interface very intuitive, and easy to use.

To achieve this, an indexer is used in the PropertyBag class when accessing the Property class. Type-safe collections were considered, but a decision was taken to avoid over-complicating the code; type-safe collections will be the subject of a future article instead.

Inner classes were used to simplify the PropertyBag interface, as will be demonstrated further in this article. Deal with the existing properties intuitively Another feature is to take account of the "real" properties of the class that contains the PropertyBag.

For instance, if the parent class is the Address class which already describes a genuine property called Line1and a client of the Address class attempts to add a PostCode property to the Address class' PropertyBag, then the PropertyBag's PostCode property will refer to the "real" property in the Address class, and not an ad-hoc property with a duplicated name in the PropertyBag.

Use of reflection within the PropertyBag class will enable this requirement to be implemented. Implement updating and updated events on individual properties The properties within the PropertyBag class need to implement events such that an event subscriber can be notified when a particular property within the PropertyBag has been updated.

The events to be implemented are Updating and Updated. The Updating event will include a mechanism for signaling back to the property that generated the event that the update is to be cancelled, enabling event handlers to validate the proposed new value, and reject the new value if it fails validation.

The article assumes that the reader has a good understanding of implementing events and delegates in C. This topic is covered in the article Using Events and Delegates in C.

For instance, if the PropertyBag in the Address class can be used by a client to add a new ZipCode property. The class that added the ZipCode property can subscribe to the Updating event, and reject all new values that are non-numeric.

Serializability The PropertyBag and Property objects need to be serializable such that, provided that the owner object the Address class in this example is serializable, then the PropertyBag and Property objects will also serialize.

Thread safety The final requirement is for the PropertyBag class to be thread-safe. Implementing events forces a designer to think about scenarios where those events may be consumed. Event handlers are useful within single threaded applications, but are often even more useful in multi-threaded applications, with a change to a property value in one thread, raising an event in another i.

The writing of properties, and the reading of properties that can be written within the PropertyBag implementation must implement locking to ensure thread safety. Conclusion The PropertyBag class is a useful utility to include in general purpose classes to provide support for the introduction of ad-hoc properties during post-design.

Its implementation will practically demonstrate indexers, inner classes, reflection, events, and thread-safety. Starting at the end- Consuming the PropertyBag class Basic usage The best introduction to the PropertyBag is to see it being used in anger by a client.

The example code uses the Address class which has a number of its own properties, and aggregates an instance of the PropertyBag. Here is a code snippet for the consumer Main in a console applicationusing the PropertyBag in its most basic form, to create a new property in the bag, and an update of the value of that property: Value ; The example code is straightforward.

It also has a Properties property which exposes an instance of the PropertyBag class. The developer needs to add a ZipCode property to the class, and does so by manipulating the PropertyBag instance, without any re-coding. Simply setting the Value using an index for the first time causes a new property to be added into the bag.

Subsequent uses of the same index will cause the Value to be updated. Adding "real" properties into the PropertyBag What happens when the developer decides to add a property called Line1 to the property bag?

Having two different Line1 properties, one indexed by objAdress. Line1, and the other indexed by objAddress. Value would introduce data duplication.

IPropertyBag::Write can do more magic than meets the eye. If the variant it's been passed contains an interface pointer, it will be queried for the IPersistPropertyBag interface. If the query yields an interface pointer, it will be used recursively. The IPersist Interface Family. At run time, most objects maintain certain information about their current state. interface IPersistStream: IPersist { // Check the object for changes since it was last saved. HRESULT IsDirty(void); // Load the object's state from the stream. Below is a simple implementation of the IPropertyBag::Write. This page contains top rated real world C# (CSharp) examples of IPropertyBag extracted from open source projects. You can rate examples to help us improve the quality of examples.

The following code snippet demonstrates how the PropertyBag class deals with this situation:Specifies whether whether the encoder should check for data consistency across passes when performing two-pass VBR encoding.

Read-write. Constant for IPropertyBag. Available only by using IPropertyStore. Data Type. VT_BOOL. Default Value. VARIANT_TRUE. Remarks. Now we can use these methods to retrieve the wanted value from the incoming message, and write it into ReceivedFileName in the context.

This way we can . IPropertyBag::Write can do more magic than meets the eye. If the variant it's been passed contains an interface pointer, it will be queried for the IPersistPropertyBag interface. If the query yields an interface pointer, it will be used recursively. Acknowledgements in BizTalk.

IPropertyBag pb, bool fClearDirty, bool fSaveAllProperties) Now if the Acknowledgement is expected to be Static then Hardcode the Message in the Send Pipeline else write the business logic for creating the response message with the Pipeline component. This page contains top rated real world C# (CSharp) examples of IPropertyBag extracted from open source projects.

You can rate examples to help us improve the quality of examples. /// Ovverrides the TranslateStartElement function to check if the current node is the node which contains the image(as base64String) /// If so, the function, reads the value of the node and saves the base64String as a jpg file in the temporary data store.

Accessing all context properties in a custom BizTalk pipeline component