DataConnectionManager Class

Artículo
02/28/2011

Represents a shared set of data connection objects that are created on demand and managed by Visual Studio.

Inheritance Hierarchy

System.Object
Microsoft.VisualStudio.Data.DataConnectionManager

Namespace: Microsoft.VisualStudio.Data
Assembly: Microsoft.VisualStudio.Data (in Microsoft.VisualStudio.Data.dll)

Syntax

'Declaración
<GuidAttribute("E7A0D4E0-D0E4-4afa-A8A1-DD4636073D98")> _
Public MustInherit Class DataConnectionManager _
    Implements ICollection(Of DataConnection), IEnumerable(Of DataConnection),  _
    IEnumerable

[GuidAttribute("E7A0D4E0-D0E4-4afa-A8A1-DD4636073D98")]
public abstract class DataConnectionManager : ICollection<DataConnection>, 
    IEnumerable<DataConnection>, IEnumerable

[GuidAttribute(L"E7A0D4E0-D0E4-4afa-A8A1-DD4636073D98")]
public ref class DataConnectionManager abstract : ICollection<DataConnection^>, 
    IEnumerable<DataConnection^>, IEnumerable

[<AbstractClass>]
[<GuidAttribute("E7A0D4E0-D0E4-4afa-A8A1-DD4636073D98")>]
type DataConnectionManager =  
    class
        interface ICollection<DataConnection>
        interface IEnumerable<DataConnection>
        interface IEnumerable
    end

public abstract class DataConnectionManager implements ICollection<DataConnection>, IEnumerable<DataConnection>, IEnumerable

The DataConnectionManager type exposes the following members.

Constructors

	Name	Description
	DataConnectionManager	Class constructor.

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Properties

	Name	Description
	Count	Retrieves a count of the number of data connections currently being managed.

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Methods

	Name	Description
	CopyTo	Copies the set of currently managed data connections to an array, starting at the specified array index.
	CreateDataConnection	Initializes a data connection. This method should not be called by client code.
	Equals	Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
	GetDataConnection(Guid, String, Boolean)	Retrieves a data connection that is equivalent to the specified connection information.
	GetDataConnection(Guid, String, Boolean, Boolean)	Retrieves a data connection that is equivalent to the specified connection information, with an indication whether the connection information is updated.
	GetHashCode	Serves as a hash function for a particular type. (Inherited from Object.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	InvalidateDataConnection	Invalidates a currently managed data connection that matches the specified connection information, if any.
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	ToString	Returns a string that represents the current object. (Inherited from Object.)

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Explicit Interface Implementations

	Name	Description
	ICollection<DataConnection>.Add	Adds a data source to the DDEX data connection collection.
	ICollection<DataConnection>.Clear	Clears the DDEX data connection collection.
	ICollection<DataConnection>.Contains	Tests whether the DDEX data connection collection contains a specified connection.
	IEnumerable<DataConnection>.GetEnumerator	Retrieves an enumerator for iterating the DDEX data connection collection.
	IEnumerable.GetEnumerator	Retrieves an IEnumerator object with which to iterate through the collection.
	ICollection<DataConnection>.IsReadOnly	Tests whether the data connection collection is read only.
	ICollection<DataConnection>.Remove	Removes a data connection from the DDEX data connection collection.

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Remarks

Because the architecture of VSPackages and the Visual Studio services model, it is difficult to pass around objects, such as data connections, that one would typically use globally. Normally, an application makes a single connection to a database and then use it throughout. In Visual Studio different features are implemented in different VSPackages, therefore, the only way to connect features is by using Visual Studio services.

If one feature, for example the Server Explorer, creates a connection for use at design time, and another feature, for example the Data Source Wizard or DataSet designer, wants to use this connection, they need a way to access the connection that was created in Server Explorer.

The data connection manager lets you share these connections, so long as the client has a way to identify the connection. This identifying information is a DDEX provider GUID and a connection string.

A typical data connection manager scenario is implementing drag/drop operations, where the clipboard object is created with the DDEX provider and connection string information and the code accepting the drop uses this information to look up a matching connection.

A designer is typically expected to pass around DDEX provider and connection string information; then, when it needs to use a connection for design time purposes, it calls into the data connection manager to retrieve a connection given the information

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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