VariableDispenser 类

Accesses the Variables collection during package execution. This class cannot be inherited.

继承层次结构

System. . :: . .Object
  Microsoft.SqlServer.Dts.Runtime. . :: . .DtsObject
    Microsoft.SqlServer.Dts.Runtime..::..VariableDispenser

命名空间：  Microsoft.SqlServer.Dts.Runtime
程序集：  Microsoft.SqlServer.ManagedDTS（在 Microsoft.SqlServer.ManagedDTS.dll 中）

语法

声明
Public NotInheritable Class VariableDispenser _
    Inherits DtsObject
用法
Dim instance As VariableDispenser

public sealed class VariableDispenser : DtsObject

public ref class VariableDispenser sealed : public DtsObject

[<SealedAttribute>]
type VariableDispenser =  
    class
        inherit DtsObject
    end

public final class VariableDispenser extends DtsObject

VariableDispenser 类型公开以下成员。

方法

	名称	说明
	Contains	Specifies whether an item can be retrieved from the VariableDispenser collection by using indexing without throwing an exception.
	Equals	Determines whether two object instances are equal. （从 DtsObject 继承。）
	Finalize	（从 Object 继承。）
	GetHashCode	Returns the hash code for this instance. （从 DtsObject 继承。）
	GetQualifiedName	Returns the qualified name of the variable.
	GetType	（从 Object 继承。）
	GetVariables	Locks the variables that are in the read-only list and the read/write list.
	LockForRead	Adds the variable to the list of variables to be locked for read-only access.
	LockForWrite	Adds the variable to the list of variables to be locked for read/write access.
	LockOneForRead	Puts the variable in a list, and then locks it for read-only access.
	LockOneForWrite	Puts the variable in a list, and then locks it for read/write access.
	MemberwiseClone	（从 Object 继承。）
	Reset	Clears both the read-only list and read/write list when the call to GetVariables fails.
	ToString	（从 Object 继承。）

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注释

There are two scenarios for using the variable dispenser.

1. You want just one variable. In this scenario, call LockOneForRead or LockOneForWrite, and a collection with one element is returned.

2. You want several variables. In this scenario, call LockForRead and LockForWrite several times, one for each variable. This builds up two lists, one list that contains variables for reading and one list that contains variables for writing. Next, call GetVariables, which gives you a collection that contains all of the locked variables. If GetVariables succeeds, the two lists, which are the lists of variable names, not actual locks, are cleared.

To explicitly release the locks, call Unlock on the collection. This method unlocks the variables themselves. If GetVariables fails, the lists remain unchanged, and you can call GetVariables again. If you still do not succeed in obtaining the variables, call Reset to clear the lists and bring the variable dispenser back to its initial state.

The Variables collection contains a Locked property that indicates whether a variable dispenser collection of variables is locked (true) or unlocked (false). The reason to review this property is that some tasks explicitly release locks to the variables they are using, and calling Unlock twice throws an error. Therefore, you should use this property to determine whether the dispensed collection is locked before calling Unlock.

重要提示
The VariableDispenser is used with the Runtime classes. If you are using data flow components (Microsoft.SqlServer.Dts.Pipeline), then you may be required to use the IDTSVariableDispenser100 instead. To know which variable dispenser to use, see the documentation for the object you are acquiring variables on, and verify the return object of the method.

线程安全

此类型的任何公共 static（在 Visual Basic 中为 Shared） 成员都是线程安全的。不保证所有实例成员都是线程安全的。

请参阅

参考

Microsoft.SqlServer.Dts.Runtime 命名空间