IFillLockBytes Implementation
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4/8/2010
The system provides an IFillLockBytes implementation as part of its existing implementation of Compound Files.
Downloading code can create an instance of an asynchronous Compound File object by calling StgOpenAsyncDocFileOnIFillLockBytes and can create an instance of an asynchronous byte array wrapper object on an existing file or byte array by calling either the StgGetIFillLockBytesOnFile function or the StgGetIFillLockBytesOnILockBytes function.
When to Use
Currently, URL monikers are the only users of COM's asynchronous storage implementation.
Remarks
The following are the four methods of the IFillLockBytes implementation.
- IFillLockBytes::FillAppend
Writes a new block of bytes to the end of a byte array. The size of the block is specified as a parameter to FillAppend.
- IFillLockBytes::FillAt
Writes a new block of data to a specified location in the bite array.
- IFillLockBytes::SetFillSize
Sets the size of the byte array. Returns E_FAIL from calls to ILockBytes::ReadAt that attempt to access data beyond the upper limit specified by the method.
- IFillLockBytes::Terminate
Informs the byte array that a download has been terminated either successfully or unsuccessfully.
To determine whether the platform supports this interface, see Determining Supported COM APIs.