แก้ไข

แชร์ผ่าน


OracleBFile.Seek(Int64, SeekOrigin) Method

Definition

Sets the position on the current OracleBFile stream.

public:
 override long Seek(long offset, System::IO::SeekOrigin origin);
public override long Seek (long offset, System.IO.SeekOrigin origin);
override this.Seek : int64 * System.IO.SeekOrigin -> int64
Public Overrides Function Seek (offset As Long, origin As SeekOrigin) As Long

Parameters

offset
Int64

A byte offset relative to origin. If offset is negative, the new position will precede the position specified by origin by the number of bytes specified by offset. If offset is zero, the new position will be the position specified by origin. If offset is positive, the new position will follow the position specified by origin by the number of bytes specified by offset.

origin
SeekOrigin

A value of type System.IO.SeekOrigin indicating the reference point used to obtain the new position.

Returns

The new position within the current stream.

Exceptions

Attempted to set a position with a negative value or greater than the length of the stream.

Methods were called after the stream was closed or disposed.

Remarks

If offset is negative, the new position is required to precede the position specified by origin by the number of bytes specified by offset. If offset is zero, the new position is required to be the position specified by origin. If offset is positive, the new position is required to follow the position specified by origin by the number of bytes specified by offset.

Seeking to any location beyond the length of the stream is not supported.

Any attempt to access a closed OracleBFile using the Read or Seek methods reopens an OracleBFile stream automatically.

The following C# example assumes this schema in an Oracle table:

(col1 number, col2 BFILE)  

The example demonstrates using the Read and Seek methods to access an OracleBFile object.

byte[] buffer = new byte[100];  
OracleDataReader dataReader = command.ExecuteReader();  
using (dataReader) {  
    if (dataReader.Read()) {  
            OracleBFile BFile = dataReader.GetOracleBFile(1);  
        using (BFile) {  
            BFile.Seek(0, SeekOrigin.Begin);  
            BFile.Read(buffer, 0, 100);  
        }  
    }  
}  

Applies to