DataReaderExtensions.GetBytes(DbDataReader, String, Int64, Byte[], Int32, Int32) 方法

定义

从指定列中指定索引处开始读取指定字节数,并将其写入缓冲区中从指定位置开始的缓冲区。Reads a specified number of bytes from the specified column starting at a specified index and writes them to a buffer starting at a specified position in the buffer.

public:
[System::Runtime::CompilerServices::Extension]
 static long GetBytes(System::Data::Common::DbDataReader ^ reader, System::String ^ name, long dataOffset, cli::array <System::Byte> ^ buffer, int bufferOffset, int length);
public static long GetBytes (this System.Data.Common.DbDataReader reader, string name, long dataOffset, byte[] buffer, int bufferOffset, int length);
static member GetBytes : System.Data.Common.DbDataReader * string * int64 * byte[] * int * int -> int64
<Extension()>
Public Function GetBytes (reader As DbDataReader, name As String, dataOffset As Long, buffer As Byte(), bufferOffset As Integer, length As Integer) As Long

参数

reader
DbDataReader

要从中获取列值的数据读取器。The data reader to get the column value from.

name
String

列的名称。The name of the column.

dataOffset
Int64

行中作为读取操作起始位置的索引。The index within the row from which to begin the read operation.

buffer
Byte[]

要将数据复制到的缓冲区。The buffer into which to copy the data.

bufferOffset
Int32

要将数据复制到的位置的缓冲区索引。The index with the buffer to which the data will be copied.

length
Int32

要读取的最大字符数。The maximum number of characters to read.

返回

Int64

读取的实际字节数。The actual number of bytes read.

例外

指定的名称不是有效的列名。The name specified is not a valid column name.

指定的强制转换无效。The specified cast is not valid.

适用于

另请参阅