OleDbDataReader.GetDouble(Int32) 方法

定义

获取指定列的双精度浮点数形式的值。Gets the value of the specified column as a double-precision floating-point number.

public:
 virtual double GetDouble(int ordinal);
public double GetDouble (int ordinal);
override this.GetDouble : int -> double
Public Function GetDouble (ordinal As Integer) As Double

参数

ordinal
Int32

从零开始的列序号。The zero-based column ordinal.

返回

指定列的值。The value of the specified column.

异常

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

注解

不执行任何转换;因此,检索的数据必须已经是双精度浮点数。No conversions are performed; therefore, the data retrieved must already be a double-precision floating-point number.

调用IsDBNull此方法之前,调用以查找 null 值。Call IsDBNull to look for null values before calling this method.

适用于

另请参阅