SqlDataReader.GetDouble(Int32) 方法
定义
获取作为双精度浮点数的指定列的值。Gets the value of the specified column as a double-precision floating point number.
public:
override double GetDouble(int i);
public:
virtual double GetDouble(int i);
public override double GetDouble (int i);
public double GetDouble (int i);
override this.GetDouble : int -> double
abstract member GetDouble : int -> double
override this.GetDouble : int -> double
Public Overrides Function GetDouble (i As Integer) As Double
Public Function GetDouble (i As Integer) As Double
参数
- i
- 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.
实现
例外
指定的强制转换无效。The specified cast is not valid.
注解
不执行任何转换。No conversions are performed. 因此,检索的数据必须已经是双精度浮点数。Therefore, the data retrieved must already be a double-precision floating point number.
调用 IsDBNull 以在调用此方法前检查是否有 null 值。Call IsDBNull to check for null values before calling this method.