泛型摘录
一段类型转化
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/// <summary>
/// Gets the value.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="columnName">Name of the column.</param>
/// <returns></returns>
public T GetValue<T>(string columnName)
{
columnName = columnName.ToLowerInvariant();
object oVal;
try
{
oVal = this[columnName].CurrentValue;
}
catch
{
throw new ArgumentException("There's no column called '" + columnName + "' for this object", "columnName");
}
if(oVal == null || oVal == DBNull.Value)
return default(T);
Type type = typeof(T);
if(type == typeof(object))
return (T)oVal;
// handle nullable type conversion
if(IsNullable(type))
{
NullableConverter converter = new NullableConverter(type);
type = converter.UnderlyingType;
}
//if (IsNullable(type) || type == typeof(object))
//{
// if (type == typeof(bool?))
// return (T)(object)Convert.ToBoolean(oVal);
// return (T)oVal;
//}
//if (type == typeof(Guid))
// return (T)(object)new Guid(oVal.ToString());
Type valType = oVal.GetType();
if(valType == typeof(Byte[]))
return (T)Convert.ChangeType(oVal, valType);
return (T)Convert.ChangeType(oVal, type);
}