public static T AppSetting <T>(string key, T defaultValue = default(T)) where T : struct
{
var result = default(T);
var type = typeof(T);
var value = ConfigurationManager.AppSettings[key];
if (type.IsEnum)
{
if (value.IsNumeric())
{
result = SafeClrConvert.ToInt(value).ToEnum(defaultValue);
}
else
{
if (!Enum.TryParse(value, out result))
{
result = defaultValue;
}
}
}
else
{
if (type.IsBasicType())
{
do
{
if (type == TypeHelper.TypeOfBool)
{
result = (T)System.Convert.ChangeType(SafeClrConvert.ToBoolean(value), type);
break;
}
if (type == TypeHelper.TypeOfInt16)
{
result = (T)System.Convert.ChangeType(SafeClrConvert.ToInt16(value), type);
break;
}
if (type == TypeHelper.TypeOfInt32)
{
result = (T)System.Convert.ChangeType(SafeClrConvert.ToInt32(value), type);
break;
}
if (type == TypeHelper.TypeOfInt64)
{
result = (T)System.Convert.ChangeType(SafeClrConvert.ToInt64(value), type);
break;
}
if (type == TypeHelper.TypeOfByte)
{
result = (T)System.Convert.ChangeType(SafeClrConvert.ToByte(value), type);
break;
}
if (type == TypeHelper.TypeOfSByte)
{
result = (T)System.Convert.ChangeType(SafeClrConvert.ToSByte(value), type);
break;
}
if (type == TypeHelper.TypeOfUInt16)
{
result = (T)System.Convert.ChangeType(SafeClrConvert.ToUInt16(value), type);
break;
}
if (type == TypeHelper.TypeOfUInt32)
{
result = (T)System.Convert.ChangeType(SafeClrConvert.ToUInt32(value), type);
break;
}
if (type == TypeHelper.TypeOfUInt64)
{
result = (T)System.Convert.ChangeType(SafeClrConvert.ToUInt64(value), type);
break;
}
if (type == TypeHelper.TypeOfChar)
{
result = (T)System.Convert.ChangeType(SafeClrConvert.ToChar(value), type);
break;
}
if (type == TypeHelper.TypeOfDateTime)
{
result = (T)System.Convert.ChangeType(SafeClrConvert.ToDateTime(value), type);
break;
}
if (type == TypeHelper.TypeOfDecimal)
{
result = (T)System.Convert.ChangeType(SafeClrConvert.ToDecimal(value), type);
break;
}
if (type == TypeHelper.TypeOfDouble)
{
result = (T)System.Convert.ChangeType(SafeClrConvert.ToDouble(value), type);
break;
}
if (type == TypeHelper.TypeOfFloat)
{
result = (T)System.Convert.ChangeType(SafeClrConvert.ToSingle(value), type);
break;
}
if (type == TypeHelper.TypeOfGuid)
{
result = (T)System.Convert.ChangeType(SafeClrConvert.ToGuid(value), type);
break;
}
if (type == TypeHelper.TypeOfTimeSpan)
{
result = (T)System.Convert.ChangeType(SafeClrConvert.ToTimeSpan(value), type);
break;
}
if (type == TypeHelper.TypeOfString)
{
result = (T)((object)value);
break;
}
}while (false);
}
}
return(result);
}