/// <summary>

/// 数据类型转换

/// </summary>

/// <typeparam name="T">类型</typeparam>

/// <param name="value">源数据</param>

/// <param name="defaultValue">默认值</param>

/// <returns>结果</returns>

public static T To<T>(object value, T defaultValue)

{

/* T obj;

try {

if (value == null) {

return defaultValue;

}

obj = (T)Convert.ChangeType(value, typeof(T));

if (obj == null) {

obj = defaultValue;

}

} catch {

obj = defaultValue;

}

return obj;*/

T obj = default(T);

try

{

if (value == null)

{

return defaultValue;

}

var valueType = value.GetType();

var targetType = typeof(T);

tag1:

if (valueType == targetType)

{

return (T)value;

}

if (targetType.IsEnum)

{

if (value is string)

{

return (T)System.Enum.Parse(targetType, value as string);

}

else

{

return (T)System.Enum.ToObject(targetType, value);

}

}

if (targetType == typeof(Guid) && value is string)

{

object obj1 = new Guid(value as string);

return (T)obj1;

}

if (targetType == typeof(DateTime) && value is string)

{

DateTime d1;

if (DateTime.TryParse(value as string, out d1))

{

object obj1 = d1;

return (T)obj1;

}

}

if (targetType.IsGenericType)

{

if (targetType.GetGenericTypeDefinition() == typeof(Nullable<>))

{

targetType = Nullable.GetUnderlyingType(targetType);

goto tag1;

}

}

if (value is IConvertible)

{

obj = (T)Convert.ChangeType(value, typeof(T));

}

if (obj == null)

{

obj = defaultValue;

}

}

catch

{

obj = defaultValue;

}

return obj;

}