自定义Remote验证，对博客园文章“Asp.net MVC验证哪些事？
最近拜读了博客园我一直很敬仰的大神几年前关于asp.net mvc中自定义Remote验证的文章：
Asp.net MVC验证哪些事（3）-- Remote验证及其改进(附源码)
获益匪浅。但是文中给出的解决方案，个人觉得里面动态执行验证方法的那段代码有可以完善的地方(并没有半点对大神的诋毁，代码为下面标色部分)：
public class CustomModelBinder : DefaultModelBinder
{
protected override void BindProperty(ControllerContext controllerContext,
ModelBindingContext bindingContext,
PropertyDescriptor propertyDescriptor)
{
if (propertyDescriptor.PropertyType == typeof(string))
{
//检查Model绑定的属性中，是否应用了CustomRemoteAttribute
var remoteAttribute =
propertyDescriptor.Attributes.OfType<CustomRemoteAttribute>()
.FirstOrDefault();
if (remoteAttribute != null)
{
//如果使用了CustomRemoteAttribute, 就开始找到CustomAttribute中指定的Controller
var allControllers = GetControllerNames();
var controllerType = allControllers.FirstOrDefault(x => x.Name ==
remoteAttribute.Controller + "Controller");
if (controllerType != null)
{
//查找Controller中的Action方法
var methodInfo = controllerType.GetMethod(remoteAttribute.Action);
if (methodInfo != null)
{
//调用方法，得到验证的返回结果
bool isValidate = callRemoteValidationFunction(
controllerContext,
bindingContext,
propertyDescriptor,
controllerType,
methodInfo,
remoteAttribute.AdditionalFields);
//如果验证失败，添加ModelError
if (!isValidate)
{
bindingContext.ModelState.AddModelError(propertyDescriptor.Name, remoteAttribute.ErrorMessage);
}
}
}
}
}
base.BindProperty(controllerContext, bindingContext, propertyDescriptor);
}
/// This function calls the indicated method on a new instance of the supplied
/// controller type and return the error string. (NULL if not)
private bool callRemoteValidationFunction(
ControllerContext controllerContext,
ModelBindingContext bindingContext,
MemberDescriptor propertyDescriptor,
Type controllerType,
MethodInfo methodInfo,
string additionalFields)
{
var propertyValue = controllerContext.RequestContext.HttpContext.Request.Form[
bindingContext.ModelName + propertyDescriptor.Name];
var controller = (Controller)Activator.CreateInstance(controllerType);
object result = null;
var parameters = methodInfo.GetParameters();
if (parameters.Length == 0)
{
result = methodInfo.Invoke(controller, null);
}
else
{
var parametersArray = new List<object>();
if (!string.IsNullOrEmpty(additionalFields))
{
int i = 0;
foreach (var field in additionalFields.Split(','))
{
//可以根据参数名字对应，这里根据参数顺序对应
string value = controllerContext.RequestContext.HttpContext
.Request.Form[bindingContext.ModelName + field];
parametersArray.Add(Convert.ChangeType(value, parameters[i].ParameterType));
i++;
}
if (parametersArray.Count == parameters.Length)
{
result = methodInfo.Invoke(controller, parametersArray.ToArray());
}
}
}
if (result != null)
{
return Convert.ToBoolean(((JsonResult)result).Data);
}
return false; ;
}
/// Returns a list of all Controller types
private static IEnumerable<Type> GetControllerNames()
{
var controllerNames = new List<Type>();
GetSubClasses<Controller>().ForEach(controllerNames.Add);
return controllerNames;
}
private static List<Type> GetSubClasses<T>()
{
return Assembly.GetCallingAssembly().GetTypes().Where(
type => type.IsSubclassOf(typeof(T))).ToList();
}
}当然这段代码是没有任何问题的，也考虑到了验证方法包含多个参数的问题，但是有个问题就是：Remote验证方法的参数都被指定成了string类型，但是实际中，我们不能保证我们的验证方法的参数都是string类型。这里给出自己改进的代码部分
var parametersArray = new List<object>();
if (!string.IsNullOrEmpty(additionalFields))
{
int i = 0;
foreach (var field in additionalFields.Split(','))
{
//可以根据参数名字对应，这里根据参数顺序对应
string value = controllerContext.RequestContext.HttpContext
.Request.Form[bindingContext.ModelName + field];
parametersArray.Add(Convert.ChangeType(value, parameters[i].ParameterType));
i++;
}
if (parametersArray.Count == parameters.Length)
{
result = methodInfo.Invoke(controller, parametersArray.ToArray());
}
}
上面是根据验证参数顺序来对应的，当然，你也可以根据参数名称来对应了。下面是调用方法：
[Required]
[CustomRemote("CheckMMSRecord", "MMSRecord", AdditionalFields = "CustPhone,Type,VCode", ErrorMessage = "请输入正确的手机验证码")]
public string VCode { get; set; }
验证方法定义为：
public JsonResult CheckMMSRecord2(string Mobile, int Type, string VCode)
CustomModelBinder完整如下：
public class CustomModelBinder : DefaultModelBinder
{
protected override void BindProperty(ControllerContext controllerContext,
ModelBindingContext bindingContext,
PropertyDescriptor propertyDescriptor)
{
if (propertyDescriptor.PropertyType == typeof(string))
{
//检查Model绑定的属性中，是否应用了CustomRemoteAttribute
var remoteAttribute =
propertyDescriptor.Attributes.OfType<CustomRemoteAttribute>()
.FirstOrDefault();
if (remoteAttribute != null)
{
//如果使用了CustomRemoteAttribute, 就开始找到CustomAttribute中指定的Controller
var allControllers = GetControllerNames();
var controllerType = allControllers.FirstOrDefault(x => x.Name ==
remoteAttribute.Controller + "Controller");
if (controllerType != null)
{
//查找Controller中的Action方法
var methodInfo = controllerType.GetMethod(remoteAttribute.Action);
if (methodInfo != null)
{
//调用方法，得到验证的返回结果
bool isValidate = callRemoteValidationFunction(
controllerContext,
bindingContext,
propertyDescriptor,
controllerType,
methodInfo,
remoteAttribute.AdditionalFields);
//如果验证失败，添加ModelError
if (!isValidate)
{
bindingContext.ModelState.AddModelError(propertyDescriptor.Name, remoteAttribute.ErrorMessage);
}
}
}
}
}
base.BindProperty(controllerContext, bindingContext, propertyDescriptor);
}
/// This function calls the indicated method on a new instance of the supplied
/// controller type and return the error string. (NULL if not)
private bool callRemoteValidationFunction(
ControllerContext controllerContext,
ModelBindingContext bindingContext,
MemberDescriptor propertyDescriptor,
Type controllerType,
MethodInfo methodInfo,
string additionalFields)
{
var propertyValue = controllerContext.RequestContext.HttpContext.Request.Form[
bindingContext.ModelName + propertyDescriptor.Name];
var controller = (Controller)Activator.CreateInstance(controllerType);
object result = null;
var parameters = methodInfo.GetParameters();
if (parameters.Length == 0)
{
result = methodInfo.Invoke(controller, null);
}
else
{
var parametersArray = new List<object>();
if (!string.IsNullOrEmpty(additionalFields))
{
int i = 0;
foreach (var field in additionalFields.Split(','))
{
//可以根据参数名字对应，这里根据参数顺序对应
string value = controllerContext.RequestContext.HttpContext
.Request.Form[bindingContext.ModelName + field];
parametersArray.Add(Convert.ChangeType(value, parameters[i].ParameterType));
i++;
}
if (parametersArray.Count == parameters.Length)
{
result = methodInfo.Invoke(controller, parametersArray.ToArray());
}
}
}
if (result != null)
{
return Convert.ToBoolean(((JsonResult)result).Data);
}
return false; ;
}
/// Returns a list of all Controller types
private static IEnumerable<Type> GetControllerNames()
{
var controllerNames = new List<Type>();
GetSubClasses<Controller>().ForEach(controllerNames.Add);
return controllerNames;
}
private static List<Type> GetSubClasses<T>()
{
return Assembly.GetCallingAssembly().GetTypes().Where(
type => type.IsSubclassOf(typeof(T))).ToList();
}
}
以上仅为个人遇见，有不对之处，还望斧正。