asp.net MVC 1.0和2.0货币模型绑定
-
20-09-2019 - |
题
我想创建模型绑定功能,因此用户可以输入“”“”。等,为结合到我的视图模型的一个双精度值的货币值。
我能够通过创建自定义模型粘合剂为此在MVC 1.0,然而由于升级到MVC 2.0此功能不再有效。
有没有人必须执行此功能的任何想法或更好的解决方案?一个更好的解决办法是使用一些数据注解或自定义属性。
public class MyViewModel
{
public double MyCurrencyValue { get; set; }
}
一个优选的解决方案将是这样的事情...
public class MyViewModel
{
[CurrencyAttribute]
public double MyCurrencyValue { get; set; }
}
下面是我的模型溶液在MVC 1.0结合。
public class MyCustomModelBinder : DefaultModelBinder
{
public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
object result = null;
ValueProviderResult valueResult;
bindingContext.ValueProvider.TryGetValue(bindingContext.ModelName, out valueResult);
bindingContext.ModelState.SetModelValue(bindingContext.ModelName, valueResult);
if (bindingContext.ModelType == typeof(double))
{
string modelName = bindingContext.ModelName;
string attemptedValue = bindingContext.ValueProvider[modelName].AttemptedValue;
string wantedSeperator = NumberFormatInfo.CurrentInfo.NumberDecimalSeparator;
string alternateSeperator = (wantedSeperator == "," ? "." : ",");
try
{
result = double.Parse(attemptedValue, NumberStyles.Any);
}
catch (FormatException e)
{
bindingContext.ModelState.AddModelError(modelName, e);
}
}
else
{
result = base.BindModel(controllerContext, bindingContext);
}
return result;
}
}
解决方案
您可以尝试在电线之间的东西:
// Just a marker attribute
public class CurrencyAttribute : Attribute
{
}
public class MyViewModel
{
[Currency]
public double MyCurrencyValue { get; set; }
}
public class CurrencyBinder : DefaultModelBinder
{
protected override object GetPropertyValue(
ControllerContext controllerContext,
ModelBindingContext bindingContext,
PropertyDescriptor propertyDescriptor,
IModelBinder propertyBinder)
{
var currencyAttribute = propertyDescriptor.Attributes[typeof(CurrencyAttribute)];
// Check if the property has the marker attribute
if (currencyAttribute != null)
{
// TODO: improve this to handle prefixes:
var attemptedValue = bindingContext.ValueProvider
.GetValue(propertyDescriptor.Name).AttemptedValue;
return SomeMagicMethodThatParsesTheAttemptedValue(attemtedValue);
}
return base.GetPropertyValue(
controllerContext,
bindingContext, propertyDescriptor,
propertyBinder
);
}
}
public class HomeController: Controller
{
[HttpPost]
public ActionResult Index([ModelBinder(typeof(CurrencyBinder))] MyViewModel model)
{
return View();
}
}
更新:
这里的粘合剂的改进(见前面的代码TODO
节):
if (!string.IsNullOrEmpty(bindingContext.ModelName))
{
var attemptedValue = bindingContext.ValueProvider
.GetValue(bindingContext.ModelName).AttemptedValue;
return SomeMagicMethodThatParsesTheAttemptedValue(attemtedValue);
}
为了处理收集你需要注册在Application_Start
粘结剂,你将不再能装饰与ModelBinderAttribute
名单:
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
RegisterRoutes(RouteTable.Routes);
ModelBinders.Binders.Add(typeof(MyViewModel), new CurrencyBinder());
}
然后你的行动看起来是这样的:
[HttpPost]
public ActionResult Index(IList<MyViewModel> model)
{
return View();
}
总结重要的部分:
bindingContext.ValueProvider.GetValue(bindingContext.ModelName)
此粘合剂的进一步改善的步骤将是处理验证(AddModelError / SetModelValue)
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