动态调用textboxfor与反思 [英] Dynamically call textboxfor with reflection

问题描述

什么我试图做的最终结果是通过反射物体动态建立一种形式，它的属性。

The end result of what I am trying to do is build a form dynamically by reflecting an object and it's properties.

我已经创建调用TextBoxFor和CheckBoxFor等方法的HtmlHelper，但现在我需要帮助搞清楚如何将它传递给Html.TextBoxFor

I've created HtmlHelper methods that call TextBoxFor and CheckBoxFor and so on, but now I need help figuring out how to properly reflect the property when passing it to Html.TextBoxFor

下面的辅助方法：

public static MvcHtmlString FormTextBox<TModel>(this HtmlHelper<TModel> helper, String id, String property_name, object model, RouteValueDictionary attributes)
    {          
        Type model_type = model.GetType();

        return helper.TextBoxFor(model_object => model_type.InvokeMember(property_name, BindingFlags.ExactBinding | BindingFlags.GetProperty, null, model, null));
    }

但它打破与此错误code中的回报：

But it breaks on the return with this error code:

模板只能与现场访问，访问属性，一维数组的索引，或单参数自定义索引前pressions使用。

Templates can be used only with field access, property access, single-dimension array index, or single-parameter custom indexer expressions.

基本上我想采取什么会是这样的：

Basically I want to take what would be this:

@Html.TextBoxFor(model => model.Name)

和把它变成这样：

@FormHelpers.FormTextBox("Name", model)

和有它的输出同样的事情。

And have it output the same thing.

更新

我将重申这一点，因为我在解决问题取得了一些进展。

I will restate this, as I have made some progress in solving the problem.

我创建从防爆pression.PropertyOrField防爆pression创建正是我期待的。不过，我不能让TextBoxFor函数接受它。

I've created an Expression from Expression.PropertyOrField that creates exactly what I am looking for. However I can't get the TextBoxFor function to accept it.

Expression fieldExpr = Expression.PropertyOrField(Expression.Constant(model),property_name);

        return helper.TextBoxFor(Expression.Lambda<Func<TModel>>(fieldExpr, null).Compile()());

如何防爆pression正确传递给函数的任何集成开发环境？

Any ides on how to properly pass the Expression to the function?

推荐答案

好吧，我通过使用属性名称和传递的对象的类型建立一个lambda前pression解决了这个问题。我的功能看起来像这样的：

Ok, I solved this problem by building a lambda expression using the property name and the type of the object being passed in. My function looks like this:

ParameterExpression fieldName = Expression.Parameter(typeof(object), property_name);
        Expression fieldExpr = Expression.PropertyOrField(Expression.Constant(model), property_name);
        Expression<Func<TModel, object>> exp = Expression.Lambda<Func<TModel, object>>(fieldExpr, fieldName);

        return helper.TextBoxFor(exp);

例如：

@{ Name myname = new Name();}
@Html.FormTextBox("first", myname)

字段名建立的左侧（第一）的前pression然后fieldExpr建立与类名和属性名前pression的身体。

fieldName builds an expression for the left hand side (first) and then fieldExpr builds the body of the expression with the class name and property name.

EXP最终看起来是这样的：

exp ends up looking like this:

first => value(DynamicForm.Models.Name).first

现在我需要做的就是确保我的数据注释仍正常工作。

Now all I need to do is make sure that my data annotations still work.

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