ModelValidationException是未处理的用户code [英] ModelValidationException was unhandled user code

问题描述

您可以帮我下面的错误，我检查一切没有ID错误

ModelValidationException被取消用户code处理

类型'System.Data.Entity.ModelConfiguration.ModelValidationException的异常出现在EntityFramework.dll但在用户code没有处理

更多信息：模型生成过程中检测到一个或多个验证错误：

 公众诠释getCount将（）
    {
        ShoppingCartId = GetCartId（）;        //获取在车中的每个项目的数量和总结起来
        诠释？计数=（从_db.ShoppingCartItems cartItems
                        其中，cartItems.CartId == ShoppingCartId
                        选择（INT？）cartItems.Quantity）.SUM（）;
        //返回0，如果所有的项目都为空
        返回计数？ 0;
    }
 

解决方案

无奈的是.NET并不总是告诉你内部异常。这种抓你的包裹code try块

 赶上（DbEntityValidationException前）{
    //检索错误消息作为字符串列表。
    VAR errorMessages = ex.EntityValidationErrors
            .SelectMany（X =＆GT; x.ValidationErrors）
            。选择（X =＆GT; x.ErrorMessage）;    //加入列表，一个字符串。
    变种fullErrorMessage =的string.join（;，errorMessages）;    //用新合并原来的异常消息。
    VAR exceptionMessage = string.Concat（ex.Message，验证错误是：fullErrorMessage）;    //抛出一个新的DbEntityValidationException与改进的异常信息。
    抛出新DbEntityValidationException（exceptionMessage，ex.EntityValidationErrors）; }
 

Can you help me on the following error, i checked everything no ID mistakes

ModelValidationException was un handled by user code

An exception of type 'System.Data.Entity.ModelConfiguration.ModelValidationException' occurred in EntityFramework.dll but was not handled in user code

Additional information: One or more validation errors were detected during model generation:

 public int GetCount()
    {
        ShoppingCartId = GetCartId();

        // Get the count of each item in the cart and sum them up          
        int? count = (from cartItems in _db.ShoppingCartItems
                        where cartItems.CartId == ShoppingCartId
                        select (int?)cartItems.Quantity).Sum();
        // Return 0 if all entries are null         
        return count ?? 0;
    }

解决方案

Frustratingly .net does not always show you the inner exception. Wrap your code in a try block with this catch

catch (DbEntityValidationException ex) {
    // Retrieve the error messages as a list of strings.
    var errorMessages = ex.EntityValidationErrors
            .SelectMany(x => x.ValidationErrors)
            .Select(x => x.ErrorMessage);

    // Join the list to a single string.
    var fullErrorMessage = string.Join("; ", errorMessages);

    // Combine the original exception message with the new one.
    var exceptionMessage = string.Concat(ex.Message, " The validation errors are: ", fullErrorMessage);

    // Throw a new DbEntityValidationException with the improved exception message.
    throw new DbEntityValidationException(exceptionMessage, ex.EntityValidationErrors); }

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