一个或多个实体的验证失败。有关详细信息，请参阅“EntityValidationErrors”属性。代码第一 [英] Validation failed for one or more entities. See 'EntityValidationErrors' property for more details. Code First

问题描述

我收到此错误：

Validation failed for one or more entities. See 'EntityValidationErrors' property for more details.

当我尝试使用更新数据库命令在包管理器控制台。

when i try to update the database with the Update-Database command in the Package Manager Console.

如何将线条写入视觉工作室的输出窗口？

How can I write the lines to the output window in visual studio?

我试过：

try
{
    context.SaveChanges();
}
catch (System.Data.Entity.Validation.DbEntityValidationException e)
{
    foreach (var eve in e.EntityValidationErrors)
    {
        System.Diagnostics.Debug.WriteLine("Entity of type \"{0}\" in state \"{1}\" has the following validation errors:",
            eve.Entry.Entity.GetType().Name, eve.Entry.State);
        foreach (var ve in eve.ValidationErrors)
        {
            System.Diagnostics.Debug.WriteLine("- Property: \"{0}\", Error: \"{1}\"",
                ve.PropertyName, ve.ErrorMessage);
        }
    }
    throw;
}

但是没有工作。关于如何调试这些的其他建议？

But that didn't work. Any other suggestions on how to debug this?

推荐答案

我不知道为什么写入VS输出窗口不起作用以及如何使其工作。但是，作为最后的手段，只需将错误写入文本文件，该文本应该独立于您拥有的应用程序的类型：

I don't know why writing to the VS output window doesn't work and how to make it work. But as a last resort just write the errors into a text file which should work independent of the type of application you have:

try
{
    context.SaveChanges();
}
catch (System.Data.Entity.Validation.DbEntityValidationException e)
{
    var outputLines = new List<string>();
    foreach (var eve in e.EntityValidationErrors)
    {
        outputLines.Add(string.Format(
            "{0}: Entity of type \"{1}\" in state \"{2}\" has the following validation errors:",
            DateTime.Now, eve.Entry.Entity.GetType().Name, eve.Entry.State));
        foreach (var ve in eve.ValidationErrors)
        {
            outputLines.Add(string.Format(
                "- Property: \"{0}\", Error: \"{1}\"",
                ve.PropertyName, ve.ErrorMessage));
        }
    }
    //Write to file
    System.IO.File.AppendAllLines(@"c:\temp\errors.txt", outputLines);
    throw;

    // Showing it on screen
    throw new Exception( string.Join(",", outputLines.ToArray()));

}

这篇关于一个或多个实体的验证失败。有关详细信息，请参阅“EntityValidationErrors”属性。代码第一的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！