我有一个基础DbContext类喜欢
public abstract class DbContextBase : DbContext
{
public DbContextBase()
{
}
public DbContextBase(DbContextOptions options)
: base(options)
{
}
public override int SaveChanges()
{
this.ValidateEntities();
return base.SaveChanges();
}
public override Task<int> SaveChangesAsync(CancellationToken cancellationToken = default(CancellationToken))
{
this.ValidateEntities();
return base.SaveChangesAsync(cancellationToken);
}
public override Task<int> SaveChangesAsync(bool acceptAllChangesOnSuccess, CancellationToken cancellationToken = default(CancellationToken))
{
this.ValidateEntities();
return base.SaveChangesAsync(acceptAllChangesOnSuccess, cancellationToken);
}
protected virtual void ValidateEntities()
{
var entities = this.ChangeTracker.Entries().
Where(s => s.State == EntityState.Added || s.State == EntityState.Modified);
foreach (var entity in entities)
{
var validationContext = new ValidationContext(entity);
Validator.ValidateObject(entity, validationContext);
}
}
}
我的所有Db Context类都继承自这个基类。问题是，即使存在验证违规，Validator.ValidateObject()行也不会抛出ValidationException。在调试器中，我可以看到该行已执行。例如，对于下面的模型类，我尝试调用SaveChangesAsync()并将Name设置为null，但验证通过：
public class MyModel : IEntity<long>
{
[Key]
public long Id { get; set; }
[Required]
public string Name { get; set; }
}
IEntity<T>只是在所有型号上施加了Id财产。
问题是变量entity不包含实体实例，而是更改跟踪器（EntityEntry）实例，因此代码试图验证错误的东西。
因此要么重命名变量并使用entry.Entity属性：
var entries = this.ChangeTracker.Entries()
.Where(s => s.State == EntityState.Added || s.State == EntityState.Modified);
foreach (var entry in entries)
{
var validationContext = new ValidationContext(entry.Entity);
Validator.ValidateObject(entry.Entity, validationContext);
}
或保持代码不变，但请确保entities变量包含可枚举的实体实例：
var entities = this.ChangeTracker.Entries()
.Where(s => s.State == EntityState.Added || s.State == EntityState.Modified)
.Select(s => s.Entity); // <--
public class MyModel : IEntity<long>
{
[Key]
public long Id { get; set; }
[Required(AllowEmptyStrings = false)]
public string Name { get; set; }
}