MVC 代码或模型优先

Question

大多数 MVC 与实体框架的教程都以 Code-First 为中心，您可以在其中编写用于生成模型的类。这提供了控制和迁移的优势，但我认为它缺乏概述。因此，我更愿意使用图形设计器创建模型，但我看不到数据迁移在这种情况下如何或是否工作。看来，当我更改模型（数据库中的数据）时，所有表中的所有数据都被删除。

1. 有没有办法解决这个问题？
2. 使用 Model-First 时如何进行验证？部分课程？

Answer 1

你可以在 mvc 验证旁边使用全局验证 示例：

public class ValidationCriteria
{
    public ValidType Type { get; set; }
    public ValidRange Range { get; set; }
    public ValidFormat Format { get; set; }
    public ValidIsNull IsNull { get; set; }
    public ValidCompare Compare { get; set; }
    public ValidDB DB { get; set; }
    public string Trigger { get; set; }
    public Dictionary<string, ValidationCriteria> Before { get; set; }
    public string After { get; set; }


    public class ValidDB
    {
        public string functionName { get; set; }
        public object[] param { get; set; }
        public object functionClass { get; set; }
        public string msg { get; set; }
        public bool check = false;
    }
    public class ValidCompare
    {
        public string first { get; set; }
        public string second { get; set; }
        public string compareOperator { get; set; }
        public string compareValue { get; set; }
        public string msg { get; set; }
        public bool check = false;


    }
    public ValidationCriteria()
    {
        this.Range = new ValidRange();
        this.Format = new ValidFormat();
        this.IsNull = new ValidIsNull();
        this.Type = new ValidType();
        this.Compare = new ValidCompare();
        this.DB = new ValidDB();

        this.Trigger = "blur";
        this.Before = new Dictionary<string, ValidationCriteria>();
        this.After = "";
    }
    public class ValidType
    {
        // checking element is integer.
        public bool isInt { get; set; }
        // checking element is decimal.
        public bool isDecimal { get; set; }
        public string msg { get; set; }
        public bool check = false;
    }
    public class ValidRange
    {
        public long min { get; set; }
        public long max { get; set; }
        public string msg { get; set; }
        public bool check = false;
    }
    public class ValidFormat
    {
        public bool isEmail { get; set; }
        public string regex { get; set; }
        public string msg { get; set; }
        public bool check = false;
    }

    public class ValidIsNull
    {
        public string nullDefaultVal { get; set; }
        public string msg { get; set; }
        public bool check = false;
    }



}

同时您可以在控制器中使用验证部分 示例：

private bool validateMaintainanceManagement(MaintainanceCRUD.Maintainance model, bool edit = false, bool ServerValidation = true)
    {
        bool ValidModel = false;

        Dictionary<string, ValidationCriteria> validCriteria = new Dictionary<string, ValidationCriteria>();

        #region maintainTitle Criteria

        ValidationCriteria maintainTitle = new ValidationCriteria();

        maintainTitle.IsNull.msg = Resources.Home.ErrmaintainTitle;
        maintainTitle.IsNull.check = true;
        maintainTitle.IsNull.nullDefaultVal = "-1";

        //maintainTitle.Trigger = "change"; // this may trigger if you are using dropdown
        validCriteria.Add("maintainTitle", maintainTitle);
        #endregion