技术总结---项目开端【基础设施制造--造轮子 自动生成sql +导入封装】

因为这个项目没有使用框架，使用了sqlite数据库。后面的业务可想而知会使用多少拼接sql，这就会至关麻烦 一旦数据库改变 就要改不少东西。

因此基础的就是封装生成sql。须要使用反射和自定义的特性。 自定义特性在于“绑定数据库列名”和“绑定业务格式”

1、业务一---自动生成sql
1.首先是实体对应的表:[特性--》TableNameAttr]
using System;
using System.Collections.Generic;
using System.Text;

namespace PublicLibrary.attr
{

//数据库表名
[AttributeUsage(AttributeTargets.Class, AllowMultiple = true)]
public class TableNameAttr: Attribute{
    string value;

    public TableNameAttr(string value)
    {
        this.Value = value;
    }

    public string Value { get => value; set => this.value = value; }
}

}
2.其次是实体字段对应的列名:[特性--》TableFieldAttr]
using System;

namespace PublicLibrary.attr
{

//查询 新增 修改的注解
[AttributeUsage(AttributeTargets.Field, AllowMultiple = true)]
public class TableFieldAttr:Attribute
{
    //bool是boolean 的类型
    //是否存在的字段==> 针对查询
    private bool isExist =true;

    //数据库列名
    private string columName;


    //字符串类型
    private string jdbcType;

    //默认值
    private string value;

/* //新增 修改 选着性操做的字段

private bool selective;*/

    //须要自定义的数据库函数
    private bool definedFunc;

    //是否主键
    private bool primaryKey =false;


    //函数的表达式
    private string patternStr;

    //是否更新 默认为true
    private bool isUpdate =true;


    public TableFieldAttr(string columName)
    {
        this.ColumName = columName;
    }

    //字段数据库不存在
    public TableFieldAttr(bool isExist)
    {
        this.IsExist = false;
    }

    //行数据列名 默认值
    public TableFieldAttr(string columName, string value)
    {
        this.ColumName = columName;
        this.Value = value;
    }

    
    public TableFieldAttr(string columName, string value, string jdbcType,bool definedFunc, bool primaryKey, string patternStr)
    {
        this.ColumName = columName;
        this.DefinedFunc = definedFunc;
        this.JdbcType = jdbcType;
        this.DefinedFunc = definedFunc;
        this.PrimaryKey = primaryKey;
        this.PatternStr = patternStr;
        this.Value = value;
    }   
    
    public TableFieldAttr(string columName, string value, string jdbcType,bool definedFunc, bool primaryKey, string patternStr,bool isUpdate)
    {
        this.ColumName = columName;
        this.DefinedFunc = definedFunc;
        this.JdbcType = jdbcType;
        this.DefinedFunc = definedFunc;
        this.PrimaryKey = primaryKey;
        this.PatternStr = patternStr;
        this.Value = value;
        this.IsUpdate = isUpdate;
    }
  

    public bool IsExist { get => isExist; set => isExist = value; }
    public string ColumName { get => columName; set => columName = value; }
    public string JdbcType { get => jdbcType; set => jdbcType = value; }
    public string Value { get => value; set => this.value = value; }
    public bool DefinedFunc { get => definedFunc; set => definedFunc = value; }
    public bool PrimaryKey { get => primaryKey; set => primaryKey = value; }
    public string PatternStr { get => patternStr; set => patternStr = value; }
    public bool IsUpdate { get => isUpdate; set => isUpdate = value; }
}

}
3.再就是建立sql的公共方法:
using System;
using System.Collections.Generic;
using System.Reflection;
using System.Text;
using PublicLibrary.attr;
using PublicLibrary.serivce;
using PublicLibrary.serivce.impl;

namespace PublicLibrary
{

public  static class SQLiteSqlUtils
{

    /// <summary>
    /// 建立 查询语句
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="t">对象</param>
    /// <param name="whereColums">查询出的字段,如[id,name]</param>
    /// <returns></returns>
    public static string CreateSelectSql<T>(T t,string[] whereColums)
    {
        Type type = typeof(T);
        BindingFlags bindingFlags = BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic;
        var startTime = DateTime.Now;
        TableNameAttr tableAttr = type.GetCustomAttribute<TableNameAttr>();
        string tableName = tableAttr != null ? tableAttr.Value : "";

        string sqlTemp = "SELECT #{colums} FROM " + tableName + " WHERE 1=1 #{whereColums}";

        Dictionary<string, TableFieldAttr> fieldAttrDic = new Dictionary<string, TableFieldAttr>();

        StringBuilder colums = new StringBuilder();

        StringBuilder whereColumsTem = new StringBuilder("");

        FieldInfo[] fieldInfos = type.GetFields(bindingFlags);

        PropertyInfo propertyInfo  = null;

        int countFlag = 0;
        IEnumerable<TableFieldAttr> enumerable = null;

        for (int i = 0; i < fieldInfos.Length; i++)
        {
            enumerable = fieldInfos[i].GetCustomAttributes<TableFieldAttr>();

            foreach (TableFieldAttr attr in enumerable){
                //不是主键 和是数据库字段
                if (attr.IsExist)
                {
                    fieldAttrDic.Add(fieldInfos[i].Name, attr);
                    colums.Append((countFlag == 0 ? "" : ",") + attr.ColumName);
                    countFlag++;
                }
            }
          
        }

        countFlag = 0;
        TableFieldAttr fieldAttr = null;
        if (whereColums != null)
        {
            for (int k = 0; k < whereColums.Length; k++)
            {
                propertyInfo = type.GetProperty(UpperCaseFirst(whereColums[k]), bindingFlags);
                if (propertyInfo != null)
                {
                    fieldAttr = fieldAttrDic[whereColums[k]];
                    whereColumsTem.Append(" and " + (fieldAttr == null ? "NoField" : fieldAttr.ColumName) + "='" + propertyInfo.GetValue(t) + "'");
                    /*whereColumsTem.Append((countFlag == 0 ? " " : " and ") + tableName + "." + (fieldAttr == null ? "NoField" : fieldAttr.ColumName) + "='" + propertyInfo.GetValue(t) + "'");
                    countFlag++;*/
                }

            }
        }
     

        string selectSql = sqlTemp.Replace("#{colums}", colums.ToString()).Replace("#{whereColums}", whereColumsTem.ToString());

        return selectSql;
    }


    /// <summary>
    /// 建立 删除语句
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="t">对象</param>
    /// <param name="whereColums">查询出的字段,如[id,name]</param>
    /// <returns></returns>
    public static string CreateDeleteSql<T>(T t, string[] whereColums)
    {
        Dictionary<string, TableFieldAttr> fieldAttrDic = new Dictionary<string, TableFieldAttr>();
        Type type = typeof(T);
        BindingFlags bindingFlags = BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic;
        var startTime = DateTime.Now;
        TableNameAttr tableAttr = type.GetCustomAttribute<TableNameAttr>();
        string tableName = tableAttr != null ? tableAttr.Value : "";

        string sqlTemp = "DELETE FROM " + tableName + " WHERE 1=1 #{whereColums}";

        StringBuilder whereColumsTem = new StringBuilder("");

        FieldInfo[] fieldInfos = type.GetFields(bindingFlags);

        PropertyInfo propertyInfo = null;

        IEnumerable<TableFieldAttr> enumerable = null;

        int countFlag = 0;

        for (int i = 0; i < fieldInfos.Length; i++){
            enumerable = fieldInfos[i].GetCustomAttributes<TableFieldAttr>();

            foreach (TableFieldAttr attr in enumerable){
                //不是主键 和是数据库字段
                if (attr.IsExist){
                    fieldAttrDic.Add(fieldInfos[i].Name, attr);
                }
            }
        }

        TableFieldAttr fieldAttr = null;
        if (whereColums != null)
        {
            for (int k = 0; k < whereColums.Length; k++)
            {
                propertyInfo = type.GetProperty(UpperCaseFirst(whereColums[k]), bindingFlags);
                if (propertyInfo != null)
                {
                    fieldAttr = fieldAttrDic[whereColums[k]];
                    whereColumsTem.Append(" and " + (fieldAttr == null ? "NoField" : fieldAttr.ColumName) + "='" + propertyInfo.GetValue(t) + "'");
                }

            }
        }

        string deleteSql = sqlTemp.Replace("#{whereColums}", whereColumsTem.ToString());
        return deleteSql;
    }

    public static string CreateInsertSql<T>(T t){
        List<T> list = new List<T>();
        list.Add(t);
        return CreateInsertSql<T>( list, new ColumServiceImpl());

    }

    public static string CreateInsertSql<T>(T t, ColumService columService){
        List<T> list = new List<T>();
        list.Add(t);
        return CreateInsertSql<T>(list, columService);

    }

    public static string CreateInsertSql<T>( List<T> list)
    {
        return CreateInsertSql<T>(list, new ColumServiceImpl());

    }

    //新增 批量新增的sql
    public static string CreateInsertSql<T>(List<T> list,ColumService columService)
    {
        Type type = typeof(T);
        BindingFlags bindingFlags = BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic;
        var startTime = DateTime.Now;
        TableNameAttr tableAttr = type.GetCustomAttribute<TableNameAttr>();
        string tableName = tableAttr != null ? tableAttr.Value : "";


        string insertHead = "INSERT INTO " + tableName + "(#{colums}) VALUES\n";
        string valuesTemp = "(#{values})";


        FieldInfo[] fieldInfos = type.GetFields(bindingFlags);

        Dictionary<string, TableFieldAttr> table = new Dictionary<string, TableFieldAttr>();

        Dictionary<string, PropertyInfo> tablePropertys = new Dictionary<string, PropertyInfo>();

        //string iteminfo = "";
        PropertyInfo propertyinfo = null;

        TableFieldAttr tableFieldAttr = null;

        IEnumerable<TableFieldAttr> enumerable = null;

        string columsTemplet = "";
        string valuesTemplet = "";

        for (int i = 0; i < fieldInfos.Length; i++)
        {
            tablePropertys.Add(fieldInfos[i].Name, type.GetProperty(UpperCaseFirst(fieldInfos[i].Name), bindingFlags));
            enumerable = fieldInfos[i].GetCustomAttributes<TableFieldAttr>();

            foreach (TableFieldAttr attr in enumerable)
            {
                table.Add(fieldInfos[i].Name, attr);
                attr.JdbcType = fieldInfos[i].FieldType.ToString();
                //不是主键 和是数据库字段
                if (attr.IsExist)
                {
                    columsTemplet += " " + attr.ColumName + " ,";
                    valuesTemplet += " #{" + fieldInfos[i].Name + "} ,";
                }
            }
        }

        insertHead = insertHead.Replace("#{colums}", columsTemplet.Substring(0, columsTemplet.Length - 1));

        valuesTemp = valuesTemp.Replace("#{values}", valuesTemplet.Substring(0, valuesTemplet.Length - 1));

        string valuesInfo = "";
        string setValue = "";
        for (int k = 0; k < list.Count; k++)
        {

            object value = "";
            string currentValue = "";
            string rowInfo = valuesTemp;
            //rowInfo = ;
            foreach (string key in table.Keys)
            {
                propertyinfo = tablePropertys[key];

                tableFieldAttr = table[key];
                //默认值 不进行函数转换
                if (tableFieldAttr.Value != null)
                {
                    value = tableFieldAttr.Value;
                    currentValue = value.ToString();
                    setValue =  currentValue;
                }
                else if (propertyinfo != null)
                {
                    value = tablePropertys[key].GetValue(list[k], null);
                    currentValue = (value == null) ? "''" : "'" + value.ToString() + "'";
                    setValue = tableFieldAttr.DefinedFunc ? columService.DoFormat(key, currentValue, tableFieldAttr.PatternStr) : currentValue;
                }

                
                rowInfo = rowInfo.Replace("#{" + key + "}", setValue);
            }

            valuesInfo += rowInfo + ",";

        }

        var endTime = DateTime.Now;
        TimeSpan ts = endTime.Subtract(startTime);
        Console.WriteLine("insert语句生成耗时{0}ms.", ts.TotalMilliseconds);

        return insertHead + valuesInfo.Substring(0, valuesInfo.Length - 1);
    }

    /// <summary>
    ///  单条数据更新
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="t"></param>
    /// <param name="whereColums"></param>
    /// <returns></returns>
    public static string CreateUpdateSql<T>(T t, string[] whereColums)
    {
        List<T> list = new List<T>();
        list.Add(t);
        return CreateUpdateSql<T>(list, whereColums, new ColumServiceImpl());
    }


    /// <summary>
    ///  更新的语句
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="t"></param>
    /// <param name="whereColums">whereColums 必填  参考 新增和修改【id,name】</param>
    /// <param name="columService"></param>
    /// <returns></returns>
    public static string CreateUpdateSql<T>(T t, string[] whereColums, ColumService columService){
        List<T> list = new List<T>();
        list.Add(t);
        return CreateUpdateSql<T>( list, whereColums, columService);
    }

    /// <summary>
    /// 多条数据更新
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="list"></param>
    /// <param name="whereColums"></param>
    /// <returns></returns>
    public static string CreateUpdateSql<T>(List<T> list, string[] whereColums)
    {
        return CreateUpdateSql<T>(list, whereColums, new ColumServiceImpl());
    }

 
    /// <summary>
    /// 修改 批量修改的sql  主语法
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="list"></param>
    /// <param name="whereColums"></param>
    /// <param name="columService"></param>
    /// <returns></returns>
    public static string CreateUpdateSql<T>(List<T> list, string[] whereColums, ColumService columService)
    {
        StringBuilder whereColumsTem = new StringBuilder("");
        List<string> whereColumTs = new List<string>();
        if (whereColums != null)
        {
            whereColumTs = new List<string>(whereColums);
        }

        var startTime = DateTime.Now;
        BindingFlags bindingFlags = BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic;
        Type type = typeof(T);

        TableNameAttr tableAttr = type.GetCustomAttribute<TableNameAttr>();
        string tableName = tableAttr != null ? tableAttr.Value : "";

        string updateSql = "";

        string updateHead = "UPDATE " + tableName + " #{colums} ";


        FieldInfo[] fieldInfos = type.GetFields(bindingFlags);

        Dictionary<string, TableFieldAttr> table = new Dictionary<string, TableFieldAttr>();

        Dictionary<string, PropertyInfo> tablePropertys = new Dictionary<string, PropertyInfo>();

        PropertyInfo propertyinfo = null;

        TableFieldAttr tableFieldAttr = null;
        IEnumerable<TableFieldAttr> enumerable = null;

     

        string setTemplet = "";
        for (int i = 0; i < fieldInfos.Length; i++)
        {
            tablePropertys.Add(fieldInfos[i].Name, type.GetProperty(UpperCaseFirst(fieldInfos[i].Name), bindingFlags));
            enumerable = fieldInfos[i].GetCustomAttributes<TableFieldAttr>();

            foreach (TableFieldAttr attr in enumerable)
            {
                table.Add(fieldInfos[i].Name, attr);
                attr.JdbcType = fieldInfos[i].FieldType.ToString();
                //不是主键 和是数据库字段
                if (attr.IsExist && !attr.PrimaryKey && attr.IsUpdate)
                {
                    setTemplet += " " + attr.ColumName + "= #{" + fieldInfos[i].Name + "} ,";
                }

                //匹配
                if (whereColumTs.Contains(fieldInfos[i].Name))
                {
                    whereColumsTem.Append(" AND " + attr.ColumName + " = #{"+ fieldInfos[i].Name + "}");
                }

            }
        }
        setTemplet = "set " + setTemplet.Substring(0, setTemplet.Length - 1);



        if (whereColumTs.Count>0){
            setTemplet += " WHERE 1=1 " + whereColumsTem.ToString();
        }

        //updateHead += setTemplet;

        string colum = "";
        object value = "";
        string currentValue = "";
        for (int k = 0; k < list.Count; k++)
        {
            colum = setTemplet;

            foreach (string key in table.Keys){
                propertyinfo = tablePropertys[key];

                tableFieldAttr = table[key];
                
                if (tableFieldAttr.Value != null)
                {
                    value = tableFieldAttr.Value;
                    //默认值不作函数处理
                    currentValue = value.ToString();
                } else if (propertyinfo != null){
                    value = tablePropertys[key].GetValue(list[k], null);
                    currentValue = (value == null) ? "''" : "'" + value.ToString() + "'";
                    //实际值才会作函数处理
                    currentValue = tableFieldAttr.DefinedFunc ? columService.DoFormat(key, currentValue, tableFieldAttr.PatternStr) : currentValue;
                }
                else{
                    currentValue = "''";
                }
                colum = colum.Replace("#{" + key + "}", currentValue);

            }
            updateSql += updateHead.Replace("#{colums}", colum) + "\n;";
        }
        updateSql = updateSql.Substring(0, updateSql.Length - 1);

        var endTime = DateTime.Now;
        TimeSpan ts = endTime.Subtract(startTime);
        Console.WriteLine("update语句生成耗时{0}ms.", ts.TotalMilliseconds);

        return updateSql;
    }

    /// <summary>
    ///  首字母大写
    /// </summary>
    /// <param name="str"></param>
    /// <returns></returns>
    public static string UpperCaseFirst(this string str)
    {
        if (string.IsNullOrWhiteSpace(str))
            return string.Empty;
        char[] s = str.ToCharArray();
        char c = s[0];
        if ('a' <= c && c <= 'z')
            c = (char)(c & ~0x20);
        s[0] = c;

        return new string(s);
    }
}

}

实际使用
针对实体：

方法调用示例:
List<OsZbSupplierProductInfo> record =new List<OsZbSupplierProductInfo>();

SQLiteSqlUtils.CreateInsertSql(record)

业务2.针对导入excel
如法炮制 须要什么？须要列的下标 列内容非空验证 重复性验证 格式验证 长度验证

1.自定义特效
using System;

namespace PublicLibrary.attr

{

//导入的注解【特征值/注解】
[AttributeUsage(AttributeTargets.Field, AllowMultiple = true)]
public class ColumnInfoAttr:Attribute{
    //位置
    int index = -1;

    // 长度
    int length = 32;

    // 是否为空
    bool nullable = false;

    // 时间格式
    string dateFormat = "";

    //正则表单式 验证数据格式
    string pattern = "";

    public ColumnInfoAttr(int index, int length){
        this.index = index;
        this.length = length;
    }

    public ColumnInfoAttr(int index, int length, bool nullable)
    {
        this.index = index;
        this.length = length;
        this.nullable = nullable;
    }

    public ColumnInfoAttr(int index, int length, bool nullable,string dateFormat)
    {
        this.index = index;
        this.length = length;
        this.nullable = nullable;
        this.dateFormat = dateFormat;
    }

    public ColumnInfoAttr(int index, int length, bool nullable, string dateFormat, string pattern)
    {
        this.index = index;
        this.length = length;
        this.nullable = nullable;
        this.dateFormat = dateFormat;
        this.Pattern = pattern;
    }

    public int Index { get => index; set => index = value; }
    public int Length { get => length; set => length = value; }
    public bool Nullable { get => nullable; set => nullable = value; }
    public string DateFormat { get => dateFormat; set => dateFormat = value; }
    public string Pattern { get => pattern; set => pattern = value; }
}

}
2.公共方法【注此部分没有校验重复性】
using System;
using System.Collections.Generic;
using System.Data;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using System.Windows.Forms;
using ess_zbfz_main.dto;
using ExcelDataReader;
using PublicLibrary;
using PublicLibrary.attr;

namespace ess_zbfz_main.util
{

//导入工具类
public class ExcelUtil
{

    //, Dictionary<string, string> dbListDict, string[] keys
    public static MessageInfo<T> ReadExcel<T>(int firstIndex){
        MessageInfo<T> messageInfo = new MessageInfo<T>();
        FileStream fileStream =null;
        IExcelDataReader reader = null;
        DataSet result = null;
      
        try
        {
            //小于0 默认是第三行开始读取
            firstIndex = firstIndex < 0 ? 2 : firstIndex;

            OpenFileDialog fileImportDialog = new OpenFileDialog();
            fileImportDialog.Filter = "导入文件包(*.xlsx)|*.xlsx";//扩展名
            fileImportDialog.FileName = "";
            if (fileImportDialog.ShowDialog() == DialogResult.OK)
            {
                string saveTempPath = @System.AppDomain.CurrentDomain.BaseDirectory + "data\\receiveData\\";//临时存放的路径
                /* if (!File.Exists(saveTempPath))
                 {
                     File.Create(saveTempPath);
                 }*/
                string saveName = fileImportDialog.FileName.Substring(fileImportDialog.FileName.LastIndexOf("\\") + 1);
                string dataPath = saveTempPath + saveName;//文件地址
                File.Copy(fileImportDialog.FileNames[0], dataPath, true);

                //解析处理  start
                //stream = 
                fileStream = File.Open(fileImportDialog.FileName, FileMode.Open, FileAccess.Read);
                reader = ExcelReaderFactory.CreateReader(fileStream);

                object[] curObject = new object[10];

                result = reader.AsDataSet(new ExcelDataSetConfiguration()
                {
                    ConfigureDataTable = (_) => new ExcelDataTableConfiguration()
                    {
                        UseHeaderRow = true,
                        ReadHeaderRow = (rowReader) =>
                        {
                            // 从第几行以后开始读取
                            int index = firstIndex;
                            if (index != rowReader.Depth)
                            {
                                rowReader.Read();
                            }
                        }
                    }
                });
                DataTableCollection tableCollection = result.Tables;

                //初步处理的数据
                messageInfo = GetmessageInfo<T>(tableCollection[0], firstIndex);

                //reader.Close();
                return messageInfo;

            }
        }
        catch(Exception ex) {
            Console.WriteLine(ex.Message);
            MessageBox.Show("导入文件错误信息：" + ex.Message);
        }
        finally{
            //须要释放资源
            if (reader != null)
            {
                reader.Close();
            }   
            if (fileStream != null)
            {
                fileStream.Close();
            }
            if (result != null)
            {
                result.Clear();
            }
        }
        
        return messageInfo;
    }

    public static MessageInfo<T> GetmessageInfo<T>(DataTable dt, int firstIndex)
    {
        MessageInfo<T> messageInfo = new MessageInfo<T>();

        bool existError = false;

        int totalCount = dt.Rows.Count;

        int successCount = 0;

        //错误信息
        StringBuilder errorSb = new StringBuilder();

        BindingFlags bindingFlags = BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic;
        var list = new List<T>();
        Type type = typeof(T);

        ColumnInfoAttr columnInfoAttr = null;

        FieldInfo[] fieldInfos = type.GetFields(bindingFlags);

        Dictionary<int, PropertyInfo> dictionAry = new Dictionary<int, PropertyInfo>();

        Dictionary<int, ColumnInfoAttr> columnDic = new Dictionary<int, ColumnInfoAttr>();

        //行属性
        //PropertyInfo propertyInfo = type.GetProperty("CurExcelIndex");

        for (int p = 0; p < fieldInfos.Length; p++)
        {
            columnInfoAttr = fieldInfos[p].GetCustomAttribute<ColumnInfoAttr>();
            if (columnInfoAttr != null)
            {
                dictionAry.Add(columnInfoAttr.Index, type.GetProperty(SQLiteSqlUtils.UpperCaseFirst(fieldInfos[p].Name)));
                columnDic.Add(columnInfoAttr.Index, columnInfoAttr);
            }
        }

        PropertyInfo currentProp = null;

        //实体
        T s;
        bool flag = false;

        int currentRow = firstIndex;

        foreach (DataRow item in dt.Rows){
            currentRow++;

            s = Activator.CreateInstance<T>();

            for (int i = 0; i < dt.Columns.Count; i++)
            {

                if (dictionAry.ContainsKey(i)){
                    currentProp = dictionAry[i];
                    columnInfoAttr = columnDic[i];
                    object v = null;

                    if (currentProp.PropertyType.ToString().Contains("System.Nullable"))
                    {
                        v = Convert.ChangeType(item[i], Nullable.GetUnderlyingType(currentProp.PropertyType));
                    }
                    else{
                        v = Convert.ChangeType(item[i], currentProp.PropertyType);
                    }

                    //不能够为空==> 非空验证
                    if (!columnInfoAttr.Nullable && (v == null || v.ToString().Trim().Length<=0))
                    {
                        //successCount++;
                        existError = true;
                        errorSb.Append("第" + currentRow + "行，" + dt.Columns[i].ColumnName + " 数据不得为空\n");
                        flag = true;
                        //break;
                    }

                    //不为空 超过了最大长度==> 长度验证
                    if (v != null && columnInfoAttr.Length < v.ToString().Length)
                    {
                        //successCount++;
                        existError = true;
                        errorSb.Append("第" + currentRow + "行，" + dt.Columns[i].ColumnName + " 数据长度不得超过" + columnInfoAttr.Length + "个字符\n");
                        flag = true;
                        //break;
                    }

                    //正则验证部分==> 数据格式验证
                    if (v != null && columnInfoAttr.Pattern!=null && columnInfoAttr.Pattern != "" && v.ToString().Trim().Length > 0){
                        //不匹配正则
                        if(!Regex.IsMatch(v.ToString().Trim(), columnInfoAttr.Pattern))
                        {
                            existError = true;
                            errorSb.Append("第" + currentRow + "行，" + dt.Columns[i].ColumnName + " 数据格式不正确");
                            flag = true;
                        }
                    }

                    //是否校验不合格
                    if (flag) {
                        flag = false;
                        successCount++;
                        break;
                    }
                    currentProp.SetValue(s, v, null);

                }

            }

            currentProp = dictionAry[-10];
            currentProp.SetValue(s, currentRow, null);//设置excel的行列
            currentProp = null;

            list.Add(s);
        }
        //返回的信息
        messageInfo.Record = list;
        messageInfo.ErrorInfo = errorSb.ToString();
        messageInfo.TotalCount = totalCount;
        messageInfo.ErrorCount = totalCount - successCount;
        messageInfo.SuccessCount = successCount;
        messageInfo.ExistError = existError;

        return messageInfo;
    }

}

}
3.具体的使用

实体：

方法调用:

int firstIndex = 2;

MessageInfo<OsZbSupplierProductInfo> messageInfo = ExcelUtil.ReadExcel<OsZbSupplierProductInfo>(firstIndex);

本文来源于：宋文超super，专属平台有csdn、思否(SegmentFault)、 简书、 开源中国(oschina)，转载请注明出处。