反射问题

Question

   public IList<object> xx(DataTable myDt, object targetObj)
    {        System.Reflection.PropertyInfo[] ps = targetObj.GetType().GetProperties();
        IList<object> list = new List<object>();
        foreach (DataRow row in myDt.Rows)
        {
            foreach (System.Reflection.PropertyInfo p in ps)
            {
                if (row[p.Name] != null)
                {
                    p.SetValue(targetObj, row[p.Name], null);
                }
            }
            list.Add(ps);
            
        }        return list;
    }  我想写个通用的反射 ` `但学的年代太久了  各位帮忙完善下 谢谢` 

Answer 1

        public bool InsertEntity(IEntity entity)
        {
            SqlConnection conn = null;
            try
            {
                Type type = entity.GetType();
                PropertyInfo[] list = type.GetProperties();
                conn = GetSqlConnection();
                conn.Open();
                SqlCommand cmd = new SqlCommand();
                cmd.Connection = conn;                //生成sql语句
                StringBuilder sql = new StringBuilder();
                StringBuilder sqlValue = new StringBuilder();
                sql.Append("insert into " + type.Name + "(");
                sqlValue.Append(" values(");
                string keyName = this.GetKeyName(type.Name);
                foreach (PropertyInfo info in list)
                {
                    if (info.Name == keyName ||
                        info.GetValue(entity, null) == null)
                    {
                        continue;
                    }
                    sql.Append("[" + info.Name + "],");
                    sqlValue.Append("@" + info.Name + ",");
                    SqlParameter p = new SqlParameter();
                    p.ParameterName = "@" + info.Name;
                    p.Value = info.GetValue(entity, null);
                    cmd.Parameters.Add(p);
                }
                string sqlGetId = "select max(" + keyName + ") from " + type.Name;
                string cmdText = sql.ToString().TrimEnd(new char[] { ',' }) + ")" +
                    sqlValue.ToString().TrimEnd(new char[] { ',' }) + ");" + sqlGetId;
                cmd.CommandText = cmdText;                //找主键
                PropertyInfo pi = null;
                foreach (PropertyInfo info in list)
                {
                    if (info.Name == keyName)
                    {
                        pi = info;
                        break;
                    }
                }                //执行并给ID赋值
                lock (_lock)
                {
                    object id = cmd.ExecuteScalar();
                    pi.SetValue(entity, id, null);
                }
                return true;
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
            finally
            {
                if (conn != null)
                {
                    conn.Close();
                }
            }
        }

Answer 2

IList<object>？把你的object删掉！

Answer 3

public object xx(DataTable myDt,Type t)
{    System.Reflection.PropertyInfo[] ps = t.GetProperties();
    object obj = t.Assembly.CreateInstance(t.FullName);
    foreach (DataRow row in myDt.Rows)
    {
        foreach (System.Reflection.PropertyInfo p in ps)
        {
            if (row[p.Name] != null)
            {
                p.SetValue(obj, row[p.Name], null);
            }
        }
    }
    return obj;
}

Answer 4

 public object GetEntity(DataRow row, object targetObj)
    {
        System.Reflection.PropertyInfo[] ps = targetObj.GetType().GetProperties();
        foreach (System.Reflection.PropertyInfo p in ps)
        {
            if (row[p.Name] is DBNull)
            {
               
            }
            else
            {
                p.SetValue(targetObj, row[p.Name], null);
            }        }        return targetObj;
    }

Answer 5

if (row[p.Name] != null)
 
   这样判断 如果INT32类型的变量数据库的值为NULL 会出错` 

Answer 6

至于如何判断那是你的事了，如果是null你可以多加判断