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C#读取数据库返回泛型集合详解(DataSetToList)

程序员文章站 2024-02-13 21:12:22
复制代码 代码如下:protected void page_load(object sender, eventargs e)    ...

复制代码 代码如下:

protected void page_load(object sender, eventargs e)
        {
            if (!ispostback)
            {
                ilist<lyzx.model.lyzx_newstypemodel> list = getlist<lyzx.model.lyzx_newstypemodel>(system.configuration.configurationmanager.connectionstrings["connstr"].connectionstring,
               "select * from lyzx_newstype");

                gridview1.datasource = list;
                gridview1.databind();
            }
        }

        public string getnewstypelink(ref string baseurl,guid newstype)
        {
            return "";
        }

        /// <summary>        
        /// 获取泛型集合        
        /// /// </summary>        
        /// /// <typeparam name="t">类型</typeparam>        
        /// /// <param name="connstr">数据库连接字符串</param>        
        /// <param name="sqlstr">要查询的t-sql</param>        
        /// <returns></returns>        
        public ilist<t> getlist<t>(string connstr, string sqlstr)       
        {            
            using (sqlconnection conn = new sqlconnection(connstr))           
            {               
                using (sqldataadapter sda = new sqldataadapter(sqlstr, conn))               
                {                 
                    dataset ds = new dataset();                    
                    sda.fill(ds);                   
                    return datasettolist<t>(ds, 0);               
                }           
            }      
        }


        /// <summary>        
        /// datasettolist        
        /// </summary>         
        /// <typeparam name="t">转换类型</typeparam>        
        /// <param name="dataset">数据源</param>        
        /// <param name="tableindex">需要转换表的索引</param>       
        /// /// <returns>泛型集合</returns>
        public ilist<t> datasettolist<t>(dataset dataset,int tableindex)
        {
            //确认参数有效
            if (dataset==null || dataset.tables.count<=0|| tableindex<0)
            {
                return null;
            }

            datatable dt = dataset.tables[tableindex];

            ilist<t> list = new list<t>();


            for (int i = 0; i < dt.rows.count; i++)
            {
                //创建泛型对象
                t _t=activator.createinstance<t>();

                //获取对象所有属性
                propertyinfo [] propertyinfo=_t.gettype().getproperties();

                //属性和名称相同时则赋值
                for (int j = 0; j < dt.columns.count; j++)
                {
                    foreach (propertyinfo info in propertyinfo)
                    {
                        if (dt.columns[j].columnname.toupper().equals(info.name.toupper()))
                        {
                            if (dt.rows[i][j]!=dbnull.value)
                            {
                                info.setvalue(_t, dt.rows[i][j], null);
                            }
                            else
                            {
                                info.setvalue(_t, null, null);
                            }

                            break;
                        }
                    }
                }

                list.add(_t);
            }

            return list;
        }