事件C 提高xml读写速方法

dim domxmldocument as system.xml .xmldocumentdim tmppath as string=apptempfi lepathdim xmlfi le as string=tmppath+" \testxml .xml"

'窗体加载事件private sub testxml_load(byval sender as system.object, byval e as system.eventargs)handlesmybase. load

'读xm l过程测试通过dim domxmldocument as system.xml .xmldocumentdim tmppath as string=apptempfi lepathdim xmlfi le as string=tmppath+" \testxml .xml"dim reader as system.xml .xmlreader=nothingt ryreader=new xml .xmltextreader(xmlfi le)

'reader.whi le reader.readme. lboxxml . items.add(reader.name+reader.value)end whi lecatch ex as exceptionmsgbox(ex.message)final lyif not (reader is nothing) thenreader.close()end ifend tryend sub

'载入xm l事件private sub btnxml load_cl ick(byval sender as system.object, byval e as system.eventargs)handles btnxml load.cl ick

'me. lboxxml . items.clear()

' '读xm l过程测试通过

'dim reader as system.xml .xmlreader=nothing

't ry

' reader=new xml .xmltextreader(xmlfi le)

'whi le reader.read

'me. lboxxml . items.add(reader.name+":"+reader.value)

'end whi le

'catch ex as exception

'msgbox(ex.message)

'final ly

' if not (reader is nothing) then

'reader.close()

'end ifend trydim ds as new dataset

t ry

'如果直接使用ds做datasource则不会展开datagrid用dv则能直接显示正确。ds.readxml(xmlfi le)dim tb as datatabledim dv as dataviewtb=ds.tables(0)dv=new dataview(tb)datagrid1 .datasource=dv

'datagrid1 .datamember="testxmlmember"

'datagrid1 .datamember="employeefname"

'dim dxd as new xmldatadocumentcatch ex as exceptionmsgbox(ex.message.tostring)end tryend sub

'保存新建xm l内容事件private sub btnsavenew_cl ick(byval sender as system.object, byval e as system.eventargs)handles btnsavenew.cl ickdim mytw as new xmltextwriter(tmppath+" \ testxmlwrite.xml", nothing)mytw.writestartdocument()mytw.formatting=formatting. i ndentedmytw.writestartelement("team")mytw.writestartelement("player")mytw.writeattributestring("name", "george zip")mytw.writeattributestring("position”, "qb")mytw.writeelementstring("nickname", "zippy")mytw.writeelementstring("jerseynumber",xmlconvert.tostring(7))mytw.writeendelement()mytw.writeendelement()mytw.writeenddocument()mytw.close()end sub

文件很大的情况下可以考虑手动实现数据更新适配器 比如手动实现一个 xml节点搜索/更新这样就不用重写整个 xml。

如果程序的i/o不是主要问题还是用实体类整个的写入更新吧毕竟数据的完整性是第一位的。

如是文章类的对该目录建一个 xml索引文件来存放文章的编号 url等用xml的attribute作为标记不同字段 内容页面可以用另外的 html或xml页面存放用l inq to xml操作数据效率不是很差个人观点。当搜索时候只要查询指定文件名 xml或文件类型就可以了。

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