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C#提高xml读写速度方法
时间:2022-06-25 06:36:40 编辑:袖梨 来源:一聚教程网
dim domxmldocument as system.xml.xmldocument
dim tmppath as string = apptempfilepath
dim xmlfile 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) handles mybase.load
’读xml过程测试通过
dim domxmldocument as system.xml.xmldocument
dim tmppath as string = apptempfilepath
dim xmlfile as string = tmppath + "\testxml.xml"
dim reader as system.xml.xmlreader = nothing
try
reader = new xml.xmltextreader(xmlfile)
’reader.
while reader.read
me.lboxxml.items.add(reader.name + reader.value)
end while
catch ex as exception
msgbox(ex.message)
finally
if not (reader is nothing) then
reader.close()
end if
end try
end sub
’载入xml事件
private sub btnxmlload_click(byval sender as system.object, byval e as system.eventargs) handles btnxmlload.click
’me.lboxxml.items.clear()
’’读xml过程测试通过
’dim reader as system.xml.xmlreader = nothing
’try
’ reader = new xml.xmltextreader(xmlfile)
’ while reader.read
’ me.lboxxml.items.add(reader.name + ":" + reader.value)
’ end while
’catch ex as exception
’ msgbox(ex.message)
’finally
’ if not (reader is nothing) then
’ reader.close()
’ end if
’end try
dim ds as new dataset
try
’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(xmlfile)
dim tb as datatable
dim dv as dataview
tb = ds.tables(0)
dv = new dataview(tb)
datagrid1.datasource = dv
’datagrid1.datamember = "testxmlmember"
’datagrid1.datamember = "employeefname"
’dim dxd as new xmldatadocument
catch ex as exception
msgbox(ex.message.tostring)
end try
end sub
’保存新建xml内容事件
private sub btnsavenew_click(byval sender as system.object, byval e as system.eventargs) handles btnsavenew.click
dim mytw as new xmltextwriter(tmppath + "\testxmlwrite.xml", nothing)
mytw.writestartdocument()
mytw.formatting = formatting.indented
mytw.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linq 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。