Research on bindingmanagerbase

Source code: http://download.csdn.net/source/1048586

App. config<? XML version = "1.0" encoding = "UTF-8"?> <Br/> <configuration> <br/> <connectionstrings> <br/> <Add name = "connectionstring" <br/> connectionstring = "provider = Microsoft. jet. oledb.4.0; Data Source = | datadirectory |/appdata/DB. MDB; persist Security info = true "<br/> providername =" system. data. oledb "/> <br/> </connectionstrings> <br/> </configuration>Dataaccess. CSUsing system; <br/> using system. collections. generic; <br/> using system. LINQ; <br/> using system. text; </P> <p> using system. data; <br/> using system. data. oledb; </P> <p> namespace hellovs2008.appcode <br/> {<br/> public class dataaccess <br/>{< br/> // Add reference system here. configuration, not just using. <br/> static string strcon = system. configuration. configurationmanager. connectionstrings ["connectionstring"]. tostring (); </P> <p> // <summary> <br/> // execute the query, return dataset <br/> /// </Summary> <br/> // <Param name = "sqlstr"> SQL statement </param> <br/> // /<Param name = "tablename"> table name </param> <br/> // <returns> </returns> <br/> Public static dataset getdataset (string sqlstr, string tablename) <br/>{< br/> oledbconnection conn = new oledbconnection (strcon); <br/> dataset DS = new dataset (); <br/> Conn. open (); <br/> oledbdataadapter da = new oledbdataadapter (sqlstr, Conn); <br/> da. fill (DS, tablename); <br/> Conn. close (); <br/> return Ds; <br/>}</P> <p> // <summary> <br/> // execute a non-query SQL statement <br/> /// </ summary> <br/> /// <Param name = "sqlstr"> </param> <br/> /// <returns> </returns> <br/> Public static int executesql (string sqlstr) <br/>{< br/> using (oledbconnection conn = new oledbconnection (strcon) <br/>{< br/> oledbcommand cmd = new oledbcommand (); <br/> cmd. connection = conn; <br/> cmd. commandtext = sqlstr; <br/> Conn. open (); <br/> cmd. executenonquery (); <br/> Conn. close (); <br/> return 1; <br/>}< br/>Dataform. CSUsing system; <br/> using system. collections. generic; <br/> using system. componentmodel; <br/> using system. data; <br/> using system. drawing; <br/> using system. LINQ; <br/> using system. text; <br/> using system. windows. forms; </P> <p> using system. data. oledb; </P> <p> namespace hellovs2008 <br/> {<br/> Public partial class dataform: Form <br/>{< br/> private dataset Ds; <br/> private bindingmanagerbase mybind; <Br/> Public dataform () <br/>{< br/> initializecomponent (); <br/>}</P> <p> private void dataform_load (Object sender, eventargs e) <br/>{< br/> DS = appcode. dataaccess. getdataset ("select * From workerinf", "workerinf"); <br/> // Add ("attributes to be bound ", "Control bound to the source", "attributes bound to the source"); <br/> this.txt bind. databindings. add ("text", DS, "workerinf. name "); <br/> // bind the title to the content in a textbox and synchronize it. <Br/> This. databindings. add ("text", txttext, "text"); <br/> // use form's bindingcontext to obtain bindingmanagerbase <br/> mybind = This. bindingcontext [ds, "workerinf"]; <br/>}</P> <p> private void btnnext_click (Object sender, eventargs E) <br/>{< br/> If (mybind. position = mybind. count-1) <br/> MessageBox. show ("the last record has been reached! "," Message prompt! ", Messageboxbuttons. OK, messageboxicon. information); <br/> else <br/> mybind. position + = 1; <br/>}</P> <p> private void btnprep_click (Object sender, eventargs e) <br/>{< br/> If (mybind. position = 0) <br/> MessageBox. show ("the first record has been reached! "," Message prompt! ", Messageboxbuttons. OK, messageboxicon. information); <br/> else <br/> mybind. position-= 1; <br/>}</P> <p> private void btnfirst_click (Object sender, eventargs e) <br/>{< br/> mybind. position = 0; <br/>}</P> <p> private void btnlast_click (Object sender, eventargs e) <br/>{< br/> mybind. position = mybind. count-1; <br/>}</P> <p> private void btnexecutesql_click (Object sender, eventargs e) <br/> {<Br/> // the key point is to execute database updates and update the data in the memory. Datarow <br/> // insertrecord (); <br/> // deleterecord (); <br/> UpdateRecord (); <br/>}</P> <p> protected void insertrecord () <br/>{< br/> try <br/>{< br/> // construct an SQL statement based on the input control value <br/> string strinsert = "insert into workerinf (name, sex) values ('gv ', 'male') "; <br/> // perform database operations <br/> appcode. dataaccess. executesql (strinsert); <br/> // updates memory data <br/> DS. tables ["workerinf"]. rows [mybind. position]. beginedit (); <Br/> // construct datarow <br/> datarow DR = Ds. tables ["workerinf"]. newrow (); <br/> Dr ["name"] = "hello"; <br/> Dr ["sex"] = "male"; <br/> DS. tables ["workerinf"]. rows. add (DR); <br/> DS. tables ["workerinf"]. rows [mybind. position]. endedit (); <br/> DS. tables ["workerinf"]. acceptchanges (); <br/>}< br/> catch (exception ed) <br/>{< br/> MessageBox. show ("adding data records" + ed. tostring (), "error! "); <Br/>}< br/> protected void deleterecord () <br/> {<br/> try <br/> {<br/> // delete a condition and obtain it from bindingmanagerbase <br/> // MessageBox. show (Ds. tables ["workerinf"]. rows [mybind. position] ["name"]. tostring (); </P> <p> // perform database operations <br/> string strinsert = "delete from workerinf where name = 'gv '"; <br/> appcode. dataaccess. executesql (strinsert); <br/> // update internal data <br/> DS. tables ["workerinf"]. rows [mybind. positi On]. beginedit (); <br/> DS. tables ["workerinf"]. rows [mybind. position]. delete (); <br/> DS. tables ["workerinf"]. rows [mybind. position]. endedit (); <br/> DS. tables ["workerinf"]. acceptchanges (); <br/>}< br/> catch (exception ed) <br/>{< br/> MessageBox. show ("deleting data records occurred" + ed. tostring (), "error! "); <Br/>}< br/> protected void UpdateRecord () <br/> {<br/> try <br/> {<br/> // perform database operations <br/> // string strinsert = "Update workerinf set name =' gv1 ', sex = 'female 'Where name = 'tree' "; <br/> // appcode. dataaccess. executesql (strinsert); <br/> // update internal data <br/> DS. tables ["workerinf"]. rows [mybind. position]. beginedit (); <br/> datarow DR = Ds. tables ["workerinf"]. rows [mybind. position]; <br/> Dr ["name"] =" Gv1 "; <br/> Dr [" sex "] =" female "; <br/> DS. tables ["workerinf"]. rows [mybind. position]. endedit (); <br/> DS. tables ["workerinf"]. acceptchanges (); <br/>}< br/> catch (exception ed) <br/>{< br/> MessageBox. show ("updating data records occurred" + ed. tostring (), "error! "); <Br/>}< br/>