C # simple generation and application DLL file (database connection)

1. First create a project class library in C # and add the files opertedatabase. CS and cache. CS.

The Code is as follows:

File opertedatabase. CS

Using system; <br/> using system. collections. generic; <br/> using system. text; <br/> using system. data; <br/> using system. data. SQL; <br/> using system. data. sqlclient; <br/> using system. configuration; <br/> using system. collections; <br/> using system. XML. LINQ; </P> <p> namespace databasebing <br/> {<br/> public class opertedatabase <br/>{< br/> Private Static string connectionstirngname; <br/> private stat IC sqlconnection conn; <br/> Private Static int count; <br/> Public static int count <br/> {<br/> Get <br/> {<br/> return count; <br/>}< br/> set <br/> {<br/> COUNT = value; <br/>}< br/> Public static string connstrname <br/>{< br/> Get <br/>{< br/> return connectionstirngname; <br/>}< br/> set <br/>{< br/> If (! String. isnullorempty (value) <br/>{< br/> connectionstirngname = value; <br/>}< br/> Private Static sqlconnection getsqlconnection () <br/>{< br/> string constr = (string) cache. getdata (connectionstirngname); <br/> If (string. isnullorempty (constr) <br/>{< br/> try <br/>{< br/> constr = convert. tostring (configurationmanager. connectionstrings [connectionstirngname]. connectionstring; <B R/>}< br/> catch (exception ex) <br/>{< br/> throw new exception (ex. message, ex); <br/>}< br/> cache. cachingdata (connectionstirngname, constr); <br/>}< br/> return New sqlconnection (constr); <br/>}< br/> Public static sqlcommand getsqlcommand (string strsql) <br/>{< br/> If (! String. isnullorempty (strsql) <br/>{< br/> conn = getsqlconnection (); <br/> If (Conn. state = connectionstate. closed) <br/> Conn. open (); <br/> sqlcommand cmd = new sqlcommand (strsql, Conn); <br/> return cmd; <br/>}< br/> else <br/> return NULL; <br/>}< br/> Public static sqlcommand getsqlcommand (string procname, Params sqlparameter [] PARAM) <br/>{< br/> conn = getsqlconnection (); <br/> If (Conn. s Tate = connectionstate. closed) <br/> Conn. open (); <br/> sqlcommand cmd = new sqlcommand (procname, Conn); <br/> cmd. commandtype = commandtype. storedprocedure; <br/> If (Param! = NULL) <br/>{< br/> foreach (sqlparameter paramerter In Param) <br/>{< br/> cmd. parameters. add (paramerter); <br/>}</P> <p >}< br/> return cmd; </P> <p >}< br/> Public static void executesqlcommand (string strsql) <br/>{< br/> If (! String. isnullorempty (strsql) <br/>{< br/> getsqlcommand (strsql ). executenonquery (); <br/> If (Conn. state = connectionstate. open) <br/> Conn. close (); <br/>}< br/> Public static void executesqlcommand (string procname, sqlparameter [] PARAM) <br/>{< br/> getsqlcommand (procname, Param ). executenonquery (); <br/> If (Conn. state = connectionstate. open) <br/> Conn. close (); </P> <p >}< br/> Public St Atic dataset getdataset (string strsql) <br/>{< br/> If (! String. isnullorempty (strsql) <br/>{< br/> sqlcommand cmd = getsqlcommand (strsql); <br/> COUNT = (INT) cmd. executescalar (); <br/> sqldataadapter SDA = new sqldataadapter (CMD); <br/> dataset DS = new dataset (); <br/> SDA. fill (DS); <br/> If (Conn. state = connectionstate. open) <br/> Conn. close (); <br/> return Ds; <br/>}< br/> else <br/> return NULL; <br/>}< br/> Public static dataset getdataset (Str Ing procname, sqlparameter [] PARAM) <br/>{< br/> sqlcommand cmd = getsqlcommand (procname, Param); <br/> COUNT = (INT) cmd. executescalar (); <br/> sqldataadapter SDA = new sqldataadapter (getsqlcommand (procname, Param); <br/> dataset DS = new dataset (); <br/> SDA. fill (DS); <br/> If (Conn. state = connectionstate. open) <br/> Conn. close (); <br/> return Ds; <br/>}< br/> Private Static sqlparameter creat Eparam (string paramename, sqldbtype dbtype, int32 size, parameterdirection direction, object Value) <br/>{< br/> sqlparameter Param; <br/> If (size> 0) <br/>{< br/> param = new sqlparameter (paramename, dbtype, size ); <br/>}< br/> else <br/> param = new sqlparameter (paramename, dbtype); <br/> param. direction = direction; <br/> If (! (Direction = parameterdirection. output & value = NULL) <br/>{< br/> param. value = value; <br/>}< br/> return Param; <br/>}< br/> Public static sqlparameter createinputparam (string paramename, sqldbtype dbtype, int32 size, object value) <br/>{< br/> return createparam (paramename, dbtype, size, parameterdirection. input, value); <br/>}< br/> Public static sqlparameter createoutputparam (string paramename, sqldbtype dbtype, int32 size) <br/>{< br/> return createparam (paramename, dbtype, size, parameterdirection. output, null); <br/>}< br/> Public static sqlparameter createreturnvalueparam (string paramename, sqldbtype dbtype, int32 size) <br/>{< br/> return createparam (paramename, dbtype, size, parameterdirection. returnvalue, null); <br/>}</P> <p >}< br/>}</P> <p>

File Cache. CS

Using system; <br/> using system. collections. generic; <br/> using system. text; <br/> using system. collections; </P> <p> namespace databasebing <br/> {<br/> class cache <br/>{< br/> Private Static hashtable cache = hashtable. synchronized (New hashtable (); <br/> Public static void cachingdata (string key, object Value) <br/>{< br/> cache [Key] = value; <br/>}< br/> Public static object getdata (string key) <br/>{< br/> return (object) cache [Key]; <br/>}</P> <p>

2. Test the preceding two files to the C:/Windows/Microsoft. NET/framework/v2.0.50727 directory. The C # compiler, CSC. EXE, is provided under this directory.

3. Open the command window-> Enter cmd to the console-> Cd C:/Windows/Microsoft. NET/framework/v2.0.50727

4. Run the CSC command CSC/Target: Library/out: databasebingdll. dll opertedatabase. CS cache. CS.

5. After completing the preceding steps, you can find the DLL file databasebingdll. dll in this directory.

Note:

/Target: the Library compiler option notifies the compiler to output the DLL file instead of the EXE file. The/out compiler option followed by the file name is used to specify the DLL file name.

6. Create a new website. In Solution Explorer, right-click the project name and choose "add reference"> "add reference" to view databasebingdll. dll. Click "add.

7. Drag a gridview control on the default page of the project and run the following code in default. CS:Using system; <br/> using system. collections; <br/> using system. configuration; <br/> using system. data; <br/> using system. LINQ; <br/> using system. web; <br/> using system. web. security; <br/> using system. web. ui; <br/> using system. web. UI. htmlcontrols; <br/> using system. web. UI. webcontrols; <br/> using system. web. UI. webcontrols. webparts; <br/> using system. XML. LINQ; </P> <p> Public partial class _ default: system. web. UI. page <br/>{< br/> protected void page_load (Object sender, eventargs e) <br/>{</P> <p> opertedatabase. connstrname = "onlineresconnectionstring"; <br/> opertedatabase. getdataset ("select * from customer"); <br/> gridview1.datasource = opertedatabase. getdataset ("select * from customer "). tables [0]; <br/> gridview1.databind (); </P> <p >}< br/>