C#winfrom database additions and deletions to verify the case--dataadapter version

Using system;using system.collections.generic;using system.componentmodel;using system.data;using System.Drawing; Using system.linq;using system.text;using system.windows.forms;using system.data.oledb;using System.Configuration; namespace testdboper2{public partial class Form1:form {static string m_connstr = Configurationmanager.con nectionstrings["ConnStr"].                ConnectionString;        OleDbConnection M_conn;        OleDbCommand M_cmd;        OleDbDataAdapter M_da;        DataTable M_dt;          Enum Dbstate {dsadd,//Add state dsmod,//Modify State dsdel,//Delete State Dsbro//Browse State               } dbstate m_dbstate;            Public Form1 () {InitializeComponent ();            M_conn = new OleDbConnection (M_CONNSTR);            M_cmd = new OleDbCommand ("SELECT * from Users", m_conn);            M_da = new OleDbDataAdapter (m_cmd);            OleDbCommandBuilder cb = new OleDbCommandBuilder (M_DA); M_DT = nEW DataTable ();        Datagridview1.datasource = M_dt; private void Form1_Load (object sender, EventArgs e) {datagridview1.autogeneratecolumns = False            ;        Btnquery_click (sender, E); }//query private void Btnquery_click (object sender, EventArgs e) {m_dbstate = Dbstate.dsbro            ;            Setbtnstate ();            M_cmd.commandtext = "SELECT * from the users where username like '%" +textbox2.text+ "% '"; M_dt.            Clear (); M_da.            Fill (M_DT); M_conn.          Close ();            }//Added private void btnAdd_Click (object sender, EventArgs e) {m_dbstate = Dbstate.dsadd;            Setbtnstate ();            txtUsername.Text = "";            Txtuserage.text = "";        Txtusersex.text = ""; }//Modify private void Btnmod_click (object sender, EventArgs e) {if (datagridview1.currentce ll. RowIndex >= M_dt.      Rows.Count) {return;}      M_dbstate = Dbstate.dsmod;            Setbtnstate (); txtUsername.Text = M_dt. rows[datagridview1.currentcell.rowindex]["username"].            ToString (); Txtuserage.text = M_dt. rows[datagridview1.currentcell.rowindex]["Userage"].            ToString (); Txtusersex.text = M_dt. rows[datagridview1.currentcell.rowindex]["Usersex"].        ToString (); }//delete private void Btndel_click (object sender, EventArgs e) {if (MessageBox.Show ("OK" to delete?            "," hint ", messageboxbuttons.yesno) = = dialogresult.no) {return;} try {M_dt. Rows[datagridview1.currentcell.rowindex].                Delete (); M_da. Update (M_dt.                GetChanges ()); M_dt.                AcceptChanges ();            MessageBox.Show ("delete succeeded"); } catch (Exception ex) {MessageBox.Show ("Delete failed" +ex.            Message); }}//double-click private void Datagridview1_celldoubleclick (object sender, DatagridviewcelleveNtargs e) {Btnmod_click (sender, E); }//Save private void Btnsave_click (object sender, EventArgs e) {if (m_dbstate = = DBSTATE.D Smod) {try {DataRow dr= m_dt.                    Rows[datagridview1.currentcell.rowindex]; Dr.                    BeginEdit ();                    dr["username"] = txtUsername.Text;                    dr["userage"] = Txtuserage.text;                    dr["usersex"] = Txtusersex.text; Dr.                    EndEdit (); M_da. Update (M_dt.                    GetChanges ()); M_dt.                    AcceptChanges ();                MessageBox.Show ("saved successfully"); } catch (Exception ex) {MessageBox.Show ("Save failed" + ex.)                Message); }} else {try {DataRow Dr = M_dt.                    NewRow (); dr["username"] = Txtusername.texT                    dr["userage"] = Txtuserage.text;                    dr["usersex"] = Txtusersex.text; M_dt.                    Rows.Add (DR); M_da. Update (M_dt.                    GetChanges ()); M_dt.                    AcceptChanges ();                MessageBox.Show ("increased success"); } catch (Exception ex) {MessageBox.Show ("Increase failed" +ex.                Message);            }} m_dbstate = Dbstate.dsbro;        Setbtnstate ();            } private void Btncancel_click (object sender, EventArgs e) {m_dbstate = Dbstate.dsbro;        Setbtnstate ();            } private void Setbtnstate () {btnquery.enabled = M_dbstate = = Dbstate.dsbro;            btnadd.enabled = M_dbstate = = Dbstate.dsbro;            btnmod.enabled = M_dbstate = = Dbstate.dsbro;            btndel.enabled = M_dbstate = = Dbstate.dsbro;            btnsave.enabled = m_dbstate! = Dbstate.dsbro; Btncancel.enabled = m_dbstate! = Dbstate.dsbro; }    }}

C#winfrom database additions and deletions to verify the case--dataadapter version