如何更新组合框，以便在将其添加到数据库后立即显示该记录？

本文介绍了如何更新组合框，以便在将其添加到数据库后立即显示该记录？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 嗨！ 这是我的代码，用于汇总数据库中的数据库。 Main_Load（ object sender，EventArgs e） { bindComboBox（）; } public void bindComboBox（） { DataTable table = new DataTable（）; conn.ConnectionString = connString; conn.Open（）; SqlDataAdapter da = new SqlDataAdapter（ SELECT * FROM KombiStateTbl，conn）; da.Fill（table）; kombiComboBox.DataSource = new BindingSource（table， null ）; kombiComboBox.DisplayMember = NumberPlate; kombiComboBox.ValueMember = NumberPlate; conn.Close（）; } 来自另一种表格的我可以将另一条记录添加到数据库中。我的问题是：如何更新组合框，以便在将其添加到数据库后立即显示该记录？ 这是添加记录的代码： private void okButton_Click（ object sender，EventArgs e） { int intInsert = 0 ; 字符串 connString =（ @ 数据源= .\SQLEXPRESS; AttachDbFilename = D：\Projects\RentalPlus\RentalPlus\KombiDB.mdf; Integrated Security = True; User Instance = True）; SqlConnection conn = new SqlConnection（connString）; SqlCommand cmd = new SqlCommand（）; cmd.CommandType = CommandType.Text; cmd.CommandText = INSERT INTO KombiStateTbl（NumberPlate，LicenseExpiryDate，ControlDate， + Documentos，FaróisLanternas，EstepeMacacoChaveDeRoda，Triângulo，Extintor，Acendedor， + RodasCalota，Retrovisores，Párabrisa，BancosTapetes，Pneus，ParachoqueDianteiro， + ParachoqueTraseiro，PortaDianteiraDireitaM，PortaDianteiraEsquerdaP，PortaLateral， + LateralEsquerda，LateralEsquerdaTraseira，LateralDireitaTraseira，ParalamaTraseiroDireito， + ParalamaTraseiroEsquerdo，Teto，PortaDoPortaMalas ，PortaTraseiraDoMotor，Traseira， + Dianteira，FaróisDianteiros，FaroisTraseiros，CurrentPic，CurrentPicPath） VALUES + （@ Param1，@ Param2，@ Param3，'OK'， 'OK'，'OK'，'OK'，'OK'，'OK'，'OK'，'OK'，'OK'，'OK'， + 确定，确定，确定，确定，确定，确定，确定， OK'，'OK'，'OK'，'OK'，'OK'，'OK'，'OK'， + 'OK'，'OK'，'OK'，'OK'，NULL，NULL）; cmd.Parameters.Add（ @ Param1，SqlDbType.Char ）.Value = noPlateTextBox.Text; cmd.Parameters.Add（ @ Param2，SqlDbType.Char）.Value = licenseDateTimePicker.Text; cmd.Parameters.Add（ @ Param3，SqlDbType.Char）.Value = controlDateTimePicker.Text; cmd.Connection = conn; conn.Open（）; intInsert = cmd.ExecuteNonQuery（）; conn.Close（）; if （intInsert！= 0 ） { MessageBox.Show（ 数据插入成功， 成功，MessageBoxButtons.OK， MessageBoxIcon.Information）; noPlateTextBox.Text = ; okButton.Enabled = false ; } else { MessageBox.Show（ 数据插入失败， 错误，MessageBoxButtons.RetryCancel， MessageBoxIcon.Error）; } } 请帮忙。解决方案 你需要做一个重新加载以重新收集更新的内容，然后在添加该内容后更新组合框的数据源。 这在if语句中应修复： if （intInsert！= 0 ） { MessageBox.Show（ 数据插入成功， 成功，MessageBoxButtons.OK， MessageBoxIcon.Information）; noPlateTextBox.Text = ; okButton.Enabled = false ; bindComboBox（）; // << - 更新后重新收集组合框的内容。 } 对不起，我唯一一个调用上面绑定行的错误。 只需添加在ok_Button.Enabled = false之后，在ok按钮内调用if条件; 所以你的okButton_Click看起来像这样： private void okButton_Click（object sender，EventArgs e） { int intInsert = 0; String connString =（@Data Source = .\SQLEXPRESS; AttachDbFilename = D：\Projects\RentalPlus\RentalPlus\KombiDB.mdf; Integrated Security = True; User Instance = True）; SqlConnection conn = new SqlConnection（connString）; SqlCommand cmd = new SqlCommand（）; cmd.CommandType = CommandType.Text; cmd.CommandText =INSERT INTO KombiStateTbl（NumberPlate，LicenseExpiryDate，ControlDate， +Documentos，FaróisLanternas，EstepeMacacoChaveDeRoda，Triângulo，Extintor，Acendedor， +RodasCalota，Retrovisores，Párabrisa ，BancosTapetes，Pneus，ParachoqueDianteiro， +ParachoqueTraseiro，PortaDianteiraDireitaM，PortaDianteiraEsquerdaP，PortaLateral， +LateralEsquerda，LateralEsquerdaTraseira，LateralDireitaTraseira，ParalamaTraseiroDireito， +ParalamaTraseiroEsquerdo，Teto，PortaDoPortaMalas， PortaTraseiraDoMotor，Traseira， +Dianteira，FaróisDianteiros，FaroisTraseiros，CurrentPic，CurrentPicPath）价值 +（@ Param1，@ Param2，@ Param3，''OK''，''OK'' ，''确定'，''确定''，''确定''，''确定''，''确定''，''确定''，''确定''，''确定''， +''确定''，' OK''，''OK''，''OK''，''OK''，''OK''，''OK''，''OK''，''OK''，''OK' '，''确定''，''确定''，''确定''，''确定''， +''确定''，''确定''，''确定''' ，''确定''，NULL，NULL）; cmd.Parameters.Add（@ Param1，SqlDbType.Char）.Value = noPlateTextBox.Text; cmd.Parameters.Add（@ Param2，SqlDbType.Char）.Value = licenseDateTimePicker.Text; cmd.Parameters.Add（@ Param3，SqlDbType.Char）.Value = controlDateTimePicker.Text; cmd.Connection = conn; conn.Open（）; intInsert = cmd.ExecuteNonQuery（）; conn.Close（）; if（intInsert！= 0） { MessageBox.Show（数据插入成功，成功，MessageBoxButtons.OK， MessageBoxIcon。信息）; noPlateTextBox.Text =; okButton.Enabled = false; Main_Load.bindComboBox（）; //这里是需要的电话<<<<< br mode =hold/> } else { MessageBox.Show（数据插入失败，错误，MessageBoxButtons.RetryCancel， MessageBoxIcon.Error）; } } 好的，我明白了。我发现它在互联网上的某个地方。它完成了这项工作！ 主要m =（主要）Application.OpenForms [ Main]; m.bindComboBox（）; wolfcoder75，谢谢你的输入。 Hi!this is my code to polulate a combobox with data from the database.Main_Load(object sender, EventArgs e) { bindComboBox(); } public void bindComboBox() { DataTable table = new DataTable(); conn.ConnectionString = connString; conn.Open(); SqlDataAdapter da = new SqlDataAdapter("SELECT * FROM KombiStateTbl", conn); da.Fill(table); kombiComboBox.DataSource = new BindingSource(table, null); kombiComboBox.DisplayMember = "NumberPlate"; kombiComboBox.ValueMember = "NumberPlate"; conn.Close(); }from another form I can add another record to the database. my question is: how to update the combobox so it shows that record right after it''s added to the db? this is the code to add a record:private void okButton_Click(object sender, EventArgs e) { int intInsert = 0; String connString = (@"Data Source=.\SQLEXPRESS;AttachDbFilename=D:\Projects\RentalPlus\RentalPlus\KombiDB.mdf;Integrated Security=True;User Instance=True"); SqlConnection conn = new SqlConnection(connString); SqlCommand cmd = new SqlCommand(); cmd.CommandType = CommandType.Text; cmd.CommandText = "INSERT INTO KombiStateTbl (NumberPlate, LicenseExpiryDate, ControlDate, " + "Documentos, FaróisLanternas, EstepeMacacoChaveDeRoda, Triângulo, Extintor, Acendedor, " + "RodasCalota, Retrovisores, Párabrisa, BancosTapetes, Pneus, ParachoqueDianteiro, " + "ParachoqueTraseiro, PortaDianteiraDireitaM, PortaDianteiraEsquerdaP, PortaLateral, " + "LateralEsquerda, LateralEsquerdaTraseira, LateralDireitaTraseira, ParalamaTraseiroDireito, " + "ParalamaTraseiroEsquerdo, Teto, PortaDoPortaMalas, PortaTraseiraDoMotor, Traseira, " + "Dianteira, FaróisDianteiros, FaroisTraseiros, CurrentPic, CurrentPicPath) VALUES " + "(@Param1,@Param2,@Param3, 'OK', 'OK', 'OK', 'OK', 'OK', 'OK', 'OK', 'OK', 'OK', 'OK', " + "'OK', 'OK', 'OK', 'OK', 'OK', 'OK', 'OK', 'OK', 'OK', 'OK', 'OK', 'OK', 'OK', 'OK', " + "'OK', 'OK', 'OK', 'OK', NULL, NULL)"; cmd.Parameters.Add("@Param1", SqlDbType.Char).Value = noPlateTextBox.Text; cmd.Parameters.Add("@Param2", SqlDbType.Char).Value = licenseDateTimePicker.Text; cmd.Parameters.Add("@Param3", SqlDbType.Char).Value = controlDateTimePicker.Text; cmd.Connection = conn; conn.Open(); intInsert = cmd.ExecuteNonQuery(); conn.Close(); if (intInsert != 0) { MessageBox.Show("The data insertion is successful", "Success", MessageBoxButtons.OK, MessageBoxIcon.Information); noPlateTextBox.Text = ""; okButton.Enabled = false; } else { MessageBox.Show("The data insertion is failed", "Error", MessageBoxButtons.RetryCancel, MessageBoxIcon.Error); } }Please help. 解决方案 You need to do a reload to recollect the updated content and then update the datasource of the combo box after you added that content.this in your if statement should fix that:if (intInsert != 0){ MessageBox.Show("The data insertion is successful", "Success", MessageBoxButtons.OK, MessageBoxIcon.Information); noPlateTextBox.Text = ""; okButton.Enabled = false; bindComboBox(); //<<- Recollect content for combobox after update.}sorry, my fault on the only calling the bind line above.Just add the call to your if condition inside your ok button click after ok_Button.Enabled = false;So your okButton_Click would look like this:private void okButton_Click(object sender, EventArgs e) { int intInsert = 0; String connString = (@"Data Source=.\SQLEXPRESS;AttachDbFilename=D:\Projects\RentalPlus\RentalPlus\KombiDB.mdf;Integrated Security=True;User Instance=True"); SqlConnection conn = new SqlConnection(connString); SqlCommand cmd = new SqlCommand(); cmd.CommandType = CommandType.Text; cmd.CommandText = "INSERT INTO KombiStateTbl (NumberPlate, LicenseExpiryDate, ControlDate, " + "Documentos, FaróisLanternas, EstepeMacacoChaveDeRoda, Triângulo, Extintor, Acendedor, " + "RodasCalota, Retrovisores, Párabrisa, BancosTapetes, Pneus, ParachoqueDianteiro, " + "ParachoqueTraseiro, PortaDianteiraDireitaM, PortaDianteiraEsquerdaP, PortaLateral, " + "LateralEsquerda, LateralEsquerdaTraseira, LateralDireitaTraseira, ParalamaTraseiroDireito, " + "ParalamaTraseiroEsquerdo, Teto, PortaDoPortaMalas, PortaTraseiraDoMotor, Traseira, " + "Dianteira, FaróisDianteiros, FaroisTraseiros, CurrentPic, CurrentPicPath) VALUES " + "(@Param1,@Param2,@Param3, ''OK'', ''OK'', ''OK'', ''OK'', ''OK'', ''OK'', ''OK'', ''OK'', ''OK'', ''OK'', " + "''OK'', ''OK'', ''OK'', ''OK'', ''OK'', ''OK'', ''OK'', ''OK'', ''OK'', ''OK'', ''OK'', ''OK'', ''OK'', ''OK'', " + "''OK'', ''OK'', ''OK'', ''OK'', NULL, NULL)"; cmd.Parameters.Add("@Param1", SqlDbType.Char).Value = noPlateTextBox.Text; cmd.Parameters.Add("@Param2", SqlDbType.Char).Value = licenseDateTimePicker.Text; cmd.Parameters.Add("@Param3", SqlDbType.Char).Value = controlDateTimePicker.Text; cmd.Connection = conn; conn.Open(); intInsert = cmd.ExecuteNonQuery(); conn.Close(); if (intInsert != 0) { MessageBox.Show("The data insertion is successful", "Success", MessageBoxButtons.OK, MessageBoxIcon.Information); noPlateTextBox.Text = ""; okButton.Enabled = false; Main_Load.bindComboBox(); //here is the call needed <<<<br mode="hold" /> } else { MessageBox.Show("The data insertion is failed", "Error", MessageBoxButtons.RetryCancel, MessageBoxIcon.Error); } }Ok, i got it. i found it somewhere on the internet. it did the job! Main m = (Main)Application.OpenForms["Main"]; m.bindComboBox();wolfcoder75, thank you for yr input. 这篇关于如何更新组合框，以便在将其添加到数据库后立即显示该记录？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！