解决DataGridView非连续勾选复选框时仅首个选中行创建触发器问题

你当前的代码核心错误是未选中提示和return语句的位置错误，它被放在了foreach遍历循环内部：

• 不管当前遍历的行是否为选中状态，只要第一次循环执行完成，就会直接弹出提示并结束整个方法，后续所有行都不会被遍历
• 你遇到的「连续选中前2行可以生效」属于巧合，大概率是你之前修改代码时缩进错误导致的偶发现象，本质逻辑上只能处理第一行符合条件的数据

1. 新增选中行计数器，统计所有被勾选的行数量
2. 将未选中提示和return逻辑移到foreach循环外部，只有当计数器为0（没有任何行被勾选）时才触发提示
3. 新增CheckBox值空校验，避免空值导致转换报错
4. 去掉多余的return逻辑，保证所有选中行都能被遍历处理

public void crear_trigger1()
{
    try
    {
        // 新增计数器，统计选中的行数
        int checkedRowCount = 0;
        
        foreach (DataGridViewRow r_tabla in dataGridView1.Rows)
        {
            // 做空值判断，避免CheckBox未赋值时转换报错
            bool isChecked = r_tabla.Cells[0].Value != null && Convert.ToBoolean(r_tabla.Cells[0].Value);
            if (isChecked)
            {
                checkedRowCount++;
                string creacion_tri_in = "";
                string creacion_tri_Up = "";
                string creacion_tri_eli = "";
                string columnas_orig = "";
                campos_tablas = new DataTable();
                campos_tablas = Traer_informacion("SELECT  COL.name AS columna,TYP.name AS Tipo, Longitud = CASE TYP.name  WHEN 'nvarchar' THEN COL.LENGTH/2 WHEN 'varchar' THEN COL.LENGTH/2 ELSE COL.LENGTH END  FROM dbo.syscolumns COL JOIN dbo.sysobjects OBJ ON OBJ.id = COL.id JOIN dbo.systypes TYP ON TYP.xusertype = COL.xtype  LEFT JOIN dbo.sysforeignkeys FK ON FK.fkey = COL.colid AND FK.fkeyid=OBJ.id  LEFT JOIN dbo.sysobjects OBJ2 ON OBJ2.id = FK.rkeyid  LEFT JOIN dbo.syscolumns COL2 ON COL2.colid = FK.rkey AND COL2.id = OBJ2.id   WHERE OBJ.name =  '" + r_tabla.Cells[1].Value.ToString() + "' AND (OBJ.xtype='U' OR OBJ.xtype='V') and COL.colstat!=1 group by  COL.name ,TYP.name, COL.LENGTH ", set_getcadena_orginen);
                creacion_tri_in = "CREATE TRIGGER  [dbo].[Tr_insertarLog_" + r_tabla.Cells[1].Value.ToString() + "] On [" + set_getbase_orginen + "].[dbo].[" + r_tabla.Cells[1].Value.ToString() + "] AFTER  insert AS DECLARE @ipPC VARCHAR(50) SET @ipPC = (SELECT client_net_address FROM sys.dm_exec_connections WHERE session_id = @@spid group by client_net_address)   SET ANSI_WARNINGS  OFF;";
                creacion_tri_Up = "CREATE TRIGGER  [dbo].[Tr_ActualizarLog_" + r_tabla.Cells[1].Value.ToString() + "] On [" + set_getbase_orginen + "].[dbo].[" + r_tabla.Cells[1].Value.ToString() + "] AFTER  update AS DECLARE @ipPC VARCHAR(50) SET @ipPC = (SELECT client_net_address FROM sys.dm_exec_connections WHERE session_id = @@spid  group by client_net_address)  SET ANSI_WARNINGS  OFF; ";
                creacion_tri_eli = "CREATE TRIGGER  [dbo].[Tr_EliminarLog_" + r_tabla.Cells[1].Value.ToString() + "] On [" + set_getbase_orginen + "].[dbo].[" + r_tabla.Cells[1].Value.ToString() + "] AFTER  delete AS DECLARE @ipPC VARCHAR(50) SET @ipPC = (SELECT client_net_address FROM sys.dm_exec_connections WHERE session_id = @@spid  group by client_net_address)  SET ANSI_WARNINGS  OFF;";
                for (int j = 0; j < campos_tablas.Rows.Count; j++)
                {
                    if (j == campos_tablas.Rows.Count - 1)
                    {
                        columnas_orig += "" + campos_tablas.Rows[j]["columna"].ToString() + " ";
                    }
                    else if (j < campos_tablas.Rows.Count - 1)
                    {
                        columnas_orig += "" + campos_tablas.Rows[j]["columna"].ToString() + ",";
                    }
                }
                //TRIGGER INSERT
                creacion_tri_in += "insert into " + set_getbase_destino + ".[dbo].[" + r_tabla.Cells[1].Value.ToString() + "] (" + columnas_orig + " ,[TRANSACCION1],   [FECHATRANSACCION1] ,   [USUARIOTRANSACCION1] , [ipPC1] ,C_ejecutada,Puesto_T) (select top 1 " + columnas_orig + ", 'INSERCION' AS transaccion,getdate() as FECHATRANSACCION,SUSER_SNAME() as USUARIOTRANSACCION ,@ipPC ,(SELECT  details.text FROM    sys.dm_exec_requests requests CROSS APPLY sys.dm_exec_sql_text (requests.plan_handle) details WHERE   requests.session_id > 50) ,HOST_NAME()  as esta FROM INSERTED ) SET ANSI_WARNINGS ON; ";
                Ejectar_consultas(creacion_tri_in, set_getcadena_orginen);
                //TRIGGER UPDATE 
                creacion_tri_Up += "insert into " + set_getbase_destino + ".[dbo].[" + r_tabla.Cells[1].Value.ToString() + "] (" + columnas_orig + " ,[TRANSACCION1] ,  [FECHATRANSACCION1] ,   [USUARIOTRANSACCION1] , [ipPC1],C_ejecutada ,Puesto_T) (select top 1 " + columnas_orig + ", 'ACTUALLIZACION' AS transaccion,getdate() as FECHATRANSACCION,SUSER_SNAME() as USUARIOTRANSACCION ,@ipPC ,(SELECT  details.text FROM    sys.dm_exec_requests requests CROSS APPLY sys.dm_exec_sql_text (requests.plan_handle) details WHERE   requests.session_id > 50 ),HOST_NAME()  as esta  FROM INSERTED )SET ANSI_WARNINGS ON;";
                Ejectar_consultas(creacion_tri_Up, set_getcadena_orginen);
                //TRIGGER DELETE
                creacion_tri_eli += "insert into " + set_getbase_destino + ".[dbo].[" + r_tabla.Cells[1].Value.ToString() + "] (" + columnas_orig + ",[TRANSACCION1] ,  [FECHATRANSACCION1] ,   [USUARIOTRANSACCION1] , [ipPC1],C_ejecutada,Puesto_T ) (select top 1 " + columnas_orig + ", 'ELIMINACION' AS transaccion,getdate() as FECHATRANSACCION,SUSER_SNAME() as USUARIOTRANSACCION ,@ipPC ,(SELECT  details.text FROM    sys.dm_exec_requests requests CROSS APPLY sys.dm_exec_sql_text (requests.plan_handle) details WHERE   requests.session_id > 50  ) ,HOST_NAME()  as esta  FROM DELETED)SET ANSI_WARNINGS ON; ";
                Ejectar_consultas(creacion_tri_eli, set_getcadena_orginen);
            }
        }

        // 遍历完所有行之后再判断是否有选中的行
        if (checkedRowCount == 0)
        {
            MessageBox.Show("You must select the rows");
            return;
        }
        // 可选：加成功提示
        MessageBox.Show($"已为{checkedRowCount}张表成功创建触发器");
    }
    catch (Exception ex)
    {
        set_geterror = ex.Message;
        return;
    }
}

• 建议对拼接SQL的表名参数做校验，避免拼写错误或SQL注入风险
• 可以新增触发器存在性判断，创建前先删除已存在的同名触发器，避免重复创建报错

内容的提问来源于stack exchange，提问作者Esteban Giraldo