dataGridView1.Rows.Add(gridRow);当控件被数据绑定时,无法以编程方式向 DataGrid 该怎么解决

Question

我是一名学生 最近在做一个课程设计 要求内容：
1、建立一个学生成绩管理系统数据库（一个学生信息表，一个学生成绩表，一个课程信息表）
2、对每个表都有增、删、改、查功能
3、对学生成绩有计算总分和平均分的功能
4、显示学生成绩表时，对成绩<60用红色字体显示
(1)60<=成绩<70  :显示1个星图标
(2)70<=成绩<80  :显示2个星图标
(3)80<=成绩<90  :显示3个星图标
(4)90<=成绩<100  :显示4个星图标
(5)成绩=100  :显示5个星图标
5、成绩<60,显示“补考”button,并实现“补考功能”（把相应成绩改为60以上）
成绩>60,显示“通过”button，并实现“通过”功能（统计该学生平均成绩);
 给怎么做学生成绩表的功能
//代码如下
public scmanage()
        {
            InitializeComponent();
            string str = "select * from tb_score";
            GetDB(str);
        }
 private void GetDB(string str)
        {
            
            con = new SqlConnection("Data Source=.;Initial Catalog=StuManage;Integrated Security=True");
            con.Open();
            cmd = new SqlCommand(str, con);
            sdr = new SqlDataAdapter();
            sdb = new SqlCommandBuilder(sdr);
            sdr.SelectCommand = cmd;
            ds = new DataSet();
            sdr.Fill(ds);
            DataTable te=ds.Tables[0];
            sdr.TableMappings.Add("tb_score", "tb_score");
            sdr.TableMappings[0].ColumnMappings.Add("sno", "学号");
            sdr.TableMappings[0].ColumnMappings.Add("sname", "姓名");
            sdr.TableMappings[0].ColumnMappings.Add("cname", "科目");
            sdr.TableMappings[0].ColumnMappings.Add("score", "成绩");
            ds.Tables[0].Columns["sno"].ColumnName = "学号";
            ds.Tables[0].Columns["sname"].ColumnName = "姓名";
            ds.Tables[0].Columns["cname"].ColumnName = "科目";
            ds.Tables[0].Columns["score"].ColumnName = "成绩";
            dataGridView1.DataSource = ds.Tables[0];
            data_Bind(ds.Tables["tb_score"]);
            con.Close();
   
        } public void data_Bind(DataTable table)
        {
            foreach (DataRow row1 in ds.Tables[0].Rows)
            {
                DataGridViewRow gridRow = new DataGridViewRow();
                
                DataGridViewButtonCell btn_cell = new DataGridViewButtonCell();
                DataGridViewTextBoxCell txt_star = new DataGridViewTextBoxCell();
                btn_cell.Value = "通过";
                for (int col_index = 0; col_index < ds.Tables[0].Columns.Count;col_index++ )
                {
                    DataGridViewTextBoxCell cell = new DataGridViewTextBoxCell();
                    cell.Value = row1[col_index];
                    gridRow.Cells.Add(cell);
                    
                    if (col_index == 5)
                    {
                        try
                        {
                            txt_star.Value = get_starPath(Convert.ToInt32(row1[5]));
                        }
                        catch { MessageBox.Show("图片不存在"); }
                        if (Convert.ToDecimal(row1[5]) < 60)
                        {
                            DataGridViewCellStyle cellStyle = new DataGridViewCellStyle();
                            cellStyle.ForeColor = Color.Red;
                            cell.Style = cellStyle;
                            btn_cell.Value = "补考";
                        }
                    }
                }
                gridRow.Cells.Add(txt_star);
                gridRow.Cells.Add(btn_cell);
                
                dataGridView1.Rows.Add(gridRow);
            }
        }
        public string get_starPath(int score)
        {
            int s = (score / 10);
            switch (s)
            {
                case 6: return " * ";
                case 7: return "* *";
                case 8: return "* * *";
                case 9: return "* * * *";
                case 10: return "* * * * *";
                default: return "";
            }
        }DataGridView编程控件

Answer 1

如果按照我这种绑定 该怎么实现3、对学生成绩有计算总分和平均分的功能
4、显示学生成绩表时，对成绩<60用红色字体显示
(1)60<=成绩<70  :显示1个星图标
(2)70<=成绩<80  :显示2个星图标
(3)80<=成绩<90  :显示3个星图标
(4)90<=成绩<100  :显示4个星图标
(5)成绩=100  :显示5个星图标
5、成绩<60,显示“补考”button,并实现“补考功能”（把相应成绩改为60以上）
成绩>60,显示“通过”button，并实现“通过”功能（统计该学生平均成绩);public scmanage()
        {
            InitializeComponent();
            string str = "select * from tb_score";
            GetDB(str);
        } private void GetDB(string str)
        {
            
            con = new SqlConnection("Data Source=.;Initial Catalog=StuManage;Integrated Security=True");
            con.Open();
            cmd = new SqlCommand(str, con);
            sdr = new SqlDataAdapter();
            sdb = new SqlCommandBuilder(sdr);
            sdr.SelectCommand = cmd;
            ds = new DataSet();
            sdr.Fill(ds);
            
            DataTable te=ds.Tables[0];
           
            sdr.TableMappings.Add("tb_score", "tb_score");
            sdr.TableMappings[0].ColumnMappings.Add("sno", "学号");
            sdr.TableMappings[0].ColumnMappings.Add("sname", "姓名");
            sdr.TableMappings[0].ColumnMappings.Add("cname", "科目");
            sdr.TableMappings[0].ColumnMappings.Add("score", "成绩");            ds.Tables[0].Columns["sno"].ColumnName = "学号";
            ds.Tables[0].Columns["sname"].ColumnName = "姓名";
            ds.Tables[0].Columns["cname"].ColumnName = "科目";
            ds.Tables[0].Columns["score"].ColumnName = "成绩";
            dataGridView1.DataSource = ds.Tables[0];
            DataGridViewButtonColumn col_btn_state = new DataGridViewButtonColumn();
            col_btn_state.HeaderText = "通过";
            col_btn_state.UseColumnTextForButtonValue = true;
            dataGridView1.Columns.Add(col_btn_state);
            
            con.Close();
            
        }

Answer 2

改成这样以后 怎么正确的显示上面所说的功能 让星型正常显示 补考和通过也正常显示
代码如下：
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.SqlClient;namespace WindowsFormsApplication1
{
    public partial class scmanage : Form
    {
        public SqlConnection con;
        public SqlDataAdapter sdr;
        public SqlCommandBuilder sdb;
        public SqlCommand cmd;
        public DataSet ds;
        public scmanage()
        {
            InitializeComponent();
            string str = "select * from tb_score";
            GetDB(str);
           
        }        private void btndele_Click(object sender, EventArgs e)
        {
            //MessageBox.Show("你点击了删除按钮");
            if (MessageBox.Show("确定要删除当前行数据？", "信息提示", MessageBoxButtons.OKCancel) == DialogResult.OK)
            {
                //此方法直接从数据库中删除在绑定数据库
                //string no = this.dataGridView1.Rows[e.RowIndex].Cells[3].Value.ToString();                //SqlConnection con = new SqlConnection("Data Source=.;Initial Catalog=StuManage;Integrated Security=True");
                //con.Open();                //SqlCommand cmd = new SqlCommand("delete  from tb_course where cno='" + no + "'", con);
                //int o = cmd.ExecuteNonQuery();
                //if (o > 0)
                //{
                //    MessageBox.Show("删除数据成功", "信息提示", MessageBoxButtons.OK);
                //}
                //else
                //{
                //    MessageBox.Show("删除数据不成功", "信息提示", MessageBoxButtons.OK);
                //}                //string str = "select * from tb_course";
                //GetDB(str);
                //此方法直接在绑定的数据源中删除并更新到数据库中
                try
                {
                    ds.Tables[0].Rows[dataGridView1.CurrentRow.Index].Delete();
                    sdr.Update(ds.Tables[0].GetChanges());
                    MessageBox.Show("数据删除成功");
                    ds.Tables[0].AcceptChanges();
                }
                catch (SqlException ex)
                {
                    MessageBox.Show(ex.ToString());
                }
            }
            else
            {
                MessageBox.Show("你点击了取消按钮");
            }
        }        private void btnup_Click(object sender, EventArgs e)
        {
            //MessageBox.Show("你点击了修改按钮");
            if (MessageBox.Show("确定要修改当前行数据？", "信息提示", MessageBoxButtons.OKCancel) == DialogResult.OK)
            {
                try
                {                    // sdr.Update(ds.Tables["tb_course"].GetChanges());
                    //cmd = new SqlCommand("update tb_course set cno='"+no+"',cname='"+name+"',ccredit='"+credit+"'",con);
                    //sdr.UpdateCommand = cmd;
                    //sdr.Update(ds.Tables[0]);
                    //sdb = new SqlCommandBuilder(sdr);
                    //sdr.Update(ds.Tables["tb_course"].GetChanges());
                    //sdr.Update(ds, "tb_course");
                    //sdr.Update(ds.Tables[0]);
                    //sdr.Update(ds.Tables["tb_sinfo"].GetChanges());                    sdr.Update(ds.Tables[0].GetChanges());
                    MessageBox.Show("数据修改成功");
                    // sdr.Update(ds.Tables[0].GetChanges());                    //ds.Tables[0].GetChanges();
                    ds.Tables[0].AcceptChanges();
                    //ds.Tables["tb_sinfo"].AcceptChanges();                }
                catch (SqlException ex)
                {
                    MessageBox.Show(ex.ToString());
                }
            }
        }        private void btninser_Click(object sender, EventArgs e)
        {
           // MessageBox.Show("你点击了增添按钮");
            if (MessageBox.Show("确定要增添当前行数据？", "信息提示", MessageBoxButtons.OKCancel) == DialogResult.OK)
            {
                try
                {                    //sdr.Update(ds.Tables[0]);
                    sdr.Update(ds.Tables[0].GetChanges());
                    MessageBox.Show("增加数据成功");
                    ds.Tables[0].AcceptChanges();
                }
                catch (SqlException ex)
                {
                    MessageBox.Show(ex.ToString());
                }
            }
        }        private void btnsele_Click(object sender, EventArgs e)
        {
                       if (comboBox1.Text == "学号")
            {
                string str = "select * from tb_score where sno='" + textBox1.Text.Trim() + "'";
                GetDB(str);
            }
            if (comboBox1.Text == "姓名")
            {
                string str = "select * from tb_score where sname='" + textBox1.Text.Trim() + "'";
                GetDB(str);            }
            if (comboBox1.Text == "成绩")
            {
                string str = "select * from tb_score where score='"+textBox1.Text.Trim()+"'";
                GetDB(str);
 
            }
            if (comboBox1.Text == "科目")
            {
                string str = "select * from tb_score where cname='"+textBox1.Text.Trim()+"'";
                GetDB(str);
 
            }
            if (comboBox1.Text == "" || textBox1.Text == "")
            {                MessageBox.Show("请选择查询的方式并且在输入框中输入相应的查询信息", "查询提示");
                return;
            }
            
        }        private void GetDB(string str)
        {
            
            con = new SqlConnection("Data Source=.;Initial Catalog=StuManage;Integrated Security=True");
            con.Open();
            cmd = new SqlCommand(str, con);
            sdr = new SqlDataAdapter();
            sdb = new SqlCommandBuilder(sdr);
            sdr.SelectCommand = cmd;
            ds = new DataSet();
            sdr.Fill(ds);
            DataTable te=ds.Tables[0];            sdr.TableMappings.Add("tb_score", "tb_score");
            sdr.TableMappings[0].ColumnMappings.Add("sno", "学号");
            sdr.TableMappings[0].ColumnMappings.Add("sname", "姓名");
            sdr.TableMappings[0].ColumnMappings.Add("cname", "科目");
            sdr.TableMappings[0].ColumnMappings.Add("score", "成绩");            ds.Tables[0].Columns["sno"].ColumnName = "学号";
            ds.Tables[0].Columns["sname"].ColumnName = "姓名";
            ds.Tables[0].Columns["cname"].ColumnName = "科目";
            ds.Tables[0].Columns["score"].ColumnName = "成绩";
            dataGridView1.DataSource = ds.Tables[0];
            DataGridViewButtonColumn col_btn_st = new DataGridViewButtonColumn();
            col_btn_st.HeaderText = "状态";            col_btn_st.UseColumnTextForButtonValue = true;
            dataGridView1.Columns.Add(col_btn_st);            DataGridViewButtonColumn col_btn_state = new DataGridViewButtonColumn();
            col_btn_state.HeaderText = "等级";
            col_btn_state.UseColumnTextForButtonValue = true;
            dataGridView1.Columns.Add(col_btn_state);
            foreach (DataRow row1 in ds.Tables[0].Rows)
            { //通过和补考不能正常显示
                for (int col_index = 0; col_index < ds.Tables[0].Columns.Count; col_index++)
                {
                 if (col_index == 3)
                    {
                        try
                        {
                            //调用显示星型的函数时 星型不能正常显示
                            col_btn_st.Text = get_starPath(Convert.ToInt32(row1[3]));                        }
                        catch { MessageBox.Show("图片不存在"); }
                        if (Convert.ToDecimal(row1[3]) < 60)
                        {
                             DataGridViewCellStyle cellStyle = new DataGridViewCellStyle();
                             cellStyle.ForeColor = Color.Red;
                           col_btn_state.Text = "补考";                        }
                        if (Convert.ToDecimal(row1[3]) >= 60)
                        {
                            col_btn_state.Text = "通过";
                        }
                    }
                }            }
            con.Close();   
        }
        private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
        {  //违反主键约束
            string id=dataGridView1.Rows[e.RowIndex].Cells[2].Value.ToString();
            //if (dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Value.ToString() == "补考")
            if (dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Value.ToString() == "通过")
            {
                con = new SqlConnection("Data Source=.;Initial Catalog=StuManage;Integrated Security=True");
                con.Open();
                cmd = new SqlCommand("update tb_score set score='" + 60 + "' where sno='" + id + "'", con);
                //object o = cmd.ExecuteScalar();
                int o = cmd.ExecuteNonQuery();
                if (o > 0)
                {
                    //if(cmd.ExecuteNonQuery()==1)
                    MessageBox.Show("成功！");
                }
                con.Close();
                //init_grid();
                string str = "select * from tb_score";
                GetDB(str);
            }
        }        public string get_starPath(int score)
        {
            int s = (score / 10);
            switch (s)
            {
                    //星型不能正常显示
                case 6: return " * ";
                case 7: return "* *";
                case 8: return "* * *";
                case 9: return "* * * *";
                case 10: return "* * * * *";
                default: return "";
            }
        }
           }}