c# Excel导入 问题求解

Question

 private void btnChoose_Click(object sender, EventArgs e)
        {
            this.openFileDialog1.ShowDialog();
            this.txtfilepath.Text = this.openFileDialog1.FileName;
            filePath = this.txtfilepath.Text;
        }        private void btnLeadin_Click(object sender, EventArgs e)
        {
            if(filePath.Trim()=="")
            {
                MessageBox.Show("请先选取要导入的 Excel表格","提示信息",MessageBoxButtons.OK,MessageBoxIcon.Information);
                return;
            }
            //string strConn = "Provider=Microsoft.Jet.Oledb.4.0;Data Source=" + Dir + "\\" + fileName + ";Extended Properties='Excel 8.0;HDR=Yes;IMEX=1;'";
            string connect = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source =" + filePath + ";Extended Properties='Excel 8.0;IMEX=1;HDR=Yes;'";
            OleDbConnection cnnxls = new OleDbConnection(connect);
            OleDbDataAdapter dbAdapter = new OleDbDataAdapter("select * from [sheet1$]",cnnxls) ;            DataSet dsTarget = new DataSet();
            dbAdapter.Fill(dsTarget);
            
            this.dataGridView1.DataSource = dsTarget.Tables[0];            this.dataGridView1.Columns[0].Width = 60;
            this.dataGridView1.Columns[1].Width = 80;
            this.dataGridView1.Columns[2].Width = 60;
            this.dataGridView1.Columns[3].Width = 60;
                    }        private void btnSave_Click(object sender, EventArgs e)
        {
            try
            {
                for (int i = 0; i < this.dataGridView1.Rows.Count; i++)
                {
                    No = "";
                    name = "";
                    tel = "";
                    date = "";
                    if (this.dataGridView1.Rows[i].Cells[0].Value != null)
                    {
                        No = this.dataGridView1.Rows[i].Cells[0].Value.ToString();
                    }
                     if (this.dataGridView1.Rows[i].Cells[1].Value != null)
                    {
                        name = this.dataGridView1.Rows[i].Cells[1].Value.ToString();
                    }
                     if (this.dataGridView1.Rows[i].Cells[2].Value != null)
                    {
                       tel = this.dataGridView1.Rows[i].Cells[2].Value.ToString();
                    }
                    if (this.dataGridView1.Rows[i].Cells[3].Value != null)
                    {
                        date = this.dataGridView1.Rows[i].Cells[3].Value.ToString();
                    }
                                       sql = "insert into tb_matchplayer values('" + No + "','" + name + "','" + tel + "','" + date + "')";
                    dc.getcom(sql);
                }
                MessageBox.Show("导入数据成功", "提示信息", MessageBoxButtons.OK, MessageBoxIcon.Information);            }
            catch (Exception ex)
            {
                MessageBox.Show("导入数据失败，请检查Excel的格式是否标准", "提示信息", MessageBoxButtons.OK, MessageBoxIcon.Information);            }
        }在导入时 EXCEL格式正确时，提示导入失败时，却导入成功了；EXCEL格式不正确时，提示导入失败时，不能导入。不知是什么原因，求高手解答!

Answer 1

for循环里有一条错了吧，debug确定哪一条
另外，拼sql很容易出问题，用sql参数