dataGridView数据绑定及使用方法+索引超出范围

因为是三层架构,所以先在Dal层,将数据放入DataTable中先

public DataTable dataGrid(string UserName)
        {
            string sql = string.Format("SELECT * FROM demoUsers WHERE UserName=@UserName");
            Class1 q = new Class1(cc);
            ArrayList paramlist = new ArrayList();
            paramlist.Add(q.CreateParameter("@UserName", UserName, DbType.String, 50));
            IDataParameter[] param = (IDataParameter[])paramlist.ToArray(typeof(IDataParameter));
            return q.testDataTable(sql, param);
        }

所需要的实体对象,Mod都已经有了,在dataGridView任务中添加自己想要显示出来的数据,设置好后,UI代码

        private void WorkerBasicMessage_Load(object sender, EventArgs e)
        {
            dataGridView1.AutoGenerateColumns = false;//不需要的数据不选
        }

        private void button1_Click(object sender, EventArgs e)
        {

            string userName;
            SqlHelper ds = new SqlHelper();
            if (true)
            {
                userName = textBox1.Text.Trim();
            }
            DataTable dt = ds.dataGrid(userName);//将Id传进去得到一个数据表
            dataGridView1.DataSource = dt;
         }

数据名要跟数据中对应,如下图加黑的UserId

 

//联表查询统计所有记录group by sql语句运用
        public DataTable selectAllMessage()
        { 
            string sql = string.Format("select demoUsers.TrueName,COUNT (leaveMessage.UserId)as 请假次数 from demoUsers inner join leaveMessage on demoUsers.UserId=leaveMessage.UserId group by demoUsers.TrueName");
            DataConn conn = new DataConn(conStr);
            ArrayList paramlist = new ArrayList();
            IDataParameter[] param = (IDataParameter[])paramlist.ToArray(typeof(IDataParameter));
            return conn.testDataTable(sql, param);
        }

点击控件的记录显示详细数据的话,可设计单击事件CellClick

 datagridview 索引超出范围。必须为非负值并小于集合大小

 private void dGV1_CellClick(object sender, DataGridViewCellEventArgs e)
        {
            this.radioButton2.Checked = true;
            int currentRowIndex = dGV1.CurrentCell.RowIndex;
            if (currentRowIndex >= 0)
            {
                this.label6.Text = Convert.ToString(dGV1[0, currentRowIndex].Value).Trim();//显示编号
                this.label4.Text = Convert.ToString(dGV1[1, currentRowIndex].Value).Trim();//显示标题
                this.textBox1.Text = Convert.ToString(dGV1[3, currentRowIndex].Value).Trim();//问题描述
                this.textBox3.Text = Convert.ToString(dGV1[5, currentRowIndex].Value).Trim();//解决方法描述
                if (Convert.ToString(dGV1[6, currentRowIndex].Value).Trim() == "已解决")
                {
                    this.radioButton1.Checked = true;
                }
            }
        }