dataGridView_关于如何解决无法将类型“void”隐式转换为“System.Data.Datatabel”

一、原码如下： 

private void GetData()                                                                                                       //取数据
        {
            try
            {
                String cs = "Persist Security Info=false;User id=sa;pwd=;database=school;server=localhost";
                SqlConnection mycon = new SqlConnection();
                mycon.ConnectionString = cs;
                mycon.Open();
                SqlCommand scmd = new SqlCommand("Select Top 3 id,name from student", mycon);
                this.DA = new SqlDataAdapter();
                DA.SelectCommand = scmd;
                SqlCommandBuilder mycmdb = new SqlCommandBuilder(DA);
                this.DT.Clear();
                DA.Fill(this.DT);
               
            }
            catch (SqlException e)
            {
                MessageBox.Show("查询数据出错：" + e.Message);
            }
        
        }
        private void binddata()
        {
          DataTable dt = this.GetData();                                                                   //调试时出错的地方
          this.dataGridView1.DataSource = dt;
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            this.binddata();

        }    

 

二、错误信息提示：

错误 1 ：无法将类型“void”隐式转换为“System.Data.DataTable”

---

三、解决办法：

只需修改 GetData()函数：注意蓝色字

private DataTable GetData()                                                                                                       //取数据
        {
            try
            {
                String cs = "Persist Security Info=false;User id=sa;pwd=;database=school;server=localhost";
                SqlConnection mycon = new SqlConnection();
                mycon.ConnectionString = cs;
                mycon.Open();
                SqlCommand scmd = new SqlCommand("Select Top 3 id,name from student", mycon);
                this.DA = new SqlDataAdapter();
                DA.SelectCommand = scmd;
                SqlCommandBuilder mycmdb = new SqlCommandBuilder(DA);
                this.DT.Clear();
                DA.Fill(this.DT);
               
            }
            catch (SqlException e)
            {
                MessageBox.Show("查询数据出错：" + e.Message);
            }
            return DT;
        }