在winform中用Datatable模拟数据库做简单的增删改查

//简单的建一个表
private void FormDT_Load(object sender, EventArgs e)
        {
            dt.Columns.Add("A", typeof(String));
            dt.Columns.Add("B", typeof(String));
            dt.Columns.Add("C", typeof(String));
            dt.Rows.Add("101", "102", "103");
            dt.Rows.Add("100", "102", "103");
            dt.Rows.Add("111", "102", "104");
            this.dataGridView1.DataSource = dt;
            this.dataGridView1.AutoGenerateColumns = false;
        }

//添加
private void button1_Click(object sender, EventArgs e)
        {
            DataRow dr = dt.NewRow();
            dr["A"] = textBox1.Text;
            dr["B"] = textBox2.Text;
            dr["C"] = textBox3.Text;
            if (textBox1.Text == "" || textBox2.Text == "" || textBox3.Text == "")
            {
                MessageBox.Show("请完整填写数据");
                if (textBox3.Text == "")
                {
                    textBox3.Focus();
                }
                if (textBox2.Text=="")
                {
                    textBox2.Focus();
                }
                if (textBox1.Text=="")
                {
                    textBox1.Focus();                    
                }
            }
            else
            {
                dt.Rows.Add(dr); 
            }
            
        }

//修改，if里是非空验证和设置鼠标焦点
private void button2_Click(object sender, EventArgs e)
        {
            if (textBox1.Text == "" || textBox2.Text == "" || textBox3.Text == "")
            {
                MessageBox.Show("请完整填写数据");
                if (textBox3.Text == "")
                {
                    textBox3.Focus();
                }
                if (textBox2.Text == "")
                {
                    textBox2.Focus();
                }
                if (textBox1.Text == "")
                {
                    textBox1.Focus();
                }
            }
            else
            {
                DataRow dr = dt.Rows[dataGridView1.CurrentCell.RowIndex];
                dr.BeginEdit();
                dr["A"] = textBox1.Text;
                dr["B"] = textBox2.Text;
                dr["C"] = textBox3.Text;
                dr.EndEdit(); 
            }
        }

//删除，非空验证和修改里的差不多
private void button3_Click(object sender, EventArgs e)
        {
            double sum = 0;
            for (int i = 0; i < dataGridView1.Rows.Count; i++)
            {
                sum += Convert.ToDouble(dataGridView1.Rows[i].Cells[2].Value);
            }
            
            if (sum == 0)
            {
                MessageBox.Show("数据已经为空");
            }
            else
            {
                dt.Rows.RemoveAt(dataGridView1.CurrentCell.RowIndex);
            }
        }

运行之后，这个是运行后的初始样子。过两天我会发一个更详细的，多窗体的用datatable的做的小东西，看我首页随笔就行了