//新增
 private void button1_Click(object sender, EventArgs e)
 {
     Books book= new Books();
     book.BuyPrice = 10;
     book.BuyDate = DateTime.Now;
     currBook = book;
     button2.Enabled = true;
 }
        //点击网格
        private void dataGridView1_Click(object sender, EventArgs e)
        {
            if (dataGridView1.CurrentCell == null) return;

            int rowindex = dataGridView1.CurrentCell.RowIndex;
            DataTable dt = (DataTable)dataGridView1.DataSource;

            Books book = new Books();
            book.Id = Convert.ToInt32(dt.Rows[rowindex]["Id"]);
            book.BookName = dt.Rows[rowindex]["BookName"].ToString();
            book.BuyPrice = Convert.ToDecimal(dt.Rows[rowindex]["BuyPrice"]);
            book.BuyDate = Convert.ToDateTime(dt.Rows[rowindex]["BuyDate"]);
            book.Flag = Convert.ToInt32(dt.Rows[rowindex]["Flag"]);


            currBook = book;

        }