从 datagraidview 获取 null 时如何避免错误

Question

这里我需要避免来自datagridview (winform)的null

 private void SendUpdate()
        {
            
            if ((string)dataGridView1.SelectedRows[0].Cells[0].Value != string.Empty )
            {
                if (1 == dataGridView1.SelectedRows.Count)
                {
                    int Id = Convert.ToInt32(dataGridView1.SelectedRows[0].Cells[0].Value);
                    Update up = new Update();
                    up.AssignValue(Id);
                    up.textBox1.Text = dataGridView1.SelectedRows[0].Cells[1].Value.ToString();
                    up.comboBox1.Text = dataGridView1.SelectedRows[0].Cells[2].Value.ToString();
                    up.textBox2.Text = dataGridView1.SelectedRows[0].Cells[3].Value.ToString();
                    up.textBox3.Text = dataGridView1.SelectedRows[0].Cells[4].Value.ToString();
                    up.textBox4.Text = dataGridView1.SelectedRows[0].Cells[5].Value.ToString();
                    up.textBox5.Text = dataGridView1.SelectedRows[0].Cells[6].Value.ToString();
                    up.ShowDialog();
                }
                else
                {
                    MessageBox.Show("Please Select the Single Data Which Required to Update");
                }
            }
            else 
            {

                MessageBox.Show("You Select the empty Row");

            }
            
        }

我试过 !=string.empty; , !=null; , !=""; 但错误未解决。

1 == dataGridView1.SelectedRows.Count 是的

但是

(string)dataGridView1.SelectedRows[0].Cells[0].Value 有空值显示错误

System.NullReferenceException: 'Object reference not set to an instance of an object.'

System.Windows.Forms.DataGridViewCell.Value.get returned null.

Answer 1

 private void SendUpdate()
        {

            if (String.IsNullOrWhiteSpace(dataGridView1.SelectedRows[0].Cells[0].Value as string))
            {
                MessageBox.Show("You Select the empty Row");
            }
}

不工作它消除了所有具有数据的偶数行

从 datagraidview 获取 null 时如何避免错误

How avoid error when get null from datagraidview

c#

visual-studio-2012