如何防止datagridview在单元格中允许null [英] how to prevent datagridview to allow null in cells

问题描述

当我从datagridview输入数据到数据库时，它也允许null ..但我想阻止空值从gridview.in gridview输入数据库我采取有3列的文本框：id，name和city.if i输入id和city，datagridview允许并且不会给出任何错误。所以我的问题是如果用户将单元格设置为空白datagridview不允许用户移动下一个单元格直到该单元格中的用户输入

我尝试过一些代码但不起作用：

when i enter data from datagridview to database it also allow null..but i wanted to prevent null value to enter in the database from gridview.in gridview i take textboxes that have 3 columns:id,name and city.if i enter id and city,datagridview allow that and does not give any error.so my question is if user put the cells blank datagridview does not allow user to move next cell untill user input in that cells
I tried some code but not work like:

private void dataGridView1_CellValidating(object sender, DataGridViewCellValidatingEventArgs e)
        {
            int i = dataGridView1.Rows.Count;
            for (int j = 0; j < i; j++)
            {


                if (dataGridView1.Rows[j].Cells[0].Value == null)
                {
                    MessageBox.Show("Field 1 is empty");
                }
                else if(dataGridView1.Rows[j].Cells[2].Value == null)
                {
                    MessageBox.Show("Field 2 is empty");

                }
                else if (dataGridView1.Rows[j].Cells[2].Value == null)
                {
                    MessageBox.Show("Field 3 is empty");

                }

            }

        }

推荐答案

这是一个完整的解决方案：如何：验证Windows窗体中的数据DataGridView控件 [ ^ ]

Here is a complete solution: How to: Validate Data in the Windows Forms DataGridView Control[^]

private void dataGridView1_CellValidating(object sender,
    DataGridViewCellValidatingEventArgs e)
{
    // Validate the CompanyName entry by disallowing empty strings.
    if (dataGridView1.Columns[e.ColumnIndex].Name == "CompanyName")
    {
        if (String.IsNullOrEmpty(e.FormattedValue.ToString()))
        {
            dataGridView1.Rows[e.RowIndex].ErrorText =
                "Company Name must not be empty";
            e.Cancel = true;
        }
    }
}

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