C# - 如何从 DataGridView 中删除选定的行？

Question

我正在尝试删除用户在 C# WinForms 应用程序的 DataGridView 中选择的行（连接到已经有记录的本地数据库）。

我已经实现了下面的代码，并且没有错误，但是删除从未被拾取（即使消息框显示一条记录已被“删除”，这是不正确的，因为该记录仍保留在 DataGrid 中）

另请注意，删除功能在搜索功能中 - 请参见下面的代码。

public void DisplayData()
    {
        string ConnectionString = @"Data Source=.\SQLEXPRESS;AttachDbFilename= C:\Program Files\Microsoft SQL Server\MSSQL14.SQLEXPRESS\MSSQL\DATA\Library System Project.mdf ;Integrated Security=True;Connect Timeout=30";

        string Query = "select * from Customers";

        SqlConnection DBCon = new SqlConnection(ConnectionString);
        SqlCommand DBCommand = new SqlCommand(Query, DBCon);
        SqlDataReader DBReader;

        try
        {
            DBCon.Open();
            DataTable dt = new DataTable();
            SqlDataAdapter da = new SqlDataAdapter(DBCommand);
            da.Fill(dt);
            dgv_CustomerDetails.DataSource = dt;
        }

        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }

        finally
        {
            // *** If you're going to be opening a connection be sure to close it ***
            // *** Finally blocks work well for this ***
            DBCon.Close();
        }
    }


    private void SearchCustomerRecordForm_Load(object sender, EventArgs e)
    {
        DisplayData();
    }


    private void btnDeleteCustomerRecord_Click(object sender, EventArgs e)
    {
        string ConnectionString = @"Data Source=.\SQLEXPRESS;AttachDbFilename= C:\Program Files\Microsoft SQL Server\MSSQL14.SQLEXPRESS\MSSQL\DATA\Library System Project.mdf ;Integrated Security=True;Connect Timeout=30";

        int rowIndex = dgv_CustomerDetails.CurrentCell.RowIndex;

        string Query = "delete from Customers where CustomerName = '"+ dgv_CustomerDetails.CurrentCell(rowIndex) +"'";

        SqlConnection DBCon = new SqlConnection(ConnectionString);
        SqlCommand DBCommand = new SqlCommand(Query, DBCon);
        SqlDataReader DBReader;

        try
        {
            DBCon.Open();
            DBReader = DBCommand.ExecuteReader();
            MessageBox.Show("Customer record removed from the system.", "Library System", MessageBoxButtons.OK);
        }

        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }

        finally
        {
            // *** If you're going to be opening a connection be sure to close it ***
            // *** Finally blocks work well for this ***
            DBCon.Close();
            DisplayData();
        }
    }

Answer 1

您确定查询创建良好吗？该行似乎缺少单元格值属性：

string Query = "delete from Customers where CustomerName = '"+ dgv_CustomerDetails.CurrentCell(rowIndex).value +"'";

尝试查看 Query 变量的值，因为它是建立起来的。