如何将 DataGridView 格式化为密码字符？

Question

Goal:

My goal is to format 1 column to password characters * .

Resources I have tried:

I have used an example from here :

https://docs.microsoft.com/en-us/dotnet/api/system.windows.forms.datagridview.cellformatting?view=netframework-4.8

and tried this answer here:

https://stackoverflow.com/a/38074239/12485722

This is my current code to load DataGrid View:

private void Form3_Load(object sender, EventArgs e)
{
    RefreshGrid();
}



//Refresh Data Grid from external Forms
public void RefreshGrid()
{
    // MySQL connection string
    using (var conn = new MySqlConnection(ConnectionString()))
    {
        using (var mySqlDataAdapter = new MySqlDataAdapter("select * from user", conn))
        {
            using (var dataSet = new DataSet())
            {
                DataSet DS = new DataSet();
                mySqlDataAdapter.Fill(DS);
                dataGridView1.DataSource = DS.Tables[0];
            }
        }
    }
}

This simply loads up the DataGridView with Usernames and passwords.

Now I need to format 2nd column to password characters, so the passwords do not show as text but formatted as * .

I have tried adding this piece of code from the 2nd resource mentioned above:

private void dataGridView1_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
{
    if (e.ColumnIndex == 1 && e.Value != null)
    {
        e.Value = new String('*', e.Value.ToString().Length);
    }
}

This does not work - no errors show up, but I have noticed this references is set to 0.

(Note: this is what it should be)

Question:

I am confused where it is going wrong.. can somebody assist me to achieve this task?

Update (1) - Events and cell formatting not showing:

Answer 1

Your method is not wired to an event of GridView (thats why it has 0 references, because nothing is using your function).

The solution in the mentioned link is correct, but you should wire your method to an event in designer (right click on grid view > properties > events) and choose an event to fire up in CellFormatting event. Also dont forget to handle EditingControlShowing, but everything what you need is already written in a solution thread that you mentioned.

Answer 2

你为什么不修改你的查询，只说以下内容：

select username, repeat('*', length(password)) from users