How to create column of type password in gridview?

问题:

I am creating an application in which user selects files and provides credentials to open that file. For that I have created three columns in a gridview.
User enters password in password column.
I want to display * in place of characters like we can create a textbox of password type.
I have tried this code on GridView_CellClick event :

if (GridView.Columns[e.ColumnIndex].HeaderText == "Password")
{ 
   txtPassword[e.RowIndex] = new TextBox();
   txtPassword[e.RowIndex].Name = "txtPassword"+e.RowIndex;
   txtPassword[e.RowIndex].PasswordChar = '*';
   txtPassword[e.RowIndex].Visible = true;
   txtPassword[e.RowIndex].TextChanged += new      

   if (GridView.CurrentCell.Value == null)
      txtPassword[e.RowIndex].Text = "";
   else
      txtPassword[e.RowIndex].Text = GridView.CurrentCell.Value.ToString();

   txtPassword[e.RowIndex].Location = GridView.GetCellDisplayRectangle(e.ColumnIndex, e.RowIndex + 1, false).Location;

   txtPassword[e.RowIndex].Size = GridView.GetCellDisplayRectangle(e.ColumnIndex, e.RowIndex + 1, false).Size;

   txtPassword[e.RowIndex].Visible = true;
   txtPassword[e.RowIndex].Focus();
} 

But in above solution characters are displayed.
How can I solve this problem?

回答1:

I think it should work to handle the EditingControlShowing event and in the handler add the following code:

if(e.ColumnIndex == 2)
{
    TextBox tb = e.Control as TextBox;
    if (tb != null)
    {
        tb.PasswordChar = '*';
    }
}

CellFormatting Event Handler code:

if(e.ColumnIndex = 2)
{
    if(e.Value != null)
    {
        e.Value = New string("*", e.Value.ToString().Length);
    }
}

And in this event e should have a ColumnIndex property :)

回答2:

One solution would be to create your own type of cell and assign that type to your password column. For example you'll add only the standard TextBoxPassword to it and then it should work as you wish.

On the MSDN there is more detailed description with source code available.

You'll just have to create your won kind of CellTemplate.

回答3:

You can create a custom cell and column, and use a textbox with the password mask as your edit control.

To get around returning the clear text when you leave edit mode, you can store the actual password value in a seperate property of the cell, and in the GetFormattedValue event (i believe) you can return a string made up of entirely "*" characters to mask the regular display.

Protected Overrides Function GetFormattedValue(ByVal value As Object, ByVal rowIndex As Integer, ByRef cellStyle As System.Windows.Forms.DataGridViewCellStyle, ByVal valueTypeConverter As System.ComponentModel.TypeConverter, ByVal formattedValueTypeConverter As System.ComponentModel.TypeConverter, ByVal context As System.Windows.Forms.DataGridViewDataErrorContexts) As Object
        Dim strVal As String

        strVal = New String(CChar("*"), value.ToString.Length)

        Return MyBase.GetFormattedValue(strVal, rowIndex, cellStyle, valueTypeConverter, formattedValueTypeConverter, context)

    End Function
    Public Overrides Sub InitializeEditingControl(ByVal rowIndex As Integer, _
    ByVal initialFormattedValue As Object, ByVal dataGridViewCellStyle As DataGridViewCellStyle)

        MyBase.InitializeEditingControl(rowIndex, initialFormattedValue, _
                                        dataGridViewCellStyle)

        Dim ctl As PasswordTextBoxEditingControl = _
            CType(DataGridView.EditingControl, PasswordTextBoxEditingControl)

        If IsDBNull(Me.Value) Then
            ctl.Text = ""


        Else
            ctl.Text = CType(Me.Value, String)
            ctl.PasswordChar = "*"
            ctl.Mask = "*"
        End If

    End Sub

for more information on what you are trying to do, visit this: http://www.vbforums.com/showthread.php?t=554744