|
mtwal -> conditional formatting for datagrid cells (3/15/2008 1:19:06 AM)
|
Hi,
I am struggling with a problem of how to format datagrid cells based on criteria. I have seen an example in .net compact framework 2.0, but can't get it to work in 3.5. Does anyone have any experience with this?
I am trying to implement a class called ColumnStyle which inherits from DataGridTextBoxColumn. This is from an example I found.
private MainControl theControl;
private DBInterface db;
private Status theStatus;
private DataTable scenResults;
public frmStudents(MainControl con)
{
InitializeComponent();
theControl = con;
theStatus = theControl.GetStatus();
db = theControl.GetDBInterface();
BindDG();
}
private void BindDG()
{
CreateTableColumns();
ArrayList theStudents = db.StudentScenarioResults();
AddRows(theStudents);
dgStudents.DataSource = scenResults;
addGridStyle(ref dgStudents);
dgStudents.Refresh();
}
private void CreateTableColumns()
{
scenResults = new DataTable();
DataColumn dcol = new DataColumn("Student", typeof(System.String));
scenResults.Columns.Add(dcol);
ArrayList scenarios = db.GetScenarios();
foreach (Scenarios scen in scenarios)
{
string sName = scen.Name;
dcol = new DataColumn(sName, typeof(System.Int32));
scenResults.Columns.Add(dcol);
}
}
private void AddRows(ArrayList results)
{
//Add Rows to Data Table
}
private void addGridStyle(ref DataGrid dg)
{
//Datagrid Table Style is applied to the datagrid and contains
//the individual column styles
DataGridTableStyle dtStyle = new DataGridTableStyle();
dtStyle.MappingName = "scenResults";
for (int i = 0; i < scenResults.Columns.Count; i++)
{
ColumnStyle myStyle = new ColumnStyle(i);
myStyle.MappingName = scenResults.Columns.ColumnName;
if (scenResults.Columns.ColumnName == "Student")
myStyle.CheckSecondTest += new CheckCellEventHandler(myStyle_SecondTest);
//now add this instance of our ColumnStyle to the DataGridTableStyle
dtStyle.GridColumnStyles.Add(myStyle);
}
//add the datagridtablestyle to the datagrid
dg.TableStyles.Add(dtStyle);
}
public void myStyle_SecondTest(object sender, DataGridEnableEventArgs e)
{
//do something based on the row & column to set enable flag
//in this case see if we can cast the value to a double and if so
//check if its below zero
string name = (string)dgStudents[e.Row, e.Column];
e.MeetsCriteria = true;
}
public delegate void CheckCellEventHandler(object sender, DataGridEnableEventArgs e);
public class DataGridEnableEventArgs : EventArgs
{
private int _column;
private int _row;
private bool _meetsCriteria;
public DataGridEnableEventArgs(int row, int col, bool val)
{
_row = row;
_column = col;
_meetsCriteria = val;
}
public int Column
{
get { return _column; }
set { _column = value; }
}
public int Row
{
get { return _row; }
set { _row = value; }
}
public bool MeetsCriteria
{
get { return _meetsCriteria; }
set { _meetsCriteria = value; }
}
}
public class ColumnStyle : DataGridTextBoxColumn
{
public event CheckCellEventHandler CheckSecondTest;
public event CheckCellEventHandler CheckCellContains;
public event CheckCellEventHandler CheckCellEquals;
private int _col;
public ColumnStyle(int column)
{
_col = column;
}
protected override void Paint(Graphics g, Rectangle Bounds, CurrencyManager Source, int RowNum, Brush BackBrush, Brush ForeBrush, bool AlignToRight)
{
//can remove this if you don't want to vary the formatting on disabled cells
bool enabled = true;
//check if our event handler is not null for this cell and then signal the event
//the returning result in 'e' will contain a true or false boolean value
//the event can be 'receieved' anywhere in our program and the logic can be anything
// we choose. The method called from the event simply has to match our 'CheckCellEventHandler'
//delegate.
if (CheckSecondTest != null)
{
DataGridEnableEventArgs e = new DataGridEnableEventArgs(RowNum, _col, enabled);
CheckSecondTest(this, e);
if (e.MeetsCriteria)
BackBrush = new SolidBrush(Color.Orange);
}
//repeat again for our second event handler
if (CheckCellContains != null)
{
DataGridEnableEventArgs e = new DataGridEnableEventArgs(RowNum, _col, enabled);
CheckCellContains(this, e);
if (e.MeetsCriteria)
BackBrush = new SolidBrush(Color.PaleGreen);
}
base.Paint(g, Bounds, Source, RowNum, BackBrush, ForeBrush, AlignToRight);
//out third event handler , we are going to use this draw a rectangle around our
//cell so we call it after we have called the base class paint method
if (CheckCellEquals != null)
{
DataGridEnableEventArgs e = new DataGridEnableEventArgs(RowNum, _col, enabled);
CheckCellEquals(this, e);
if (e.MeetsCriteria)
g.DrawRectangle(new Pen(Color.Red, 2), Bounds.X + 1, Bounds.Y + 1, Bounds.Width - 2, Bounds.Height - 2);
}
}
}
The overridden OnPaint method of ColumnStyle is never called.
Thanks for any help you can provide,
Matt
|
|
|
|