Show message in empty cells in GridView

Question

I'm importing GridView from excel I need to show a message near every empty cell to give the user information about what it should be writing..

void simpleButton1_Click(object sender, System.EventArgs e)
{
    string[] msg = new string[60];
    string[] error = new string[400];
    for (int i = 0; i < gridView3.RowCount ; i++)
    {
        System.Data.DataRow Rows = gridView3.GetDataRow(i);
        string cellvalue = Rows[0].ToString();
        if (cellvalue == "")
        {
            msg[0] = "Missing 'First Name'";
            error[i] = msg[0] + " - ";  
        }   
        cellvalue = Rows[1].ToString();
        if (cellvalue == "")
        {
            msg[1] = "Missing 'Last Name'";
            error[i] += msg[1] + " - ";
        }
        //...
    }
}

How can I put the variable msg[] to the specific cell with a little image or "!" figure or maybe I can color the cell

Answer 1

Maybe you can use a ToolTip to show your alert:

toolTip1.ToolTipIcon = ToolTipIcon.Warning;
toolTip1.ToolTipTitle = "Warning!";
toolTip1.Show("Missing 'First Name'", x, y);

You only need to guess the location of the cell based on the sizes of the rows and columns of the DataGridView.

ToolTip is in System.Windows.Forms namespace.

Answer 2

You can color the XtraGrid cells using Conditional Formatting feature:

gridControl1.DataSource = new List<Person> { 
    new Person(){ Name = "John", Age = 25 },
    new Person(){ Name = "Mary", Age = 17 },
    new Person(){ Age = 17  },
    new Person(){ Name = "Ann" },
    new Person(){ Name = "Pit", Age = 5 },
};
StyleFormatCondition nameCondition = new StyleFormatCondition();
nameCondition.Column = gridView1.Columns["Name"];
nameCondition.Condition = FormatConditionEnum.Expression;
nameCondition.Expression = "IsNullOrEmpty([Name])";
nameCondition.Appearance.BackColor = Color.Red;
nameCondition.Appearance.Options.UseBackColor = true;

StyleFormatCondition ageCondition = new StyleFormatCondition();
ageCondition.Column = gridView1.Columns["Age"];
ageCondition.Condition = FormatConditionEnum.Expression;
ageCondition.Expression = "[Age]<10";
ageCondition.Appearance.BackColor = Color.Maroon;
ageCondition.Appearance.Options.UseBackColor = true;

gridView1.FormatConditions.AddRange(new StyleFormatCondition[] { 
    nameCondition, ageCondition
});

Result:

Related Links:
Customizing Appearances of Individual Rows and Cells
Style Format Conditions
Custom Painting (Samples)

Answer 3

Reference: How to: Provide Custom Display Text for Data Cells

To provide custom display text for data cells via the ColumnView.CustomColumnDisplayText event. To more information regarding customdrawing and cell styling go through Custom Painting Samples, Customizing Appearances of Individual Rows and Cells documentation section.

check the example empty strings are displayed within the "Discount" column's cells if they contain zero values.

using DevExpress.XtraGrid.Views.Base;

private void gridView1_CustomColumnDisplayText(object sender, 
CustomColumnDisplayTextEventArgs e) {
   if(e.Column.FieldName == "Discount")
      if(Convert.ToDecimal(e.Value) == 0) e.DisplayText = "";
}

If you want to show Image and text both then you need to handle the GridView.CustomDrawCell event of your GridView, here is a snip of code that change the color of the Name column, based on an other column valoe (age column)

private void gridView_CustomDrawCell(object sender, RowCellCustomDrawEventArgs e)
    {
        if (e.Column == colName)
        {
            var age = Convert.ToInt32(gridView.GetRowCellValue(e.RowHandle, colAge));
            if (age < 18)
                e.Appearance.BackColor = Color.FromArgb(0xFE, 0xDF, 0x98);
            else
                e.Appearance.BackColor = Color.FromArgb(0xD2, 0xFD, 0x91);
        }
    }

Answer 4

To change the color of cell

Rows[1].Interior.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red);