Hide parts of the page while printing

first of all create a css as follows

style type="text/css" media="print">
.NonPrintable
{
display: none;
}

/style>

then use class name to NonPrintable to the element which You don't want to print on the paper

In the print style sheet, you can also hide other elements like your menu, header, footer or whatever it is you don't want to be printed:

.NonPrintable, #Menu, #Footer
{
display: none;
}

For detail see this article

Selecting or filtering value from DataSet

Suppose we have a District table having fields
District_Key
District_Name
District_StateKey
.....
.....

and have all the values in a dataset

DataSet dsState;

now we want to filter those value whoes state id is 4;
then we we can easily filter those value

DataRow[] dr = dsState.Tables[0].Select("State_Key=4");

Merging cells of a GridView

Suppose that we have a GridView data like this

Main Item	subItem	price
item1	s1	123
item1	s2	456
item 2	s1	878
item2	s2	456
item 2	s3	1231

And we want to create like this

Main Item	sub Item	price
item1	s1	123
	s2	456
item 2	s1	878
	s2	456
	s3	1231

Then we can get it by using the following code

protected void GridView1_DataBound(object sender, EventArgs e)
{
string text = "";
int count = 0;
Hashtable ht = new Hashtable();

// loop through all rows to get row counts
foreach (GridViewRow gvr in GridView1.Rows)
{
if (gvr.RowType == DataControlRowType.DataRow)
{
if (gvr.Cells[0].Text == text)
{
count++;
}
else
{
if (count > 0)
{
ht.Add(text, count);
}
text = gvr.Cells[0].Text;
count = 1;
}
}
}

if (count > 1)
{
ht.Add(text, count);
}


// loop through all rows again to set rowspan
text = "";
foreach (GridViewRow gvr in GridView1.Rows)
{
if (gvr.RowType == DataControlRowType.DataRow)
{
if (gvr.Cells[0].Text == text)
{
gvr.Cells.Remove(gvr.Cells[0]);
}
else
{
text = gvr.Cells[0].Text;
gvr.Cells[0].RowSpan = Convert.ToInt32(ht[text]);
}
}
}
}

To get the number of pixel taken by a string using Graphics in C#

Bitmap myImage;
Graphics g;
myImage = new Bitmap(760, 800, PixelFormat.Format32bppRgb);
g = Graphics.FromImage(myImage);


SizeF size = g.MeasureString("shekhar", new Font("Arial", 8));
int lenght = (int)size.Width;
int height1 = (int)size.Height;

this will give the length and height in pixel of the string "shekhar"

Parent Child Relation between two dropdown in a gridview

To change the drop down value form the other dropdown selected index change.

protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
GridViewRow row = (GridViewRow)((sender) as Control).NamingContainer;
DropDownList dr = (DropDownList)sender;
//DropDownList dr = (DropDownList)GridView1.FindControl("DropDownList1");

DropDownList dropdown2 =(DropDownList)row.FindControl("DropDownList2");
string condition = dr.SelectedValue.ToString();
SelectSubCategory(condition,dropdown2);//a function for filling the child gridview
}

GridView Changing the row style

If you want to change the style of row or column of a gridview then it can be done in the following way

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType ==DataControlRowType.DataRow)
{
for (int i = 2; i < e.Row.Cells.Count; i++)
{
e.Row.Cells[i].Style.Add("text-align", "right");
//e.Row.Cells[e.Row.Cells.Count-1].Text = "" + e.Row.Cells[i].Text + "";
}
}
}