Comparing database values with values from a GridView

Question

I have a block of C# code here that stores data to an ArrayList from the database and compares each with the values from the GridView.

Is there a way to reduce the line of code and improve its readability?

 while (DataReader.Read())
{
 arrHostName.Add(DataReader.GetString(0));
 arrUsers.Add(DataReader.GetString(2));
 arrPSName.Add(DataReader.GetString(3));
} 
foreach (Infragistics.Win.UltraWinGrid.UltraGridRow row in Grid2.Rows)
{
 string rowHostName = row.Cells["HostName"].Value.ToString();
 string rowUsers = row.Cells["Users"].Value.ToString();
 string rowPSName= row.Cells["PS_NAME"].Value.ToString();
 foreach (string a in arrHostName)
 {
 if (rowHostName == a.ToString())
 { 
 row.Appearance.BackColor = Color.Yellow;
 row.Appearance.FontData.Bold = Infragistics.Win.DefaultableBoolean.True;
 }
 }
 foreach (string a in arrUsers)
 {
 if (rowUsers == a.ToString())
 {
 row.Appearance.BackColor = Color.Yellow;
 row.Appearance.FontData.Bold = Infragistics.Win.DefaultableBoolean.True;
 }
 }
 foreach (string a in arrPSName)
 {
 if (rowPSName == a.ToString())
 {
 row.Appearance.BackColor = Color.Yellow;
 row.Appearance.FontData.Bold = Infragistics.Win.DefaultableBoolean.True;
 }
 }
}

Answer 1

It looks like what you want is ArrayList.Contains.

string rowHostName = row.Cells["HostName"].Value.ToString();
string rowUsers = row.Cells["Users"].Value.ToString();
string rowPSName= row.Cells["PS_NAME"].Value.ToString();
if (arrHostName.Contains(rowHostName) 
 || arrUsers.Contains(rowUsers) 
 || arrPSName.Contains(rowPSName))
{ 
 row.Appearance.BackColor = Color.Yellow;
 row.Appearance.FontData.Bold = Infragistics.Win.DefaultableBoolean.True;
}

And if you only use the collections above to check if they contain some values, you should prefer HashSet over ArrayList.

Of course, you should then change the names of the local variables accordingly, from arrHostName to hostNames and so on. It is always better not to clutter variable names with type information in C#, whose type system is good enough.

Answer 2

for improvement, to reduce no of iterations

 foreach (Infragistics.Win.UltraWinGrid.UltraGridRow row in Grid2.Rows)
 {
 string rowHostName = row.Cells["HostName"].Value.ToString();
 string rowUsers = row.Cells["Users"].Value.ToString();
 string rowPSName= row.Cells["PS_NAME"].Value.ToString();
 foreach (string a in arrHostName)
 {
 if (rowHostName == a)
 { 
 row.Appearance.BackColor = Color.Yellow;
 row.Appearance.FontData.Bold = Infragistics.Win.DefaultableBoolean.True;
 goto Outer;
 }
 }
 foreach (string a in arrUsers)
 {
 if (rowUsers == a)
 {
 row.Appearance.BackColor = Color.Yellow;
 row.Appearance.FontData.Bold = Infragistics.Win.DefaultableBoolean.True;
 goto Outer;
 }
 }
 foreach (string a in arrPSName)
 {
 if (rowPSName == a)
 {
 row.Appearance.BackColor = Color.Yellow;
 row.Appearance.FontData.Bold = Infragistics.Win.DefaultableBoolean.True;
 goto Outer;
 }
 }
 Outer:
 continue;
 } 

And if all arraylist having same length, then you could reduce no of for loops

foreach (Infragistics.Win.UltraWinGrid.UltraGridRow row in Grid2.Rows)
 {
 string rowHostName = row.Cells["HostName"].Value.ToString();
 string rowUsers = row.Cells["Users"].Value.ToString();
 string rowPSName= row.Cells["PS_NAME"].Value.ToString();
 for (int i = 0; i < arrHostName.Length; i++)
 {
 if (arrHostName[i].ToString() == rowHostName || arrUsers[i].ToString() == rowUsers || arrPSName[i].ToString() == rowPSName)
 {
 row.Appearance.BackColor = Color.Yellow;
 row.Appearance.FontData.Bold = Infragistics.Win.DefaultableBoolean.True;
 break;
 }
 }
 } 

Edited

if (arrHostName[i] == rowHostName || arrUsers[i] == rowUsers || arrPSName[i] == rowPSName)

Updated

foreach (Infragistics.Win.UltraWinGrid.UltraGridRow row in Grid2.Rows)
 {
 string rowHostName = row.Cells["HostName"].Value.ToString();
 string rowUsers = row.Cells["Users"].Value.ToString();
 string rowPSName= row.Cells["PS_NAME"].Value.ToString();
 if(arrHostName.Contains(rowHostName) || arrUsers.Contains(rowUsers) || arrPSName.Contains(rowPSName))
 {
 row.Appearance.BackColor = Color.Yellow;
 row.Appearance.FontData.Bold = Infragistics.Win.DefaultableBoolean.True;
 }
 } 

Further improvement -- reduced more no of lines

foreach (Infragistics.Win.UltraWinGrid.UltraGridRow row in Grid2.Rows)
 {
 if(arrHostName.Contains(row.Cells["HostName"].Value.ToString()) || arrUsers.Contains(row.Cells["Users"].Value.ToString()) || arrPSName.Contains(row.Cells["PS_NAME"].Value.ToString()))
 {
 row.Appearance.BackColor = Color.Yellow;
 row.Appearance.FontData.Bold = Infragistics.Win.DefaultableBoolean.True;
 }
 } 

• vikas: the reason why I have added goto Outer; is- if you changes the back color of a row in first for, then there is no need to go to other for
• vikas: @QKWS length of arraylist are not same right? I mean all having same length or ?
• vikas: @QKWS arraylist length would be same as the no of rows coming from datareader right?
• vikas: @QKWS edited if logic, so It would work
• vikas: use Count instead of length

Answer 3

It would be best way to do this.

foreach (Infragistics.Win.UltraWinGrid.UltraGridRow row in Grid2.Rows)
 {
 if(arrHostName.Contains(row.Cells["HostName"].Value.ToString()) || arrUsers.Contains(row.Cells["Users"].Value.ToString()) || arrPSName.Contains(row.Cells["PS_NAME"].Value.ToString()))
 {
 row.Appearance.BackColor = Color.Yellow;
 row.Appearance.FontData.Bold = Infragistics.Win.DefaultableBoolean.True;
 }
 }