how to correctly build a formview dynamically/programmatically/code behind (did i do this

What i've written works(it does what it's being asked to do) but i was wondering if this is the correct way to programmatically bind and alter the formview
Reason: We have various needs that will need to be achieved like, various SQL statements, variables & rules... so i was needing more control over what the wizard provides...

So i was wondering if this way is the "Best practice" and etc..

**Also i gotta figure out how to keep it form inserting a row on "refresh button" & I couldn't get itemUpdated to work?

For brevity of code I'll post the ItemTemplate, which is replaced by EditItemTemplate or InsertItemTemplate with <%#Bind()%> on the Textboxes if necessary.

<asp:LabelID="lblError"runat="server"></asp:Label><br/>

<br/>

<asp:FormViewID="FormView1"runat="server"OnModeChanging="FormView1_ModeChanging"OnItemUpdating="FormView1_ItemUpdating"DataKeyNames="RowID"OnItemInserting="FormView1_ItemInserting">

<ItemTemplate>
<tablestyle="width: 338px; height: 264px">

<tr>
<tdstyle="width: 100px">Employee Id :</td>|
<tdstyle="width: 100px"><asp:LabelID="Label1"runat="server"Text='<%# Eval("RowID") %>'></asp:Label></td>
</tr>

<tr>
<tdstyle="width: 100px">First Name:</td>
<tdstyle="width: 100px"><asp:LabelID="Label2"runat="server"Text='<%# Eval("FirstName") %>'></asp:Label></td>
</tr>

<tr>
<tdstyle="width: 100px">Last Name:</td>
<tdstyle="width: 100px"><asp:LabelID="Label6"runat="server"Text='<%# Eval("LastName") %>'></asp:Label></td>
</tr>

<tr>
<tdstyle="width: 100px">Title:</td>
<tdstyle="width: 100px"><asp:LabelID="Label3"runat="server"Text='<%# Eval("Title") %>'></asp:Label></td>
</tr>

<tr>
<tdstyle="width: 100px">Phone #:</td>
<tdstyle="width: 100px"><asp:LabelID="Label4"runat="server"Text='<%# Eval("PhoneNumber") %>'></asp:Label></td>
</tr>

<tr>
<tdstyle="width: 100px">Notes</td>
<tdstyle="width: 100px"><asp:LabelID="Label5"runat="server"Height="85px"Text='<%# Eval("Notes") %>'Width="216px"></asp:Label></td>
</tr>

</table>

//These values change based on the template (Update CommandName="Update" ) or (Insert CommandName="Insert")
<asp:LinkButtonID="editButton"runat="server"CommandName="Edit">Edit</asp:LinkButton>|<asp:LinkButtonID="createButton"runat="server"CommandName="New">Create New</asp:LinkButton><br/>

<br/>

</ItemTemplate>

Code behind:

1public partialclass _Default : System.Web.UI.Page2{3//global variables45int myRowID;678protected void Page_Load(object sender, EventArgs e)9 {10//COMING IN FRESH START AT 1 ELSE USE WHATEVER VALUE myRowID is passed1112if (myRowID ==0)13 {14 myRowID = 1001;15 }1617if (!Page.IsPostBack)18 {19 BindData();20 }2122 }2324//BIND DATA25protected void BindData()26 {27//Create Connection28string strConnectionString = ConfigurationManager.ConnectionStrings["pubsConnectionString"].ConnectionString;29 SqlConnection myConnection =new SqlConnection(strConnectionString);3031//Create the Command32string strCommandText ="SELECT * FROM [Fishbowl] WHERE ([RowID] = '"+myRowID+"')";33 SqlCommand myCommand =new SqlCommand(strCommandText, myConnection);3435//open the connection36 myConnection.Open();3738 FormView1.DataSource = myCommand.ExecuteReader();39 FormView1.DataBind();4041//Close Connection42 myConnection.Close();4344 }454647CREATE A NEW KEY/ROWID48public int getLastID()49 {50//Create Connection51string strConnectionString = ConfigurationManager.ConnectionStrings["pubsConnectionString"].ConnectionString;52 SqlConnection myConnection =new SqlConnection(strConnectionString);5354//Create the Command55string strCommandText ="SELECT max(RowID) FROM [Fishbowl] ";56 SqlCommand myCommand =new SqlCommand(strCommandText, myConnection);5758//open the database connection59 myConnection.Open();6061//convert the value into something we can use62int lastID = (int)myCommand.ExecuteScalar()+1;6364//close the connection65 myConnection.Close();66return lastID;67 }686970//SWITCH THE FORMVIEW MODES71protected void FormView1_ModeChanging(object sender, FormViewModeEventArgs e)72 {73switch (e.NewMode)74 {75case FormViewMode.Edit:76 FormView1.ChangeMode(FormViewMode.Edit);77break;78case FormViewMode.Insert:79 FormView1.ChangeMode(FormViewMode.Insert);80break;81default:82 FormView1.ChangeMode(FormViewMode.ReadOnly);83break;84 }85 BindData();86 }8788//UPDATE THE CONTENT89protected void FormView1_ItemUpdating(object sender, FormViewUpdateEventArgs e)90 {91//Create Connection92string strConnectionString = ConfigurationManager.ConnectionStrings["pubsConnectionString"].ConnectionString;93 SqlConnection myConnection =new SqlConnection(strConnectionString);9495try96 {97//Query to execute98string strQuery ="UPDATE [Fishbowl] SET [FirstName] = @dotnet.itags.org.FirstName, [LastName] = @dotnet.itags.org.LastName, [Title] = @dotnet.itags.org.Title, [PhoneNumber] = @dotnet.itags.org.PhoneNumber, [Notes] = @dotnet.itags.org.Notes WHERE [RowID] = @dotnet.itags.org.RowID";99100//Create the Command101 SqlCommand myCommand =new SqlCommand(strQuery, myConnection);102103// FormViewRow row = FormView1.Row;104 //Set up parameters105 TextBox txtFirstName = (TextBox)FormView1.FindControl("txtFirstName");106 TextBox txtLastName = (TextBox)FormView1.FindControl("txtLastName");107 TextBox txtTitle = (TextBox)FormView1.FindControl("txtTitle");108 TextBox txtPhoneNumber = (TextBox)FormView1.FindControl("txtPhoneNumber");109 TextBox txtNotes = (TextBox)FormView1.FindControl("txtNotes");110111 myCommand.Parameters.AddWithValue("@dotnet.itags.org.FirstName", txtFirstName.Text );112 myCommand.Parameters.AddWithValue("@dotnet.itags.org.LastName", txtLastName.Text);113 myCommand.Parameters.AddWithValue("@dotnet.itags.org.Title", txtTitle.Text);114 myCommand.Parameters.AddWithValue("@dotnet.itags.org.PhoneNumber", txtPhoneNumber.Text);115 myCommand.Parameters.AddWithValue("@dotnet.itags.org.Notes", txtNotes.Text);116 myCommand.Parameters.AddWithValue("@dotnet.itags.org.RowID", myRowID);117118//open the database connection119 myConnection.Open();120 myCommand.ExecuteNonQuery();121122 }123catch (Exception ex)124 {125//Houston We have problems126127 lblError.Text = ex.Message;128 }129finally130 {131//close the database connection132 myConnection.Close();133 }134135 FormView1.ChangeMode(FormViewMode.ReadOnly);136 BindData();137 }138139//i guess if we can get this work, then we can validate the updated row140141void FormView1_ItemUpdated(object sender, FormViewUpdatedEventArgs e)142 {143// for some strange reason this won't fire.. really don't know why144 }145146//Insert ROW147148149protected void FormView1_ItemInserting(object sender, FormViewInsertEventArgs e)150 {151152//Create Connection153string strConnectionString = ConfigurationManager.ConnectionStrings["pubsConnectionString"].ConnectionString;154 SqlConnection myConnection =new SqlConnection(strConnectionString);155156try157 {158//Query to execute159string strQuery ="INSERT [Fishbowl] ([FirstName], [LastName], [Title], [PhoneNumber] , [Notes], [RowID]) VALUES ( @dotnet.itags.org.FirstName, @dotnet.itags.org.LastName,@dotnet.itags.org.Title, @dotnet.itags.org.PhoneNumber, @dotnet.itags.org.Notes, @dotnet.itags.org.RowID)";160161//Create the Command162 SqlCommand myCommand =new SqlCommand(strQuery, myConnection);163164//Set up parameters165 TextBox txtFirstName = (TextBox)FormView1.FindControl("txtFirstName");166 TextBox txtLastName = (TextBox)FormView1.FindControl("txtLastName");167 TextBox txtTitle = (TextBox)FormView1.FindControl("txtTitle");168 TextBox txtPhoneNumber = (TextBox)FormView1.FindControl("txtPhoneNumber");169 TextBox txtNotes = (TextBox)FormView1.FindControl("txtNotes");170171 myCommand.Parameters.AddWithValue("@dotnet.itags.org.FirstName", txtFirstName.Text);172 myCommand.Parameters.AddWithValue("@dotnet.itags.org.LastName", txtLastName.Text);173 myCommand.Parameters.AddWithValue("@dotnet.itags.org.Title", txtTitle.Text);174 myCommand.Parameters.AddWithValue("@dotnet.itags.org.PhoneNumber", txtPhoneNumber.Text);175 myCommand.Parameters.AddWithValue("@dotnet.itags.org.Notes", txtNotes.Text);176 myCommand.Parameters.AddWithValue("@dotnet.itags.org.RowID", getLastID());177178//open the database connection179 myConnection.Open();180 myCommand.ExecuteNonQuery();181182 }183catch (Exception ex)184 {185//Houston We have problems186 lblError.Text = ex.Message;187 }188finally189 {190//close the database connection191 myConnection.Close();192 }193194 FormView1.ChangeMode(FormViewMode.ReadOnly);195 myRowID = getLastID() - 1;196 BindData();197 lblError.Text ="Row Added";198 }199}200201

any help suggestions will be greatly appriecated thx in adv

well maybe this is a way to do it... so I'll go with this way until something breaks

another way is just to hi-jack the sqlDataSource Commands in the code behind..

if (condition 1) {

SqlDataSource1.SelectCommand ="SELECT * FROM [Fishbowl] WHERE ([RowID] = '"+myRowID+"')";

}else{

//condition2

SqlDataSource1.SelectCommand ="SELECT * FROM [Fishbowl] WHERE ([RowID] = '"+myRowID+"')";

}

Duh!!!!

This way i'll total control over what i want to query :)

How to correct 'error - input string not in correct format'

Can anyone help me correct this.

This line is giving an error

Code Snippet

dblAmount[2] = double .Parse (BD.dbCommands.ExecuteScalar("SELECT SUM([AR-PAYMENT AMOUNT]) " + strSql, BD.MyGlobal._ARConnection).ToString());

error = Input string not in correct format.

Code Snippet

public static object ExecuteScalar(string queryStr, OleDbConnection connStr)

{

if (connStr.State != ConnectionState.Open)

{

connStr.Open();

}

OleDbCommand comm = new OleDbCommand(queryStr, connStr);

object returnObject;

returnObject = comm.ExecuteScalar();

return returnObject;

}

You are attempting to convert the result of executing ExecuteScalar to a double. If the result is not in a format supported by double then you'll get an error. Try storing the results in a string first to verify the results are what you expected. If no resultset is returned then you'll get a null which will fail.

In general you should avoid combining so much code into one line. It doesn't help performance at all, makes debugging harder and is harder to read. Separate out function calls to make it easier for you.

Michael Taylor - 5/30/07

http://p3net.mvps.org

Thanks for the help - could you explain this further for me

"In general you should avoid combining so much code into one line. It doesn't help performance at all, makes debugging harder and is harder to read. Separate out function calls to make it easier for you."

There really isn't a lot to explain. Where does the problem lie in your code? You aren't sure because the following line is doing several different things.

Code Snippet

dblAmount[2] = double .Parse (BD.dbCommands.ExecuteScalar("SELECT SUM([AR-PAYMENT AMOUNT]) " + strSql, BD.MyGlobal._ARConnection).ToString());

It could lie in the call to Parse, ExecuteScalar, perhaps the strSql or _ARConnection variables or even the assignment to the array. Many different places where things can go wrong. Additionally a cursory glance makes it difficult to tell what exactly is being passed to Parse as a parameter. There are several sets of parenthesis.

You are having a hard time figuring out what is going wrong because this is one busy line. By breaking it up you can more easily figure out where the problem lies. Even better is the fact that you can single step through the debugger and confirm each line executes the way you want. By using the debugger you'll be able to quickly identify whether the result of ExecuteScalar is bad, the result from Parse is bad, whatever. Now imagine that you come back to this code 6 months later. Or worse yet someone else has to manage this code. It is a lot of extra work.

Many "old" C programmers would write code like this believing that the less source lines you have the smaller and faster the code would run. This simply is not true. The compiler will generate fast and optimal code whether you put code on one line or several lines. Therefore you should strive for readability of code over writing the smallest number of lines. There are places where it makes sense to consolidate lines but not here. Here is how I'd write the code if I were doing it:

Code Snippet

object result = BD.dbCommands.ExecuteScalar("SELECT SUM([AR-PAYMENT AMOUNT]) " + strSql, BD.MyGlobal._ARConnection);

string strResult = (result != null) ? result.ToString() : "0";

dblAmount[2] = double.Parse(strResult);

Now the above code is probably broken out more than I would normally do. I generally recommend that function calls reside on a line by themselves. Use variables to store the results. You can consolidate a method call to a variable (like .ToString()) in an assignment for simplicity. The important point is "where would I need to step through if something goes wrong". Functions are at the top of the list so break lines that way. Of course over time you'll find your own technique that works well for you but the above may help to get you started.

Michael Taylor - 5/30/07

http://p3net.mvps.org

Thanks very much for your advice, I am an 'old' VB programmer who is just getting into c# so everything helps.

I would also suggest preferring TryParse instead of Parse.