Trouble with my variable conversion

simon taylor

Hi,
i am trying to accumulate a total to be stored in my 'targetTotal' variable of type int which is then to be sent to my msaccess db into a field called 'targetTotal' of type LongInteger, the trouble i am having now is that after adding my totals given the following code snippet:
targetOneDay = Convert.ToInt32(nine_to_fourteenhrstxbx.Text);//tonine_to_fourteenhrstxbx.Text;
targetTwoDay = Convert.ToInt32(fifteen_to_fortfourglhtxtbx.Text);
targetFiveDay = Convert.ToInt32(fourtyfive_to_74txtbx.Text);
targetTenDay = Convert.ToInt32(min75glhtxtbx.Text);
targetTotal = Convert.ToInt32(totaltargettxtbx.Text);
targetTotal = targetOneDay + targetTwoDay + targetFiveDay + targetTenDay;
i get an error which says the following: 'Input string was not in correct format' pointing to the target total variable. So i looked online for this particular error and based on my understanding i have to check if it is a null value and convert it accordingly. So what i first did was created another variable called 'total' of type int, removed the 'text' property of my target total and added the following if statement:
targetTotal = Convert.ToInt32(totaltargettxtbx);
if (targetTotal != null)
total = Convert.ToInt32(targetTotal);
else
total = 0;

now when i run my applicantion i get another error saying: Unable to cast object of type 'System.Windows.Forms.TextBox' to type 'System.IConvertible'. which is pointing to my targetTotal variable.
Can somebody kindly assist me with my issue please.

17 Replies

Know the answer? Post it — somebody with the same question will find it here.

Sam Hobbs15y ago
The forum owners and moderators ask me to ask you to check the checkbox that says do you like this answer (whatever it says) for the message that answers your question. For one reason, it helps people in the future. For another reason, it gives credit to the person that helped the most. Note that the checkbox can be checked for only one post per thread.
simon taylor15y ago
Everybody, thanks for your help, Sam, thanks for sticking with my thread, definetly a lessoned to be learned here, much apprecaited. Again thanks :)

Sam Hobbs15y ago

I think the following is closer to what you need.

string projectName;

string startDate;

string endDate;

int targetOneDay = 0;

int targetTwoDay = 0;

int targetFiveDay = 0;

int targetTenDay = 0;

int targetTotal = 0;

int total = 0;

string dbinsert;



projectName = nametxtbx.Text;



startDate = startdatetimepcker.Value.ToString();

endDate = enddatetimepcker.Value.ToString();



if (!Int32.TryParse(nine_to_fourteenhrstxbx.Text, out targetOneDay))

	MessageBox.Show("nine_to_fourteenhrstxbx has incorrect data");

if (!Int32.TryParse(fifteen_to_fortfourglhtxtbx.Text, out targetTwoDay))

	MessageBox.Show("fifteen_to_fortfourglhtxtbx has incorrect data");

if (!Int32.TryParse(fourtyfive_to_74txtbx.Text, out targetFiveDay))

	MessageBox.Show("fourtyfive_to_74txtbx has incorrect data");

if (!Int32.TryParse(min75glhtxtbx.Text, out targetTenDay))

	MessageBox.Show("min75glhtxtbx has incorrect data");



targetTotal += targetOneDay + targetTwoDay + targetFiveDay + targetTenDay;



total = targetTotal;



if (!Int32.TryParse(totaltargettxtbx.Text, out targetTotal))

	MessageBox.Show("totaltargettxtbx has incorrect data");



OleDbConnection con = new OleDbConnection();

//dbinsert = "INSERT into Project(projectName, startDate, endDate, duration, targetOne, targetTwo, targetFive, targetTen, targetTotal)" +

//"VALUES" + "(" + "'" + projectName + "'" + "," + "'" + startDate + "'" + "," + "'" + endDate + "'" + "," + "5" + "," + targetOneDay + "," + targetTwoDay + "," + targetFiveDay + "," + targetTenDay + "," + total + ")";

string dbinsertFormat = "INSERT into Project(projectName, startDate, endDate, duration, targetOne, targetTwo, targetFive, targetTen, targetTotal)" +

	"VALUES('{0}','{1}','{2}',5,{3},{4},{5},{6},{7})";

dbinsert = string.Format(dbinsertFormat, projectName, startDate, endDate, targetOneDay, targetTwoDay, targetFiveDay, targetTenDay, total);

OleDbCommand cmd = new OleDbCommand(dbinsert, con);

cmd.ExecuteNonQuery();

cmd.Dispose();

con.Close();

Note that I also reorganized the way you generate the insert command. It is a recommendation; you don't have to do it that way, but I think it makes things easier. If you do it my way, then you can put the dbinsertFormat string someplace else where it is out of the way. Note that you probably need to also change the way the dates are specified, but I am not sure of the details; others can help you more with that than I can. Also, it is possible ot create a command using parameters; I think that shold be the next thing for you to learn.

Suthish Nair15y ago

projectName = Convert.ToString(nametxtbx.Text);
  
startDate = startdatetimepcker.Value.ToString(); 
endDate = enddatetimepcker.Value.ToString();

targetOneDay = (nine_to_fourteenhrstxbx.Text.ToString().Trim() == "" ? 0 : Convert.ToInt32(nine_to_fourteenhrstxbx.Text));
targetTwoDay = (fifteen_to_fortfourglhtxtbx.Text.ToString().Trim() == "" ? 0 : Convert.ToInt32(fifteen_to_fortfourglhtxtbx.Text));
targetFiveDay = (fourtyfive_to_74txtbx.Text.ToString().Trim() == "" ? 0 : Convert.ToInt32(fourtyfive_to_74txtbx.Text));
targetTenDay = (min75glhtxtbx.Text.ToString().Trim() == "" ? 0 : Convert.ToInt32(min75glhtxtbx.Text));

targetTotal = targetOneDay + targetTwoDay + targetFiveDay + targetTenDay;
totaltargettxtbx.Text = (totaltargettxtbx.Text.ToString().Trim() == "" ? 0 : Convert.ToInt32(totaltargettxtbx.Text));

if (totaltargettxtbx.Text != null) 
 total = targetTotal; 
 targetTotal = Convert.ToInt32(totaltargettxtbx.Text); 
else 
 total = 0;  
  
cmd = null;

simon taylor15y ago
Here is my full code as it stands which i think i should have done:

private void submitbtn_Click(object sender, EventArgs e)
{
string projectName;
string startDate;
string endDate;
int targetOneDay =0;
int targetTwoDay = 0;
int targetFiveDay = 0;
int targetTenDay = 0;
int targetTotal =0;
int total = 0;
string dbinsert;

projectName = Convert.ToString(nametxtbx.Text);//nametxtbx.Text;

startDate = startdatetimepcker.Value.ToString();
endDate = enddatetimepcker.Value.ToString();
targetOneDay = Convert.ToInt32(nine_to_fourteenhrstxbx.Text);
targetTwoDay = Convert.ToInt32(fifteen_to_fortfourglhtxtbx.Text);
targetFiveDay = Convert.ToInt32(fourtyfive_to_74txtbx.Text);
targetTenDay = Convert.ToInt32(min75glhtxtbx.Text);

targetTotal += targetOneDay + targetTwoDay + targetFiveDay + targetTenDay;

if (totaltargettxtbx.Text != null)
total = targetTotal;
else
total = 0;

targetTotal = Convert.ToInt32(totaltargettxtbx.Text);

cmd = null;

dbinsert = "INSERT into Project(projectName, startDate, endDate, duration, targetOne, targetTwo, targetFive, targetTen, targetTotal)" +
"VALUES" + "("+"'"+projectName+"'"+"," + "'" + startDate+"'"+","+"'"+endDate+"'"+","+"5"+","+targetOneDay+"," + targetTwoDay+","+targetFiveDay+","+targetTenDay+","+total+ ")";
cmd = new OleDbCommand(dbinsert, con);
cmd.ExecuteNonQuery();
cmd.Dispose();
con.Close();

}
although i'm still getting the same issue
simon taylor15y ago
ok yes, i'm listening very tentatively
Sam Hobbs15y ago
Okay well see targetTotal is already an "int" so it does not need to be converted, right?
simon taylor15y ago
hi, apologise for not showing my initial declarations, i'm still pretty new to this so here it is:
private void submitbtn_Click(object sender, EventArgs e)
{
string projectName;
string startDate;
string endDate;
int targetOneDay =0;
int targetTwoDay = 0;
int targetFiveDay = 0;
int targetTenDay = 0;
int targetTotal =0;
int total = 0;
i also want to point out that before i added the targetTotal thing, i was able to send the resulst of all my other targetXXDay's to my ms access database since adding the targetTotal stuff it all went down hill. Hope that helps.
Sam Hobbs15y ago
Okay so targetTotal is of type Long Integer in your Access database, but what is it declared to be in your C# code? There is no such thing as Long Integer in C# so that is not relevant to your C# code. What is it in C#? It helps to show the declarations of variables such as that in the code you post; it can save a lot of time.
simon taylor15y ago
Suthish Nair
i did actaully try your code BUT there was an error message of :Input string was not in a correct format. pionting to this line: targetTotal = (nine_to_fourteenhrstxbx.Text.ToString().Trim() == "" ? 0 : Convert.ToInt32(totaltargettxtbx.Text));
simon taylor15y ago
i am doing,
total = Convert.ToInt32(targetTotal);

because in my ms access db the field name targetTotal is of type Long Integer, and i believe i would need to convert it to a 32-bit value inorder to send it to my db. Yes, targetTotal targetTotal as it's of type int.
Suthish Nair15y ago
Simon
did you tried the code i posted.
Sam Hobbs15y ago
What line are you getting the error message from? I assume the line that calls Convert.ToInt32(totaltargettxtbx.Text). You need to check totaltargettxtbx.Text for null before that!

Why are you doing:
total = Convert.ToInt32(targetTotal);
That does not make sense to me, since targetTotal is not a string; correct?
simon taylor15y ago
Hi,
thanks for the reply guys, did mange to try out Subhendu De's answer which worked fine, BUT i when i used Sam Hobbs answer, this is what i did:

targetTotal = Convert.ToInt32(totaltargettxtbx.Text); // error pointing here

targetTotal += targetOneDay + targetTwoDay + targetFiveDay + targetTenDay;

if (totaltargettxtbx.Text != null)
total = Convert.ToInt32(targetTotal);
else
total = 0;

i get the following error message: Input string was not in a correct format. which pionts to the tartTotal variable line. Yes, it is a textbox, when i hover my mouse over the variables, i see the values but when hovering over the targetTotal variable it does not show the result. Although the other solution does work, I would still be greatful if you could still assist me with this Sam Hobbs beceause if i get this same issue 6 months down the line, i have more ammo in my arsenal as it were to deal with this type of problem.
Sam Hobbs15y ago
I think the following code is incorrect:
targetTotal = Convert.ToInt32(totaltargettxtbx);
if (targetTotal != null)
total = Convert.ToInt32(targetTotal);
else
total = 0;
I assume that totaltargettxtbx is a TextBox. If so then that is why you are getting the message "Unable to cast".... since totaltargettxtbx is not a string.

So you need to use totaltargettxtbx.Text. Also, it is totaltargettxtbx.Text that you need to check for null. It is irrelevant (not useful) to check targetTotal for null.

Suthish Nair15y ago

Another simple way :)

targetOneDay = (nine_to_fourteenhrstxbx.Text.ToString().Trim() == "" ? 0 : Convert.ToInt32(nine_to_fourteenhrstxbx.Text));
targetTwoDay = (nine_to_fourteenhrstxbx.Text.ToString().Trim() == "" ? 0 : Convert.ToInt32(fifteen_to_fortfourglhtxtbx.Text));
targetFiveDay = (nine_to_fourteenhrstxbx.Text.ToString().Trim() == "" ? 0 : Convert.ToInt32(fourtyfive_to_74txtbx.Text));
targetTenDay = (nine_to_fourteenhrstxbx.Text.ToString().Trim() == "" ? 0 : Convert.ToInt32(min75glhtxtbx.Text));
targetTotal = (nine_to_fourteenhrstxbx.Text.ToString().Trim() == "" ? 0 : Convert.ToInt32(totaltargettxtbx.Text));

Subhendu De15y ago
Try in this way

if(!nine_to_fourteenhrstxbx.Text.Trim().Equals(String.Empty))
    targetOneDay = Convert.ToInt32(nine_to_fourteenhrstxbx.Text);
else
    targetOneDay=0;
if(!fifteen_to_fortfourglhtxtbx.Text.Trim().Equals(String.Empty))
    targetTwoDay = Convert.ToInt32(fifteen_to_fortfourglhtxtbx.Text);
else
    targetTwoDay = 0;
if(!fourtyfive_to_74txtbx.Text.Trim().Equals(String.Empty))
    targetFiveDay = Convert.ToInt32(fourtyfive_to_74txtbx.Text);
else
    targetFiveDay = 0;
if(!min75glhtxtbx.Text.Trim().Equals(String.Empty))
    targetTenDay = Convert.ToInt32(min75glhtxtbx.Text);
else
    targetTenDay = 0;

if(!totaltargettxtbx.Text.Trim().Equals(String.Empty))
    targetTotal = Convert.ToInt32(totaltargettxtbx.Text);
else
    targetTotal = 0;

targetTotal = targetOneDay + targetTwoDay + targetFiveDay + targetTenDay;

Thanks.....