I have a counter that onclick should increment 1 and it does that on click, but if I click the button again, it won't increment again. Instead it will be stuck at 1. How can I make it go up if the button is clicked more than once?
protected void submitAnswerButton_Click(object sender, EventArgs e)
{
int counter = 0;
if (mathAnswerTextBox.Text == answer.ToString())
{
answerStatus.Text = "Correct!";
}
else if (mathAnswerTextBox.Text != answer.ToString())
{
answerStatus.Text = "Incorrect";
counter++;
if (counter == 1)
{
incorrectStrikes.Text = counter.ToString();
}
else if (counter == 2)
{
incorrectStrikes.Text = counter.ToString();
}
else if (counter == 3)
{
incorrectStrikes.Text = counter.ToString();
}
}
You would need to make counter outside of the method, such as a field in the class, not a local variable:
private int counter = 0;
protected void submitAnswerButton_Click(object sender, EventArgs e)
{
if (mathAnswerTextBox.Text == answer.ToString())
{
answerStatus.Text = "Correct!";
...
Since this is a web application you'd probably want to store the counter in the session, something like:
Inside Page_Load:
if(!IsPostback)
{
Session["AttemptCount"] = 0
}
And then inside
protected void submitAnswerButton_Click(object sender, EventArgs e)
{
int counter = (int)Session["AttemptCount"];
if (mathAnswerTextBox.Text == answer.ToString())
{
answerStatus.Text = "Correct!";
...
//Make sure you include this on all paths through this method that
//affect counter
Session["AttemptCount"] = counter;
As it stands you counter is a local variable (as in below code) and so every time you click button it will get initialized to 0 and hence you get 1 every time cause it's getting incremented once.
protected void submitAnswerButton_Click(object sender, EventArgs e)
{
int counter = 0;
You'll need to store the value in a more global context, eg ViewState or Session or maybe even a HiddenField for storage of the value.
Conclusio: Web is stateless so you'd need a state-manager.
protected void submitAnswerButton_Click(object sender, EventArgs e)
{
var counter = this.ViewState["foo"] as int; // read it from the ViewState from the previous request, or set it to default(int) = 0 with as
// ... do your routine
this.ViewState["foo] = counter; // write it back to store it for the next request
}
Anyway - this is just valid in a web-context where you are stateless.
If you were in a webform/wpf-context you would rather go for a simple static, or instance-variable, or ... (whatever suits your current need, architecture, ...)
Related
I'm working with a Winforms app and I'm tyring to make a label "glide" up when a user clicks on it. To do this, I've created a click event that starts a timer, which then gradually moves the label up the form. I then have a counter that I increment, and when the counter reaches a certain position, the timer should stop. The timer is not stopping, however. I've deliberately set the counter limit to 2 for testing purposes, but the label continues to fly off the form. Here is the code:
private void DrawerTimer_Tick(object sender, EventArgs e)
{
int counter = 0;
newsLabel.Top -= 10;
counter++;
if (counter == 2)
drawerTimer.Stop();
}
private void News_Click(object sender, EventArgs e)
{
drawerTimer.Start();
}
int counter = 0; // here you are setting it 0
newsLabel.Top -= 10;
counter++; // here you are incrementing it by 1
if (counter == 2) // here you are checking for 2, its never going to get there
drawerTimer.Stop();
More than likely you will want to do something like this
private int _counter; // instance field, field to remember your count
private void DrawerTimer_Tick(object sender, EventArgs e)
{
newsLabel.Top -= 10;
counter++; // increment it every tick
if (counter == 2)
drawerTimer.Stop();
}
private void News_Click(object sender, EventArgs e)
{
_counter = 0; // set to zero when start
drawerTimer.Start();
}
I want to increase values on timer tick event but it is not increasing don't know what I am forgetting it is showing only 1.
<asp:Timer ID="Timer1" runat="server" OnTick="Timer1_Tick" Interval="1000"></asp:Timer>
private int i = 0;
protected void Timer1_Tick(object sender, EventArgs e)
{
i++;
Label3.Text = i.ToString();
}
You can use ViewState to store and then read the value of i again.
int i = 0;
protected void Timer1_Tick(object sender, EventArgs e)
{
//check if the viewstate with the value exists
if (ViewState["timerValue"] != null)
{
//cast the viewstate back to an int
i = (int)ViewState["timerValue"];
}
i++;
Label3.Text = i.ToString();
//store the value in the viewstate
ViewState["timerValue"] = i;
}
Check whether the form is posted back and then assign values. Check IsPostBack
private int i;
protected void Timer1_Tick(object sender, EventArgs e)
{
if (!IsPostBack)
{
i = 0;
}
else
{
i = Int32.Parse(Label3.Text);
i++;
}
Label3.Text = i.ToString();
}
Generally speaking it is not a good practice to store values inside of views (such as asp.net page). It could be overwritten each time the request is sent.
You could store your data elsewhere:
public static class StaticDataStorage
{
public static int Counter = 0;
}
And use it:
protected void Timer1_Tick(object sender, EventArgs e)
{
StaticDataStorage.Counter++;
Label3.Text = StaticDataStorage.Counter.ToString();
}
I want to increase an int variable i whenever I click on a button. But what I get is only int value of 1 and it doesn't increase anymore.
Here is my code:
private int i;
protected void btnStart_Click(object sender, EventArgs e)
{
i++;
lblStart.Text = i.ToString();
}
By each request (Clicking on the button), a new instance will be created.
So your non-static variable will be reset to 0.
You can define i as static:
private static int i;
protected void btnStart_Click(object sender, EventArgs e)
{
i++;
lblStart.Text = i.ToString();
}
But please note that the i variable is shared between all the users.
To improve this issue, you can use Session.
Session is an ability to store data of each user in a session.
So you can use following property to change the i variable in each session:
private int i
{
get
{
if (Session["i"] == null)
return 0;
return (int)Session["i"];
// Instead of 3 lines in the above, you can use this one too as a short form.
// return (int?) Session["i"] ?? 0;
}
set
{
Session["i"] = value;
}
}
protected void btnStart_Click(object sender, EventArgs e)
{
i++;
lblStart.Text = i.ToString();
}
As you know other answer is correct i want add another answer
You must in webform save your variables in ViewState
Just define your variables like this
public int i
{
get { Convert.ToInt32( ViewState["i"] ); }
set { ViewState["i"] = value ; }
}
Convert lblStart.Text value to int every time and assign it to i. Then increase i.
private int i;
protected void btnStart_Click(object sender, EventArgs e)
{
i = Int32.Parse(lblStart.Text);
i++;
lblStart.Text = i.ToString();
}
I have similar questions as yours and I believe the issue is because the event click did not store the value that has been increased before, therefore it could not be incremented the next time you clicked, so here's my code:
protected void btn_add_Click(object sender, EventArgs e)
{
string initial;
int increment;
int quantity;
initial = TextBoxQty.Text;
increment = Convert.ToInt16(initial);
increment++;
TextBoxQty.Text = increment.ToString();
quantity = increment;
}
You can use a hidden field, initialize them to 0.
private int i;
protected void btnStart_Click(object sender, EventArgs e)
{
i = int.Parse(myHiddenField.Value);
i++;
myHiddenField.Value = i;
lblStart.Text = i.ToString();
}
protected static int a = 0;
protected void btnStart_Click(object sender, EventArgs e)
{
a = a+1;
lblStart.Text = i.ToString();
}
It Works for me but on page_load() it initiates the value from 1 again !
this is actually my first time doing this
int i = 0;
while (i>=0)
{
Console.WriteLine(i);
Console.ReadLine();
i++;
}
Am new to C# and i need your help on this, I want to display one character at a time in a textbox this is my code
private void timer1_Tick(object sender, EventArgs e)
{
int i = 0; //why does this don't increment when it ticks again?
string str = "Herman Lukindo";
textBox1.Text += str[i];
i++;
}
private void button1_Click(object sender, EventArgs e)
{
if(timer1.Enabled == false )
{
timer1.Enabled = true;
button1.Text = "Stop";
}
else if(timer1 .Enabled == true )
{
timer1.Enabled = false;
button1.Text = "Start";
}
}
why does this don't increment when it ticks again?
Because your variable i is local to your event. You need to define it at class level.
int i = 0; //at class level
private void timer1_Tick(object sender, EventArgs e)
{
string str = "Herman Lukindo";
textBox1.Text += str[i];
i++;
}
On exit of your event, variable i becomes out of scope and looses its value. On the next event it is considered a new local variable with the initialized value of 0.
Next, you should also look for cross threaded exception. Since your TextBox is not getting updated on the UI thread.
The issue with you code is that you are assigning i = 0 with every tick, so it will always be 0 everytime it is used. I would suggest using a class level variable for this.
However, using a variable at class level means you are going to need to reset to 0 at some point, probably each time you start the timer.
A further point is that you are going to want to validate the tick event to ensure you don't try to access an index that doesn't exist (IndexOutOfRangeException). For this I would recommend automatically stopping the timer once the last letter has been printed.
With all that in mind, here is my suggested code:
int i = 0;// Create i at class level to ensure the value is maintain between tick events.
private void timer1_Tick(object sender, EventArgs e)
{
string str = "Herman Lukindo";
// Check to see if we have reached the end of the string. If so, then stop the timer.
if(i >= str.Length)
{
StopTimer();
}
else
{
textBox1.Text += str[i];
i++;
}
}
private void button1_Click(object sender, EventArgs e)
{
// If timer is running then stop it.
if(timer1.Enabled)
{
StopTimer();
}
// Otherwise (timer not running) start it.
else
{
StartTimer();
}
}
void StartTimer()
{
i = 0;// Reset counter to 0 ready for next time.
textBox1.Text = "";// Reset the text box ready for next time.
timer1.Enabled = true;
button1.Text = "Stop";
}
void StopTimer()
{
timer1.Enabled = false;
button1.Text = "Start";
}
This following code handle button click event. When the user click first time it sets the lable as "First Time", and when the user click second time it sets the lable as "Second Time". But it doesn't work properly. When I first click it, it sets the lable as "First time", which is correct, but when I click second time, nothing happend.
My code:
int counter=0;
protected void btnCompTagUpdate_Click(object sender, EventArgs e)
{
if (counter == 0)
{
lable1.Text="First Time";
counter++;
}
else if (counter == 1)
{
lable1.Text="Second Time";
counter--;
}
}
How can I fix it?
The values of instance fields like counter are not saved across postbacks. You need to store counter in ViewState, Session, or some other persistent store, whichever is more appropriate. For example:
private int Counter
{
get { return ((int?)this.ViewState["Counter"]).GetValueOrDefault(); }
set { this.ViewState["Counter"] = value; }
}
Then reference this.Counter instead of counter in btnCompTagUpdate_Click.
If "Coutner" is initialized exactly in the way you are listing, then that's your problem. Coutner gets re-initialized to zero after every postback. You need to save Coutner's state -- I normally recommend against it for any but the simplest cases, but I think you have a valid case for the use of ViewState.
void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
Session["counter"]=0;
}
You set the counter value at once, when first the page loads.
protected void btnCompTagUpdate_Click(object sender, EventArgs e)
{
int counter=0;
if (Session["counter"]!=null)
counter= Convert.ToInt32(Session["counter"]);
if (counter == 0)
{
lable1.Text="First Time";
counter++;
Session["counter"]=counter;
}
else if (counter == 1)
{
lable1.Text="Second Time";
counter--;
Session["counter"]=counter;
}
}
You only need to change the way you increase the counter in the method. You are not saving it back as a new variable after the button click.
int counter = 0;
protected void btnCompTagUpdate_Click(object sender, EventArgs e) {
if (counter == 0) {
counter = counter + 1;
label1.Text="First Time";
}
else if (counter == 1) {
counter = counter - 1;
label1.Text="Second Time";
}
}