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C# GUI application that stores an array and displays the highest and lowest numbers by clicking a button
This is updated from 13 hours ago as I have been researching and experimenting with this for a few. I'm new to this programming arena so I'll be short, I'm teaching myself C# and I'm trying to learn how to have integers from a user's input into a textbox get calculated from a button1_Click to appear on the form. Yes, this is a class assignment but I think I have a good handle on some of this but not all of it; that's why I'm turning to you guys. Thanks for all of the advice guys.
I'm using Microsoft Visual Studio 2010 in C# language. I'm using Windows Forms Application and I need to create a GUI that allows a user to enter in 10 integer values that will be stored in an array called from a button_Click object. These values will display the highest and lowest values that the user inputted. The only thing is that the array must be declared above the Click() method.
This is what I have come up with so far:
namespace SmallAndLargeGUI
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
public void inputText_TextChanged(object sender, EventArgs e)
{
this.Text = inputText.Text;
}
public void submitButton_Click(object sender, EventArgs e)
{
int userValue;
if(int.TryParse(inputText.Text, out userValue))
{
}
else
{
MessageBox.Show("Please enter a valid integer into the text box.");
}
int x;
x = Convert.x.ToString();
int squaredResults = squared(x);
int cubedResults = cubed(x); squared(x);
squaredLabel.Text = x.ToString() + " squared is " + squaredResults.ToString();
cubedLabel.Text = x.ToString() + " cubed is " + cubedResults.ToString();
}
public static int squared(int x)
{
x = x * x;
return x;
}
public static int cubed(int x)
{
x = x * squared(x);
return x;
}
}
}
Now I can't run this program because line 38 shows an error message of: 'System.Convert' does not contain a definition for 'x' Also I still have to have an array that holds 10 integers from a textbox and is declared above the Click() method. Please guys, any help for me? This was due yesterday.
As a couple of comments have mentioned, there really isn't enough information here to provide you with a useful answer. There are two main User Interface frameworks in .Net for windows applications. One of these is commonly referred to as "WinForms" and the other is "WPF" or "Windows Presentation Foundation."
I'm going to go with you are most likely using WinForms as it is the older of the two technologies. The approach here can be used on both sides with a little tweaking. Setting text in a text box is very similar to setting text programaticly on a label. You can get more detail on that on MSDN: How to: Display Text on a Windows Form; How to: Use TextBox Controls to Get User Input.
If you are using WPF the "back end" code is pretty much the same. You just need to make sure your textbox has an x:Name="userInputTextBox" so you can reference it in your code behind. Be mindful that your users can input "1", "3" or "abcd" in the field. Ensuring your app doesn't bomb is most likely outside of the assignment but feel free to look up C# int.TryParse(...) and "Try Catch" :-)
Your button handler could look like this:
void btnUserClick_Click(object sender, System.EventArgs e)
{
int userValue;
if(int.TryParse(txtUserInput.Text, out userValue))
{
// We have the value successfully, do calculation
}
else
{
// We don't have the users value.
MessageBox.Show("Please enter a valid integer into the text box.")
}
}
In your retrieveInput_Click handler you are assigning the min/max numbers to a local int. Once you determine your min/max numbers in the logic, you will need to assign those local integers to a UI element for display.
Since we don't have any details on your specific UI choices, one simple solution could be to add 2 labels to your form, and then in the code you would place the result in the label:
for (int i = 0; i < numbers.Length; ++i)
{
if (numbers[i] < min)
min = numbers[i];
if (numbers[i] > max)
max = numbers[i];
}
// Assign Minimum to Label1
Label1.Text = "Minimum Value: " + min.ToString();
// Assign Maximum to Label2
Label2.Text = "Maximum Value: " + max.ToString();
define the textbox named textbox1 or txt_name
you can write the button1_Click function :
int i_value = Convert.ToInt16(txt_name.Text);
ok. I haven't try catch the exceptions.... :(
maybe above answer is right.
btw, i think this question mainly focus on how to get int type from text box. right?
Related
Good day fellow helpers, i have following problem:
(running MS Visual Community Edition 2015)
private void button4_Click(object sender, EventArgs e) // Senden
{
serialPort2.WriteLine("SR,00,002\r\n");
textBox1.Text = "gesendet";
textBox3.Text = "";
try
{
System.IO.StreamReader file = new System.IO.StreamReader("C:\\blub.txt");
String line = file.ReadToEnd();
string Hallo = line; \\in the beginning there is "0" in the file
file.Close();
decimal counter = Convert.ToDecimal(Hallo); \\just for testing
counter++;
string b = serialPort2.ReadLine();
string[] b1 = Regex.Split(b, "SR,00,002,"); \\cuts off unwanted input from device
decimal b2 = decimal.Parse(b1[1]); \\number like -3000
System.IO.StreamWriter test = new System.IO.StreamWriter("C:\\blub.txt");
test.WriteLine(counter);
test.Close();
textBox7.Text = "Das ist counter:" + counter;
}
catch (TimeoutException)
{
textBox3.Text = "Timeout";
throw;
}
}
Now, the Serialport is a device that returns a lengthmeasurment. As it is a bit weird, or just the way its build it start with a negitve number (between -5000 and -3370). Now as i want to get measurement on the screen that is realistic i want to set the value to 0 and calculate the difference.
Means: I start the programm - press send - get a value (say -3000) - press send again (after pushing the seonsor in) and get the value that its been pushed in > 0 by adding the difference to 0.
I only learned to store values externally when i had a C course a year back like i did within my programm. Is there a way to store the value from the first measurement in the programm so i can use it on the next send/try?
The counter was just for testing and I would exchange it for the "decimal b2"
I hope there is an easy fix for that, not really a pro with C# yet but i'm eager to learn. I thank the willing helpers in advance, MfG, Chris
OK, I will simplify this in order to show concept so it will not have all the code you are actually using.
So, what you want is to click on button, get some values and store them for next click.
Value is stored in variable. If you have variable in function that is handler for click event, as soon as function completes execution, value will be destroyed.
So, what you need is to create variable in outer scope (class level). Your function is already in class of the form so let's get to code:
class Form1
{
string BetweenClickStorage;
private void button4_Click(object sender, EventArgs e)
{
//Load data here
BetweenClickStorage = LoadedData;
}
}
After this, when you click again on the button, value will still be in BetweenClickStorage. It will be also available to all other buttons click handlers and other code in that form.
If I'm understanding your question correctly, the answer is simply to declare a variable outside the try/catch:
//declare variable //
var measurement;
// TRY #1 //
try
{
//assign value to the variable here
}
catch
{
}
// TRY #2 //
try
{
// reference variable here
}
catch
{
}
Good evening all,
I've just started my second year at University and I'm learning C# for the first time. I've had some coding experience with Java and Javascript before but never c#.
I'm having problems with a basic credit/debit program. See code below:
private double balance = 0;
private string creditamount;
private string debitamount;
private double currentamount = 0;
private void CreditButton_Click(object sender, RoutedEventArgs e)
{
AmountField.Text = creditamount;
Convert.ToDouble(creditamount);
CurrentBalance.Text = "Your current balance is £" + (creditamount + balance);
}
private void DebitButton_Click(object sender, RoutedEventArgs e)
{
AmountField.Text = debitamount;
double.Parse(debitamount);
CurrentBalance.Text = "Your current balance is £" + (debitamount - balance);
}
The user should enter an amount into the AmountField and press either the Credit or Debit button. Upon clicking either button, the amount should be converted from a string into a double and then shown in the CurrrentBalance .Text
It apppears that my strings aren't being converted into doubles.
I've tried using Convert.ToDouble(); and double.Parse(); but Visual Studio keeps giving me errors.
Does anyone have any suggestions?
The = assignment goes from Right to Left. Also all Convert.ToStuff return the result, so you should be expecting it (assign it to some variable).
Therefore, your event handlers (and all your future routine) should look similar to this:
private void DebitButton_Click(object sender, RoutedEventArgs e)
{
debitamount= AmountField.Text ; // Take the Right and assign it to the Left
currentamount = Convert.ToDouble(debitamount); // convert + assign
CurrentBalance.Text = "Your current balance is £" + (debitamount - balance); // Again take the Right and assign it to the Left
}
First of all if you are using wpf try to avoid this code behind thing. Secondly try to take advantage of MVVM. What is MVVM. Go through this link.
http://www.codeproject.com/Articles/165368/WPF-MVVM-Quick-Start-Tutorial
So in short i would suggest create a Viewmodel class and make it implement INotifyPropertyChanged. Create your credit and debit amount properties bind it in the UI and don't forget to use OnPropertyChanged on these properties. So when ever user enters any text in the UI i.e when ever there is a change in the UI state your set block of the variables will be called and you can proceed further. Also in mvvm you use commands not button clicks. Also set the data context of you xaml to this view model.
I am creating a windows form that is a random number guessing game. I've made these before in C++ and never had an issue, however I have a big one here- I have no idea how to get the user back to input a number after the loop has began running. Here is my code:
private void btnGuess_Click(object sender, EventArgs e)
{
int guess = 0;
int count = 0;
int accumulator = 0; // accumulator
Random rand = new Random();
int number = rand.Next(1, 100);
txtAnswer.Focus();
while (guess != number)
{
guess = int.Parse(txtAnswer.Text);
if (guess < number)
{
MessageBox.Show("Too Low! Guess again!");
txtAnswer.Text = "";
txtAnswer.Focus();
count++;
accumulator++;
}
else if (guess > number)
{
MessageBox.Show("Too High! Try again!");
txtAnswer.Text = "";
txtAnswer.Focus();
count++;
accumulator++;
}
else
{
MessageBox.Show("Correct! you guessed the number in " + accumulator + " tries!");
break;
}
}
}
}
}
I just filled the while loop arguments with something for you guys, even though i know it won't work. Basically, I need to run the loop, get feedback (if the users guess was too high or low) then get the user to be able to input another number BEFORE the loop runs again. I don't know how to get that to happen with a text box control which is where the input will be. Any ideas?
You should not loop inside in the btnGuess_Click. Instead you need to store the state (the number, count, and the accumulator variables) in the scope of the form itself.
Initialize the random number when the form loads, or using some kind of start button.
Then inside the guess button handler, read the text box value and compare it to the number variable, such as what you are doing currently.
What you are building is more a console style application. So there is 1 main loop that is executing all the code.
In forms applications it is an event driven environment. So the user gets a form, presses a button, the form is evaluated and then the method handling ends.
So you have on a class level some variables for counts, in the constructor you add the initialization and the method for submit will be something like
private void btnGuess_Click(object sender, EventArgs e)
{
//Increment counters
//Check
//Show feedback
//Leave the button click code
}
For some more info, check this out:
https://msdn.microsoft.com/en-us/library/dd492132.aspx
I'm working on a programming assignment, and I'm trying to make this button take the values from two textboxes, and calculate the new location for the form window. I'm having trouble converting the textbox values to type int, and being made usable by the btnCompute_click method.
private void btnCompute_Click(object sender, EventArgs e)
{
int x = Convert.ToInt32(txtXvalue);
int y = Convert.ToInt32(txtYvalue);
Location = new Point(x,y);
}
private void xValue_TextChanged(object sender, EventArgs e)
{
int xValue =
Convert.ToInt32(txtXvalue);
}
private void yValue_TextChanged(object sender, EventArgs e)
{
int y =
Convert.ToInt32(txtYvalue);
}
I forgot to add some additional info, the acceptable values for x and y must be positive. Would I use an if...else statement to control the acceptable values?
user29... i have no idea why death... replied that. it makes no sense to me. but you question makes sense to me. i suppose death... did not understand your question.
First off, everything you ask does not need anything in the TextChanged methods.
Do all your handling in the btnCompute_Click() method because you want to do something *when you click your button, not when the user edits the text of the text boxes, according to your question.
The code that is in your TextChanged() methods will get executed whenever the Text values of those text boxes change. that's not what you asked for it to do. But you could use these events for example, if you wanted a label to become visible or hidden and to set the text of a label which shows text, so you can use it as an error message label, for instance if the integer value of a text box is negative or even if it cannot be parsed.
So in your btnCompute_Click() methods, you first want to get the int values. You need to decide exactly what you want your code to do if the text is not integers. In my opinion, most beginners code things like message boxes or something. I like to give the user feedback with Labels or a status bar message, depending on what I feel is appropriate. Since my first choice would be to use a Label to show the 'error' message when text boxes cannot be parsed to integers, then i would simply return from the button click method without doing anything when the values are not what i want. That way the user gets their messages without annoying popup message boxes or anything. But it's up to you whether you want to pop up a message box or not. Others have given you good code to do that. I want to give you good code that avoids what i consider annoying popup boxes.
When converting strings to an int, Convert.ToInt32 will throw an error if the string cannot be parsed. int.TryParse is the silver bullet for truly parsing strings to integers without any error. Here is the entire code i would use. I made a new project just to make sure i'm not giving you buggy code. I give you my code on how I handle this.
In your updated prerequisite, you mention x & y must be positive and not negative. I note to you that these are not the same. For instance, 0 is neither positive nor negative. I assume that you technically mean that x and y cannot be negative, (and that it does not need to be positive, since 0 should be allowed).
private void Form1_Load(object sender, EventArgs e)
{
lblErrorX.Text = null;
lblErrorY.Text = null;
}
private void btnMoveForm_Click(object sender, EventArgs e)
{
int x = 0; if (int.TryParse(txtX.Text, out x) == false) { return; }
int y = 0; if (int.TryParse(txtY.Text, out y) == false) { return; }
if (x < 0 || y < 0) { return; }
this.Location = new Point(x, y);
}
private void txtX_TextChanged(object sender, EventArgs e)
{
int x = 0;
if (int.TryParse(txtX.Text, out x) == false)
{ lblErrorX.Text = "X is not an valid integer."; return; }
if (x < 0) { lblErrorX.Text = "X cannot be negative."; return; }
lblErrorX.Text = null;
}
private void txtY_TextChanged(object sender, EventArgs e)
{
int y = 0;
if (int.TryParse(txtY.Text, out y) == false)
{ lblErrorY.Text = "Y is not an valid integer."; return; }
if (y < 0) { lblErrorY.Text = "Y cannot be negative."; return; }
lblErrorY.Text = null;
}
In my project, on the form, in the following left to right order: lblX, txtX, lblErrorX. I have the same corresponding for Y: lblY, txtY, lblErrorY. Then i have one Button: btnMoveForm. So my txtX corresponds to your txtXvalue. my btnMoveForm corresponds to your btnCompute, but to me, 'compute' means to calculate, which is not really what this button is doing. this button is moving the form, so that's why i name it as such.
I have played with setting both the Location and the DesktopLocation and it seems to do the same thing. I've always used Location and i just learned that DesktopLocation works too, but since Location is shorter, i use it.
Someone asked why i don't use if(!int.TryParse(...)) { return; } rather than my if(int.TryParse(...) == false) { return; }. My reason is unfortunately that i think ! is an easy one character to miss when reading code, so i avoid it, especially when that little mistake means the opposite of what the code really would do. So my use of '== false' is always for human clarity. But i do like the C# ease of only needing one character. I just think it's a shame that in my opinion, it's a lot safer to write code that is better for humans so we don't mistake it. That's the only reason i use '== false' instead of !. Use ! if you like. It's quite convenient. I regret not using it. hehe.
Oh, and the reason i set the lblErrorX.Text = null; and lblErrorY.Text = null; is on my form in design view, i give them a text value so i can see them. :) so when the program runs, i set the Text to be blank. But you can use the Visible property if you prefer. I just leave them always visible and only set their Text properties.
Based on your expanded criteria you can check for negative numbers conditionally or use Math.Abs to get the absolute value. Something like this.
int x, y;
if (int.TryParse(txtXvalue.Text, out x) && int.TryParse(txtYvalue.Text, out y))
{
if (x < 0 || y < 0)
{
MessageBox.Show("Negative numbers not allowed");
}
else
Location = new Point(x, y);
}
else
{
MessageBox.Show("Must be an Integer");
}
or
int x, y;
if (int.TryParse(txtXvalue.Text, out x) && int.TryParse(txtYvalue.Text, out y))
{
Location = new Point(Math.Abs(x), Math.Abs(y));
}
else
{
MessageBox.Show("Must be an Integer");
}
I think you are looking for this.
private void btnCompute_Click(object sender, EventArgs e)
{
int x = Convert.ToInt32(txtXvalue.Text);
int y = Convert.ToInt32(txtYvalue.Text);
DesktopLocation = new Point(Math.Abs(x), Math.Abs(y));
}
This gets the location for the desktop. Also you need the .Text to get the text inside the textbox. You should also check to make sure the text is not null or empty before using or it will cause an error.
If this isn't what you are looking for please explain a little more.
I need to add a textbox in my application that starts showing with the value 0.00 just like a ATM, as you type the numbers then it keeps the two decimal point until satisfied with the value for example the sequence to end up of a value of 1023.00 would be (as I type)
0.01
0.10
1.02
10.23
102.30
1023.00
Is this possible to do in a windows forms application?. I am just not sure how to go about it.
Thank you.
In this kind of scenario I would not use a textbox, but a label or a read-only textbox. To get the user input just use the key-press event on your form (you have to enable KeyPreview on the form too) - then just remember the keys/numbers pressed and output the format you are targeting - should be a rather easy algorithm (Char.IsNumber, and String.Format might come in handy):
private int _inputNumber = 0;
private void Form_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)
{
if (!Char.IsNumber(e.KeyChar)) return;
_inputNumber = 10*_inputNumber + Int32.Parse(e.KeyChar.ToString());
ReformatOutput();
}
private void ReformatOutput()
{
myOutput.Text = String.Format("{0:0.00}", (double)_inputNumber / 100.0);
}
Note: Why not use a textbox - because it's internal logic with select/replace/remove/type is so overcomplicated that the cases you would have to check are just to much to handle gracefully - so instead of trying to change a cannon into a sling you should start with the sling.