Closed. This question is not reproducible or was caused by typos. It is not currently accepting answers.
This question was caused by a typo or a problem that can no longer be reproduced. While similar questions may be on-topic here, this one was resolved in a way less likely to help future readers.
Closed 9 years ago.
Improve this question
I am trying to learn programming and I am starting with a book called Software Development Fundamentals. However I am having loads of difficulty understanding certain subjects. Especially because my native language is not English. I am stuck at the subject (events) and (delegates). I feel like this is to difficult for me, I can not even get this code to work!
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Lesson02
{
class Program
{
static void Main(string[] args)
{
Rectangle r = new Rectangle();
r.Changed += new EventHandler(r_Changed);
r.Length = 10;
}
static void r_changed(object sender, EventArgs e)
{
Rectangle r = (Rectangle)sender;
Console.WriteLine(
"Value Changed: Length = {0}",
r.Length);
}
}
class Rectangle
{
public EventHandler Changed;
private double length;
public double Length
{
get
{
return length;
}
set
{
length = value;
Changed(this, EventArgs.Empty);
}
}
}
}
I get this error:
Error 1 The name 'r_Changed' does not exist in the current context 14 59 Lesson02
C# is case-sensitive language. You have defined function as r_changed and using it as r_Changed
Use
r.Changed += new EventHandler(r_changed);
instead of
r.Changed += new EventHandler(r_Changed);
I'm pretty sure you'd know by now that C# is a case sensitive programming language.
This should work
static void r_Changed(object sender, EventArgs e)
{
Rectangle r = (Rectangle)sender;
Console.WriteLine("Value Changed: Length = {0}", r.Length);
}
Notice how r_Changed is capitals (r_changed is what you originally defined)
I would suggest using this because it is easier to read.
There is a little typo mistake in your code. It should be r_Changed instead of r_changed in the your Event Handler.
i.e write
static void r_Changed(object sender, EventArgs e)
in place of
static void r_changed(object sender, EventArgs e)
(Remember C# is Case-sensitive)
Related
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
Closed 4 years ago.
This question was caused by a typo or a problem that can no longer be reproduced. While similar questions may be on-topic here, this one was resolved in a way less likely to help future readers.
Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
Improve this question
I have a problem with the code in rec.Speechreconized += rec_Speachrecognized.
I have been looking for answers in the internet but it just won't work. I hope someone can help me.
namespace ai
{
public partial class Form1 : Form
{
SpeechSynthesizer s = new SpeechSynthesizer();
Choices list = new Choice {};
public Form1()
{
SpeechRecognitionEngine rec = new SpeechRecognitionEngine();
list.Add(new String[] {"Hello", "how are you"});
Grammar gr = new Grammar(new GrammarBuilder(list));
try
{
rec.RequestRecognizerUpdate();
rec.LoadGrammar(gr);
rec.SpeechRecognized += rec_Speachrecognized();
rec.SetInputToDefaultAudioDevice();
rec.RecognizeAsync(RecognizeMode.Multiple);
}
catch{return;}
s.Speak("Hi, I am Ms M, what can i help you?");
InitializeComponent();
}
public void Say(String h)
{
s.Speak(h);
}
private EventHandler<SpeechRecognizedEventArgs> rec_Speachrecognized(object sender, SpeechRecognizedEventArgs e)
{
string r = e.Result.Text;
if(r == "hello")
{
Say("hi");
}
throw new NotImplementedException();
}
private void Form1_Load(object sender, EventArgs e)
{
}
}
}
you need to change this line
rec.SpeechRecognized += rec_Speachrecognized();
to
rec.SpeechRecognized += rec_Speachrecognized;
basically remove the () at the end since the event will pass the params but this way you are calling the method without params
Closed. This question is not reproducible or was caused by typos. It is not currently accepting answers.
This question was caused by a typo or a problem that can no longer be reproduced. While similar questions may be on-topic here, this one was resolved in a way less likely to help future readers.
Closed 5 years ago.
Improve this question
I've searched this question here before asking and all of the answers seem to be people putting code after return break or others. I am having an issue where no matter what I put in an if statement, the code reads that it is unreachable.
private const double quarterPrice = 4.50;
private const double halfPrice = 7.50;
private const double fullPrice = 10.00;
private const double taxRate = .08;
private int orders = 0;
private double sales = 0;
private void btnFindMax_Click(object sender, EventArgs e)
{
if (quarterPrice > halfPrice)//if i put something in here, it is unreachable
{
int i = 1;//unreachable
if (quarterPrice > fullPrice)//unreachable
{
}
}
}
This is frustrating because I have nor idea why it's wrong, or what to do to fix it. It doesn't give me the red error underline, only the green suggestion line. However, when compiled, none of the code inside of the if statement executes.
I even tried to do:
private void btnFindMax_Click(object sender, EventArgs e)
{
if (quarterPrice < halfPrice)
{
Close();
}
}
And the code still didn't execute. I have no idea what is going on..
You have defined the variables as constants. The compiler knows that the condition in your if statement will never be true.
You have defined quarterPrice and halfPrice as constants. The compiler knows that quarterPrice will never be greater than halfPrice and is providing you with a warning.
For example you can generate the same warning like this.
if (false)
{
int i = 1;
// Do other work.
}
Closed. This question needs debugging details. It is not currently accepting answers.
Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
Closed 6 years ago.
Improve this question
I am building a program for my course in which i need global objects as i intend to have the object accessible from many forms and edited also. Before saying just use global variables i cant the specs state for use of OOP.
my latest attempt to fix this is using a public class but this gave a protection error problem
Code:
Form1.cs (forgot to rename and not re doing all the code and design)
public class ObjectsGlobal
{
Bays bay1 = new Bays();
Bays bay10 = new Bays();
}
frmInput.cs
private void btnAdd_Click(object sender, EventArgs e)
{
if ( 1 == Convert.ToInt32(nudBayNum))
{
ObjectsGlobal.bay1.CarMake = txtMake.Text;
}
}
any ideas are welcome at this point
Change it to:
public static class ObjectsGlobal
{
public static Bays bay1 = new Bays();
public static bay10 = new Bays();
}
Also, as recommended in a comment I have now read, take a look at the Singleton Pattern.
Closed. This question is not reproducible or was caused by typos. It is not currently accepting answers.
This question was caused by a typo or a problem that can no longer be reproduced. While similar questions may be on-topic here, this one was resolved in a way less likely to help future readers.
Closed 7 years ago.
Improve this question
So I am trying to learn how to use the StringBuilder Class. I read up about it and it seems amazing compared to string !
I am trying to create the StringBuilder in the other button but it keeps throwing me the error:
; expected" and Use of unassigned local variable "strb"
on line 42 & 43.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace WindowsFormsApplication15
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
string nrmlString = "C#";
nrmlString += " This";
nrmlString += " is";
nrmlString += " a";
nrmlString += " Test";
nrmlString += " Thisss";
MessageBox.Show(nrmlString);
}
private void button2_Click(object sender, EventArgs e)
{
StringBuilder strb new StringBuilder("something");
strb.Append("Something else");
MessageBox.Show(strb.ToString());
}
}
}
You missed one = in your button2_Click:
StringBuilder strb = new StringBuilder("something");
strb.Append("Something else");
#VargaDev,
Your error was a simple missing of the = in your code.
StringBuilder strb = new StringBuilder("something");
And it has already been answered. I just chimed in for a suggestion. When trying this type of codes, using VS and creating a form is cumbersome. Have a check at the wonderful (and free) utility LinqPad. You can use that as a code scratch pad. ie: For testing your code above, you would simply do this:
-Choose C# statements (or C# program) from the combo
-Type
StringBuilder strb = new StringBuilder("something");
strb.Append("Something else");
strb.ToString().Dump();
and hit F5. That is it! Dump() is on streoids. You can dump almost anything, it shows the result in a suitable way (a datagrid for example if it is a list like thing).
PS: I don't have any affiliation with the author of the utility (Joseph Albahari), just a lover of it. It is (and he is) worth to be appraised.
Closed. This question is not reproducible or was caused by typos. It is not currently accepting answers.
This question was caused by a typo or a problem that can no longer be reproduced. While similar questions may be on-topic here, this one was resolved in a way less likely to help future readers.
Closed 7 years ago.
Improve this question
Very new to C# and programming in general. I've run into this problem and I don't really know how to solve it. First of all, here's the code :
It says in the "if" parts of the code that random1 does not exist in the current context. Yes, I am aware that random only exists within the Button_click part because it is between brackets. The code is supposed to pick a random number between 0 and 20 without displaying it so that the user has to guess it. If the user is wrong, it shows a hint saying if the number is too high or too low. How can I fix this problem? Thanks
EDIT : It seems that I was too vague, your answers were good though. This is the full code :
public void Button_Click(object sender, RoutedEventArgs e) //random
{
Random chiffrealeatoire = new Random();
int random1 = (chiffrealeatoire.Next(0, 20));
}
private void Button_Click_1(object sender, RoutedEventArgs e) //quit
{
Application.Current.Shutdown();
}
private void Button_Click_2(object sender, RoutedEventArgs e) //veri
{
}
public void TextBox_TextChanged(object sender, TextChangedEventArgs e)
{
if (BoiteChiffre.Text < random1)
{
MessageBox.Show("Too low");
}
if (BoiteChiffre.Text > random1)
{
MessageBox.Show("Too high");
}
else
{
MessageBox.Show("Congratulations");
}
}
The user is supposed to write in the textbox
You've closed off your method and left out the if statement! The random1 variable is defined and declared within your method so it doesn't exist outside of it. Please move the method's closing bracket to include the if statement as well.
Also, your two if statements should really be linked together with an else if. You've declared two separate if statements so only one of them will have the else. Not wrong, just better practice to the following.
Basic structure:
public void Button_Click(object sender, RoutedEventArgs e) {
...
int random1
if(<random1) {
random1
} else if(>random1) {
...
} else {
...
}
} // <- method closing bracket
Edit: Since you've heavily modified the code provided I'll have to update my explanation.
Your issue has to do with variable scope. A variable defined within a method has local scope to that method. It's not accessible and doesn't even exist outside of it. You should be declaring your method OUTSIDE all the methods so that you can have multiple methods using it.
Basic structure:
int random1
public void methodA() {
random1 = whatever
}
public void methodB() {
if(random1) {
...
}
}
Please try the below code snippet. You need to declare the variable inside of the same method.
public void Button_Click(object sender, RoutedEventArgs e) //random
{
Random chiffrealeatoire = new Random();
int random1 = (chiffrealeatoire.Next(0, 20));
if (BoiteChiffre.Text < random1)
{
MessageBox.Show("Too low");
}
if (BoiteChiffre.Text > random1)
{
MessageBox.Show("Too high");
}
else
{
MessageBox.Show("Congratulations");
}
}