I have had a fairly thorough look around, but couldn't find anything related, so I have decided to ask here :)
I have created a WinForm in Visual Studio, and in its code it has a fair few functions. At this point its all working nicely. I then go and put
Application.ApplicationExit += new EventHandler(Application_ApplicationExit);
in the constructor function and when I go and click the little cross in the corner, I have to click it twice for it to close! I would put the code in here, but its 240 lines, so its kinda huge.. If you need to see it though, I can put it up.
Thanks in advance!
Dronnoc
The ApplicationExit event is automaticly called on clicking the cross. So there is actual no need to call it. What do you want to do on closing?
If you want some action between clicking the cross and shutdown, you have to call the FormClosing() event.
I have solved it peoples!
I had a ListBox on the page, and a function running when the SelectedIndex changed. When i closed the form, it passed a SelectedIndex of -1, and then closed the second time. So, in order to fix it, I simply put some simple verification of the value on the ListBox function.
Example:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace WindowsFormsApplication3
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
listBox1.SelectedIndexChanged += new EventHandler(listBox1_SelectedIndexChanged);
}
void listBox1_SelectedIndexChanged(object sender, EventArgs e)
{
}
}
}
becomes
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace WindowsFormsApplication3
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
listBox1.SelectedIndexChanged += new EventHandler(listBox1_SelectedIndexChanged);
}
void listBox1_SelectedIndexChanged(object sender, EventArgs e)
{
if(listBox1.SelectedIndex == -1)
{
Application.Exit();
}
//Rest of the code goes here.
}
}
}
Related
I am trying to create a dialogue box that contains 3 radio buttons and a "Present" button to be used with some projector software we have. What I want to do is, after clicking "Present", open a file specific to which room was chosen with the radio buttons.
The issue is, after clicking "Present" nothing happens.
I know Process.Start and present_Click are correct; in a test project I did the "Present" button successfully opens a file. I am sure the CheckedChanged parts are probably incorrect, but I am confused as to what to do with them.
Here's my code:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Diagnostics;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
public void present_Click(object sender, EventArgs e)
{
if (room1.Checked)
{
System.Diagnostics.Process.Start(#"room1.txt");
}
else if (room2.Checked)
{
System.Diagnostics.Process.Start(#"room2.txt");
}
else if (room3.Checked)
{
System.Diagnostics.Process.Start(#"room3.txt");
}
}
private void room1_CheckedChanged(object sender, EventArgs e)
{
room1.Checked = true;
}
private void room2_CheckedChanged(object sender, EventArgs e)
{
room2.Checked = true;
}
private void room3_CheckedChanged(object sender, EventArgs e)
{
room3.Checked = true;
}
}
Can someone please help me with these radio buttons?
Your CheckedChanged event handlers are definitely messed up.
In english, your logic says
Anytime a radio button's checked status is changed, set its checked property to true
Honestly I'm surprised you don't get into some infinite loop where every control is fighting to be the "selected one". Removing that logic altogether may well fix your problem. It also seems odd that you are "starting" a text file, but I assume that is intentional.
The important knowledge here is that a user clicking the radio button automatically sets the Checked property. There is no need to do it yourself in code-behind.
I think you need to remove the events which trigger upon checking or unchecking. If I understand properly, you only want 'something' to happen when you click Present. So once someone clicks Present, then verify which checkboxes are on/off and do the appropriate thing:
Sorry if I'm making the wrong assumptions, feel free to correct.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Diagnostics;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
public void present_Click(object sender, EventArgs e)
{
if (room1.Checked)
{
System.Diagnostics.Process.Start(#"room1.txt");
}
else if (room2.Checked)
{
System.Diagnostics.Process.Start(#"room2.txt");
}
else (room3.Checked)
{
System.Diagnostics.Process.Start(#"room3.txt");
}
}
}
}
This question already has answers here:
Why is there a default instance of every form in VB.Net but not in C#?
(2 answers)
c# Show Windows Form
(4 answers)
Closed 9 years ago.
So I have a Windows Form named Settings.CS
It has nothing.. the code is only this much
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace SteamBot
{
public partial class Settings : Form
{
public Settings()
{
InitializeComponent();
}
}
}
Then I have another CLASS named Bot.CS. What I want to do is, after a specific function, I want the settings form to become visible. In VB it was just Settings.Visible = true
How do I do this in C#? Please help me.
Solution 1: if you want to display the Settings Form first time, you need to create an instance variable of that Form and call ShowDialog() method to display it.
Try This:
void SpecificFunction()
{
//--at the end of MyFunction call settings form
Settings frmSettings=new Settings();
frmSettings.ShowDialog();
}
Solution 2: if you want to display the Settings Form which was hidden before , you need to to follow the below steps make it Visible.
Step 1: identify/obtain the Settings Form by using Application.OpenForms[] Collection.
Step 2: create a new instance variable of a Form by casting the obtained Settings Form in above step.
Step 3: Call the Show() Method on the created instance variable to Show/Display the Settings form.
Try This:
void SpecificFunction()
{
//--at the end of MyFunction call settings form
Form frmSettings = (Settings) Application.OpenForms["Settings"];
frmSettings.Show();
}
Lets assume that Specific Function is a button click
private void Button1_Click(Object sender, EventArgs e )
{
Form1 myForm = new Form1();
myForm.Show();
}
Replace Form1 with the form name of your settings form !
I just created this new Form which is shown when the button is clicked:
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 WindowsFormsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
Form f2 = new Form();
f2.Visible = true;
//f2.Show(); also works
}
}
}
You can also use 'this' if you want to manipulate the instance
give it a try
How to use MessageBox in class library?
Here is my code
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 MessageBoxes
{
class ShowInfo
{
MessageBox.Show("test");
}
}
i can load MessageBox but can't have show property, MessageBox.Show("test"); <-- fail
You should NOT use a Windows forms MessageBox inside a class library. What if you use this library in an ASP.NET application. The MessageBox will be shown in Webserver. And your webserver will be waiting (hung) untill someone responds to that MessageBox in webserver.
An ideal design would be that you either return the message as string and deal with that string in caller specific way or throw an exception if thats what you want.
If you still want then here is your code corrected
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 MessageBoxes
{
class ShowInfo
{
public void ShowMessage(string msg)
{
MessageBox.Show(msg);
}
}
}
You have the call to messagebox outside any method.
This code cannot be compiled at all.
You should write
namespace MessageBoxes
{
class ShowInfo
{
public void ShowUserMessage(string messageText)
{
MessageBox.Show(messageText);
}
}
}
and then call it after instancing an object of type ShowInfo
ShowInfo info = new ShowInfo();
info.ShowUserMessage("This is a Test");
Additional Answer to this Question:
After the Class Library Project has been created.
Right Click your Project Add > New Item > Windows form
it's done by adding reference System.Windows.Forms.dll
Make sure you actually use the the class in the main form.
class ShowInfo
{
public static void show()
{
System.Windows.Forms.MessageBox.Show("test");
}
}
...
public Form1()
{
InitializeComponent();
ShowInfo.show();
}
I already follow the tutorial of adding sound in the c# but it cannot play the sound, but it is no error. How can I do?
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Media;
namespace WindowsFormsApplication2
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
SoundPlayer myPlayer = new SoundPlayer(WindowsFormsApplication2.Properties.Resources.sound1);
myPlayer.PlayLooping();
}
}
}
Make sure that you have the Form1_Load() assigned to the Form Load event. I've put in your code, and it works just fine.
To assign the event, just look at the following image..
This will ensure that the Form1_Load() is called when the form loads.
After having tested to see what would happen when you try to pass a non-.WAV file to the SoundPlayer, it WOULD produce an error:
Error 1 The best overloaded method match for 'System.Media.SoundPlayer.SoundPlayer(string)' has some invalid arguments.
This leads me to believe the code isn't being called.
I added a CSharp Class to a form project. Now I want to access the form controls from the Class.
I am using this piece of code with the implicit var as follows:
var form = frmClasses.ActiveForm as frmClasses;
Using this code, I set the form Modifiers to public, place the code is a method/function and I am able to access the form controls in the class.
The problem is each time I need to call a form control I have to use the var and the entire line of code above. Is there a simpler way that is less redundant?
Example: Each method/function in a the class will need to call the form controls thus referencing the form controls using Var.
Take a look at the code below, you will noticed that I am using Var to call each form control.
Code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;
namespace Classes
{
class ClsProperties
{
//VALIDATE TEXTBOX
public static void validateTextBox()
{
var form = frmClasses.ActiveForm as frmClasses;
if (form.txtMyTextBox.Text.Trim().Length == 0)
{
form.txtMyTextBox.BackColor = Color.Aquamarine;
}
}
//VALIDATE RADIO BUTTON
public static void validateRadio()
{
var form = frmClasses.ActiveForm as frmClasses;
if (form.radBtnColor.Checked == false)
{
form.lblShowError.ForeColor = Color.Aquamarine;
}
}
}
}
Form Code:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace Classes
{
public partial class frmClasses : Form
{
public frmClasses()
{
InitializeComponent();
}
private void btnSubmit_Click(object sender, EventArgs e)
{
ClsProperties.validateRadio();
ClsProperties.validateTextBox();
}
}
}
I could put all the validation in one method but I am simply trying to show how I would call multiple methods using a class.
Is there a better way to access the form elements in a class?
Merci