Develop Reference

How can I change the background of the a form from a second form?

I am using C# windows forms and I'm having a problem. I have a form which I want to change the background of, however, I want to do so from a second form. The second for has a button which when pressed, the background of the first form changes. Here is my code
First Form:
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)
{
Form2 frm2 = new Form2();
frm2.ShowDialog();
}
}
}
Second Form:
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 Form2 : Form
{
public Form2()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
Form1 frm1 = new Form1();
frm1.TransparencyKey = Color.Turquoise;
frm1.BackColor = Color.Turquoise;
}
}
}
The button is supposed to turn the first form transparent. This however, does not work. Am I missing something? Thank you!

You can set the Form 2's owner to Form1. Then access it's properties that way.
Form 1
private void button1_Click(object sender, EventArgs e)
{
Form2 frm2 = new Form2();
frm2.ShowDialog(this);
}
Form 2
private void button1_Click(object sender, EventArgs e)
{
Form1 frm1 = (Form1)this.Owner;
frm1.TransparencyKey = Color.Turquoise;
frm1.BackColor = Color.Turquoise;
}

You can do it using delegate and events or by implementing singleton in parent form.

Autoplay video on windows form

i am new to .net i am having trouble playing videos automatically. I would be showing different textboxes here but i want the video to autplay without any buttons
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;
using WMPLib;
namespace ThinkQDisplay
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void axWindowsMediaPlayer1_Enter(object sender, EventArgs e)
{
AxWindowsMediaPlayer1.URL = "C:\Users\Ramrod\Documents\Visual Studio 2012\Projects\ThinkQDisplay\ThinkQDisplay\sample.avi";
}
}
}
It keeps telling it is an unrecognized escape sequence. Also I would like to have a separate form (form2). Where I can choose what to play here on form 1. Is it also possible to have it looped?

private void axWindowsMediaPlayer1_Enter(object sender, EventArgs e)
{
axWindowsMediaPlayer1.URL = #"C:\Users\Ramrod\Documents\Visual Studio 2012\Projects\ThinkQDisplay\ThinkQDisplay\sampler.avi";
}
private void Form1_Load(object sender, EventArgs e)
{
axWindowsMediaPlayer1.settings.autoStart = true;
}
}
}

How do I make a variable accessible from every method of class?

I have an int named "mode". I want to make every function be able to access it.
Here is my code.
namespace WindowsFormsApplication1
{
public partial class Form5 : Form
{
public Form5()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
int wow = mode - 1;
}
private void Form5_Load(object sender, EventArgs e)
{
int mode = 4;
}
}
}

Just make it a property of the class.
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 Form5 : Form
{
public int mode {get; set;}
public Form5()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
int wow = mode - 1;
}
private void Form5_Load(object sender, EventArgs e)
{
mode = 4;
}
}
}

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 Form5 : Form
{
public int mode;
public Form5()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
int wow = mode - 1;
}
private void Form5_Load(object sender, EventArgs e)
{
mode = 4;
}
}
}
However, I'd be surprised if there wasn't a SO page about this. Also I'd recommend looking at MSDN and other programming c#.net resources.

Get/Set Variable

the goal of the program is to be able to use the get and set methods of variables.
I have this code in a project C#:
Form1:
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
{
private int c = 0;
public int a { get; set; }
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
a = 5;
Form2 f2 = new Form2();
f2.b = a;
f2.Show();
}
}
}
and in a Form2:
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 Form2 : Form
{
public Form2()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
Form1 f1 = new Form1();
MessageBox.Show(Convert.ToString(b));
}
}
}
This code not work because the value of b should be 5, but during execution value 0;
any solution?

You can't expect values of one instance to magically propagate to every other instance.
So doing this:
Form1 f1 = new Form1();
int b = f1.a;
Is always going to be 0. You created a new instance, and nothing has happened to it! If you want to get the existing form's value (where the button was presumably clicked) you need to pass it to Form2 somehow.
You can:
Pass it on the constructor of Form2
Set up a service that holds the data instead
Probably about a million other approaches

private void button1_Click(object sender, EventArgs e)
{
a = 5;
Form2 f2 = new Form2();
f2.b=a;
f2.Show();
}
public partial class Form2 : Form
{
public int b;
public Form2()
{
InitializeComponent();
}
}
You want to pass the data before showing the second form instead of after the fact.

Multiform DataGridView and DetailView Issues

I am trying to make a multiform application that takes a DataGridView of table attributes and shows them in a DetailView upon the click of a button. When I click the button and the second form opens it is empty. Then if I close the second form I get 'An unhandled exception of type 'System.NullReferenceException' occurred'. Here is my code:
Form 1
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 MultiForm
{
public partial class Form1 : Form2
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
// TODO: This line of code loads data into the 'personnelDataSet.employee' table. You can move, or remove it, as needed.
this.employeeTableAdapter.Fill(this.personnelDataSet.employee);
}
private void btnExit_Click(object sender, EventArgs e)
{
this.Close();
}
private void btnDetails_Click(object sender, EventArgs e)
{
Form2 dForm = new Form2();
dForm.ShowDialog();
this.tableAdapterManager.UpdateAll(this.personnelDataSet);
}
}
}
Form 2
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 MultiForm
{
public partial class Form2 : Form
{
//public Form2()
//{
// InitializeComponent();
//}
private void employeeBindingNavigatorSaveItem_Click(object sender, EventArgs e)
{
this.Validate();
this.employeeBindingSource.EndEdit();
this.tableAdapterManager.UpdateAll(this.personnelDataSet);
}
private void Form2_Load(object sender, EventArgs e)
{
// TODO: This line of code loads data into the 'personnelDataSet.employee' table. You can move, or remove it, as needed.
this.employeeTableAdapter.Fill(this.personnelDataSet.employee);
}
}
}
I get the exception on form 1 at this.tableAdapterManager.UpdateAll(this.personnelDataSet); Any help would be greatly appreciated.

Didn't drag in the data components into the tray duh... Sorry guys.