CODEWITHSUNDEEP
c#winforms
Sumit
Sumit

Reputation: 277

Update control and refresh form by call from class to main form

I want to update text box while doing something in other class. Let me put my code :

Form1.cs

namespace TestApp
{
    public partial class Form1 : Form
    {
        CalledClass call = new CalledClass();

        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            call.Call_UpdateBox();
        }

        public void UpdateBox()
        {
            textBox1.Text = "hello";
        }
    }
}

CalledClass.cs

namespace TestApp
{
    class CalledClass
    {
     public void Call_UpdateBox()
        {
            Form1 mainform = new Form1();

            //do looping for doing some tasks here and update textbox every time
            mainform.UpdateBox();
        }
    }
}

The Call_UpdateBox function in CalledClass is called when the button on main form is clicked, where I have to do some looping and in between update the textbox in the main form. Though textbox gets updated if i see its value in debug mode, but it reamins blank on main form. Please suggest. Thx in advance.

Upvotes: 1

Views: 13425

Answers (4)

Peuczynski
Peuczynski

Reputation: 4733

The simpliest way

namespace TestApp
{
    public partial class Form1 : Form
    {
        CalledClass call = new CalledClass();

        public Form1()
        {
            InitializeComponent();
            call.FormH = this;
        }

        private void button1_Click(object sender, EventArgs e)
        {
            call.Call_UpdateBox();
        }

        public void UpdateBox()
        {
            textBox1.Text = "hello";
        }
    }
}

namespace TestApp
{
    class CalledClass
    {
        public static Form1 FormH;

        public void Call_UpdateBox()
        {
            //do looping for doing some tasks here and update textbox every time
            FormH.UpdateBox();
        }
    }
}

Upvotes: 2

RMalke
RMalke

Reputation: 4094

You can use Threads but a simpler way, since you are in WindowsForms is to use a BackgroundWorker,

Your Form1 would be some like:

public partial class Form1 : Form
{
    BackgroundWorker _bw = new BackgroundWorker();
    CalledClass call = new CalledClass();

    public Form1()
    {
        InitializeComponent();

        bw.DoWork += bw_DoWork;
        bw_ProgressChanged += bw_ProgressChanged;
    }

    private void button1_Click(object sender, EventArgs e)
    {
        if (bw.IsBusy != true)
        {
            bw.RunWorkerAsync();
        }
    }

    private void bw_DoWork(object sender, DoWorkEventArgs e)
    {
        call.Call_UpdateBox();
    }

    private void bw_ProgressChanged(object sender, ProgressChangedEventArgs e)
    {
        textBox1.Text = "hello";

        // Here you can access some progress property from CalledClass in order to monitor and inform progress
    }
}

Upvotes: 1

ken2k
ken2k

Reputation: 48985

You are creating a new form instance, and you don't even show it. So you're not calling UpdateBox() on the good object instance.

Instead, re-use your current instance of your mainForm. For example:

public void Call_UpdateBox(Form1 targetForm)
{
    targetForm.UpdateBox();
}

private void button1_Click(object sender, EventArgs e)
{
    call.Call_UpdateBox(this);
}

Upvotes: 2

DonBoitnott
DonBoitnott

Reputation: 11025

You're declaring a new instance of Form1, not referencing the one that already exists. You should:

namespace TestApp
{
    public partial class Form1 : Form
    {
        CalledClass call = new CalledClass();

        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            call.Call_UpdateBox(this);
        }

        public void UpdateBox()
        {
            textBox1.Text = "hello";
        }
    }
}
namespace TestApp
{
    class CalledClass
    {
     public void Call_UpdateBox(Form1 Sender)
        {
            //do looping for doing some tasks here and update textbox every time
            sender.UpdateBox();
        }
    }
}

Upvotes: 5

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