using form controls in other objects

John Rogers

I am trying to test running a threadpool timer in a class outside of a form class and have the event from the timer create a message in a texBox in my main Form. Not sure teh best way to do this...I can't see the textBox in the other object...

I can easily instantiate the object and start teh timer in a method from that object....but not sure how to create the event, AND use it in the code runnig in the Form.

I am working up to learning how to run a time consuming process (IO of course) in a separate thread then pass buffers of data to the form....and I 'm trying to start simple...no luck so far on the simple part...

Thanks

5 Replies

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Stefan17y ago
Accepted answer
To get the text box from the other form, you can just make it public. Or, you can create a property for the text box. If you want a more specific answer, please post your code.

Hope this helps!
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John Rogers17y ago

Hey...I tried putting the timer event in to the Form and accessing a callback method within...and STILL can no t get to the textBox1 control.

Obviously, I am missing something VERY elemetary at this point. Any ideas for teh newbiw are appreciated.

JPR

namespace TimerForm

{

public partial class Form1

{

///

/// Required designer variable.

///

public System.ComponentModel.IContainer components = null;

///

/// Clean up any resources being used.

///

/// true if managed resources should be disposed; otherwise, false.

protected override void Dispose(bool disposing)

{

if (disposing && (components != null))

{

components.Dispose();

}

base.Dispose(disposing);

}

#region Windows Form Designer generated code

///

/// Required method for Designer support - do not modify

/// the contents of this method with the code editor.

///

private void InitializeComponent()

{

this.button1 = new System.Windows.Forms.Button();

this.button2 = new System.Windows.Forms.Button();

this.textBox1 = new System.Windows.Forms.TextBox();

this.SuspendLayout();

//

// button1

//

this.button1.Location = new System.Drawing.Point(12, 25);

this.button1.Name = "button1";

this.button1.Size = new System.Drawing.Size(75, 23);

this.button1.TabIndex = 0;

this.button1.Text = "Start";

this.button1.UseVisualStyleBackColor = true;

this.button1.Click += new System.EventHandler(this.button1_Click);

//

// button2

//

this.button2.Location = new System.Drawing.Point(12, 221);

this.button2.Name = "button2";

this.button2.Size = new System.Drawing.Size(75, 23);

this.button2.TabIndex = 0;

this.button2.Text = "Quit";

this.button2.UseVisualStyleBackColor = true;

this.button2.Click += new System.EventHandler(this.button2_Click);

//

// textBox1

//

this.textBox1.Location = new System.Drawing.Point(12, 54);

this.textBox1.MinimumSize = new System.Drawing.Size(0, 50);

this.textBox1.Multiline = true;

this.textBox1.Name = "textBox1";

this.textBox1.Size = new System.Drawing.Size(207, 161);

this.textBox1.TabIndex = 1;

//

// Form1

//

this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);

this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;

this.ClientSize = new System.Drawing.Size(289, 266);

this.Controls.Add(this.textBox1);

this.Controls.Add(this.button2);

this.Controls.Add(this.button1);

this.Name = "Form1";

this.Text = "Form1";

this.Load += new System.EventHandler(this.Form1_Load);

this.ResumeLayout(false);

this.PerformLayout();

}

#endregion

private System.Windows.Forms.Button button1;

private System.Windows.Forms.Button button2;

public System.Windows.Forms.TextBox textBox1;

}

}

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 TimerForm

{

public partial class Form1 : Form

{

// field definitions

public string aString;

public Form1()

{

InitializeComponent();

// TestClass newObject = new TestClass();

}

private void Form1_Load(object sender, EventArgs e)

{

aString = "Load Form\r\n";

textBox1.Text = aString;

}

private void button1_Click(object sender, EventArgs e)

{

aString += "Start Application\r\n";

textBox1.Text = aString;

}

private void button2_Click(object sender, EventArgs e)

{

aString += "Stop Application\r\n";

textBox1.Text = aString;

this.Close();

}

static void dTick(object data)

{

for (int i = 0; i < 1000; i++);

Form1.textBox1.Text = data;

}

static void Main()

{

System.Threading.Timer tmr = new System.Threading.Timer(dTick,"state 1...",3000,1000);

Application.Run(new Form1());

tmr.Dispose();

}

}

}
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John Rogers17y ago
Ok...I moved a simple thread pool based timer into my form code...

Added a button whose click event starts a timer which has an event defined as dTick.

Try to access a public textBox control...in dTick() and can not see the control.

I can see it in other event methods in the Form1 but not in the dTick

private void buttonTimerTest_Click(object sender, EventArgs e)

{

System.Threading.Timer tmr = new System.Threading.Timer(dTick, "tick...", 5000, 1000);

textBoxSetUPTabStatusMessage.Text = "started...";

}

private void dTick(object data)

{

//MainForm. //writes "tick..." to the console...

}

// private void SendRptsBtn_Click()

//-------------------------------------------
0
Stefan17y ago
The problem is that in order to access the text box, you must create a new instance of the form1 class: "Form1 frm = new Form1();", and then try to access the text box. If you do this you will be able to access the text box.

Here's the catch: If you create a new instance of your form, you will not be accessing the current form. Communicating with a form that is already open can sometimes be difficult.

A simple fix would be to just move the event into your form ,which I don't think you want, so you may want to look up what delegates are and how to use them.

Hope this helps!
0
John Rogers17y ago
I did make the textBOX control public...whcih is why I'm confused that I can't see it to set the Text property when ready. I tried using the Form1. qualifier and it does not offer me access to any controls.

I may try to create a property in my form that I can set with a new text string.

Here is the code:

Form:

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 TimerForm

{

public partial class Form1 : Form

{

public string aString;

public Form1()

{

InitializeComponent();

//TestClass newObject = new TestClass();

}

private void Form1_Load(object sender, EventArgs e)

{

aString = "Load Form\r\n";

textBox1.Text = aString;

}

private void button1_Click(object sender, EventArgs e)

{

aString += "Start Application\r\n";

textBox1.Text = aString;

}

private void button2_Click(object sender, EventArgs e)

{

aString += "Stop Application\r\n";

textBox1.Text = aString;

this.Close();

}

static void Main()

{

TestClass TTT = new TestClass();

TTT.TimerStart();

Application.Run(new Form1());

}

}

}

Class:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading;

namespace TimerForm

{

public class TestClass

{

public void TimerStart()

{

System.Threading.Timer t = new System.Threading.Timer(dTick, "Tick...", 5000, 1000);

}

public void dTick(object data)

{

for (int i = 0; i < 1000; i++) ;

Form1. here

}

}

}

Thanks
0