I have two forms (for example Form1 and Form2) in my project and I run only one form depending on a value which is read from a .txt file in Program.cs.
The two forms have the same controls and I am wondering if I can call the controls in a workerThread (inside the class Fsm.cs) using the same parent definition for both the forms.
For example: the control TextBox1 is defined in Form1 and Form2, but I want call in the workerThread DoWork() only the parent control associated to the running form:
parent.TextBox1.Visible = true;
Where parent can be Form1 or Form2.
How can I use the same parent definition mutually in Fsm.cs?
I don't want to define two different thread functions for the two forms.
Here there is the code:
public partial class Form1 : Form
{
public Form1()
{
form2 = new Form2();
InitializeComponent();
workerObject = new Fsm(this, form2);
Thread workerThread = new Thread(workerObject.DoWork);
}
}
public partial class Form2 : Form
{
public Form2()
{
form1 = new Form1();
InitializeComponent();
workerObject = new Fsm(form1, this);
Thread workerThread = new Thread(workerObject.DoWork);
}
}
public class Fsm
{
public Form1 parent;
public Form2 parent1;
public Fsm(Form1 p, Form2 p1)
{
parent = p;
parent1 = p1;
}
public void DoWork()
{
parent.TextBox1.Visible = true;
}
}
Thank you.
Related
In Form1 I have one DataGridView and multiple textboxes. When I click A button in Form2 I need to save the data from DataGridView and multiple textboxes to Database. How to Implement in C sharp Windows Application
Form1 Button Click event. I opened Form2
public sealed partial class form1 : Form
{
private static form1 instance = null;
public static form1 Instance
{
get
{
if (instance == null)
{
instance = new form1();
}
return instance;
}
}
private void button1_Click(object sender, EventArgs e)
{
textbox2.Text=100;
form2 CO = new form2();
CO.Show();
}
}
I want to attach textboxes data and Datagridview content to
object SO and Call InsertSale function .textboxes and datagridview are in form1
This is Button Click Event in Form 2
private void button1_Click(object sender, EventArgs e)
{
clsSale SO = new clsSale();
SO.Totamount = Convert.ToDecimal(form1.Instance.textBox2.Text);
SO.InserSale(SO);
}
If Form2 wants to access the Form1 properties.
Pass ParentForm instance to the ChildForm constructor. Add a public method in the parent form to update its properties from child form.
public partial class Form1: Form
{
public Form1()
{
InitializeComponent();
}
public void SetTextBoxValue(string val)
{
this.textBox1.Text = val;
}
private void CreateForm2()
{
var form2 = new Form2(this);
form2.Show();
}
}
public partial class Form2: Form
{
private Form1 form1;
public Form2(Form1 frm1)
{
InitializeComponent();
form1= frm1;
form1.SetTextBoxValue("Value from Form2");
}
}
Create a global class, such as Global.cs, in the project. Then declare the following variables:
public static Form1 frm1
public static Form2 frm2
Declare a variable of the Form class - Form frm1 or Form frm2 etc.
Now access the variables from any form as follows:
Global.frm1 = new Form1() // - for the Home Form1
Global.frm1.ShowDialog();
Global.frm2 = new Form2() // - for the Home Form1
Global.frm2.ShowDialog();
If you want to access a control in any form, just extend them as follows:
frm1.txtBox1.Text
frm2.button1.Click() // etc.
I know how to switch form to form, but my problem is that when switching from Form B to Form A. It always create a new Instance of Form A.
How can I avoid this behaviour?
What you are looking for is called Singleton.
For a very basic approach you can take this:
public partial class Form1 : Form
{
public static Form1 Instance { get; set; } //Create an Instance Object of your Window
public Form1()
{
InitializeComponent();
}
//Your call to open the Window
private void OpenForm2()
{
if (Form2.Instance == null)//Check if Form2 has already been created
{
//if not: go create a new one !
Form2.Instance = new Form2();
}
//Instance of Form2 is already created => open that one
Form2.Instance.Show();
}
}
public partial class Form2 : Form
{
public static Form2 Instance { get; set; }
public Form2()
{
InitializeComponent();
}
}
I use Form.Show() to open a new form
Like this:
public Form2()
{
Form1 fm = new Form1();
fm.Show();
}
How do I get Form2's name when Form1 has control?
What I am doing is create a public variable(ex.pFormname) in From1
and set pFormname = Form2 before the show common like this:
public Form2()
{
Form1.pFormname = "Form2";
Form1 fm = new Form1();
fm.Show();
}
Is there any other way except creating a public variable?
And is there any resource release should I do after closing Form1?
public Form2()
{
Form1 fm = new Form1();
Form1.pFormname = this.Text; // this = Form2, Text = the arbitrary name of the form.
fm.Show();
}
This requires you to have a public instance variable or property called pFormname in Form1 class. the 'this' keyword represents the current instance of Form2, and Text is the property which contains the name of the Form.
If you want to access other properties on the parent form, you could pass it as a reference when you instantiate Form1.
public Form2()
{
Form1 fm = new Form1(this); // this = form2.
fm.Show();
}
In Form1 you would have something like this:
public partial class Form1 : Form
{
private Form2 _parentForm;
public Form1(Form2 parentForm)
{
_parentForm = parentForm;
InitializeComponent();
}
}
And you would call public variables/properties/methods like this:
_parentForm.SomeMethod();
You could use the forms Owner property and pick that up in your instance later. For example in the constructor of Form2:
public Form2()
{
Form1 fm = new Form1 {Owner=this};
fm.Show();
}
You use the Owner name in Form1 like this
public class Form1 : Form
{
public Form1()
{
InitializeComponent();
this.Load += Form1_Load;
}
void Form1_Load(object sender, EventArgs e)
{
label1.Text += Owner.Name;
}
}
If you want to find the name of the parent form , you can do so by using
string s = ParentForm.Name; // s will contain the name of the parent form
Hope this helps..
If you want to find out , the child ..you can do so by:
MdiChildren property.
this will help you to find out , which child forms(Form 2) are contained by currently opened form(Form1).
Refer to this for how to use this exactly:
http://msdn.microsoft.com/en-us/library/system.windows.forms.form.mdichildren(v=vs.110).aspx
The best thing you can do in that situation is to have a private field in Form1 and set it equal to Form2 when you instantiate it like this.
class Form1 : Form
{
private Form _parentForm;
public Form1(Form f)
{
_parentForm = f;
}
}
and when you instantiate Form1 do like this
Form1 fm = new Form1(this) // in the constructor of Form2;
after this you will have the reference to the Form2 in the Form1's _parentForm variable and you can easuily access any of its properties for instance;
MessageBox.Show(_parentForm.Name) // in Form1 will show the name of Form2
or you can just have a string which you set the this.Name when you instantiate Form1 in Form2's constructor
class Form1 : Form
{
private string _parentFormName;
public Form1(string name)
{
_parentForm = f;
}
}
Form1 fm = new Form1(this.Name) // in the constructor of Form2;
and then you can directly call that variable like this
MessageBox.Show(_parentFormName);
I am trying to return some data from Form2 to Form1, everything seems fine, I got the data and so, but, when I try to pass my data to a textbox, it doesn't changes the text. Only if I open a new instance of Form1, on Form2 it works. Why this happen? Can't I send the text to the old instance?
I'm using this code;
Form1 (Main Form)
public void updateText(string data)
{
MessageBox.Show(data);
txtGood.Text = data;
}
Form2 SecondaryForm = new Form2();
SecondaryForm.ShowDialog();
Form2 (Second Form with user data)
Form1 MainForm = new Form1();
MainForm.updateText(data);
MainForm.ShowDialog();
this.Close();
So, my question is, how can I pass the data values to the old instance of the main form? without having to create a new instance and show a new instance. Is there a way to do this?
This is because you're creating a instance of Form1 in your Form2 code. What you want to do is setup Form2's parentForm to be the instance of the Form1 that created it.
public partial class Form1 : Form
{
public void CreateForm2()
{
Form2 form2 = new Form2(this);
form2.ShowDialog();
}
public string MyTextboxText
{
get { return txtMyTextbox.Text; }
set { txtMyTextbox.Text = value; }
}
}
public partial class Form2 : Form
{
private Form1 parentForm;
public Form2(Form1 parentForm)
{
this.parentForm = parentForm;
}
public void myButtonClick()
{
parentForm.MyTextboxText = "Hello";
}
}
This code is just an example, probably wont compile as-is.
What you can do is pass the reference of MainForm(Form1) to second Form(Form2). Then instead of creating MainForm again use the reference to update the textbox.
//pass reference to form2
Form2 SecondaryForm = new Form2(mainForm);
SecondaryForm.ShowDialog();
//in the constructor of Form2 save the reference of Form1
Form1 form1 = null
Form2(Form1 mainForm)
{
form1 = mainForm;
}
//then instead of creating a new MainForm again just use reference of Form1
form1.updateText(data);
this.Close()
main form:
private void Button2_Click(object sender, EventArgs e) {
frmCustomersRecord rec = new frmCustomersRecord(this);
rec.ShowDialog();
rec.GetData();
}
child form:
public partial class frmCustomersRecord : Form
{
public frmCustomersRecord()
{
//blank contructor (Instance of an class)
}
frmCustomerDetails cd;
public frmCustomersRecord(frmCustomerDetails parentForm) : this()
{
this.cd = parentForm;
}
//call the methods using child form object
}
form A opens form B, and form A.visible = false;
form A has a public int variable and I need controls in form B to be able to access and modify this variable. could this be done as passing the value through the constructor is only one way!
and so if it could be done, if form A is not visible could the value still be accessed?
(form b is not supposed to be dialog!)
many thanks!
edited: I do not quite get the explanations actually. so far it is like that:
in form a:
//in global space
public int temp = 123;
//in form_load event
Form setup = new setup();
setup.Show();
this.Visible = false;
in form setup:
//in form_load event
textBox1.text = temp.toString();
//in button_press event
form a.temp = "456";
I hope I have explained my stance clearly!
First, have member field in form B of type form A:
private FormA parent;
Second, have such constructor in form B:
public FormB(FormA parent)
: this()
{
this.parent = parent;
}
Now when you create instance of form B, pass reference to the running form A instance:
FormB formB = new FormB(this);
formB.Show();
And you can access the public property through the parent field e.g.
//inside Form B code..
public Foo()
{
parent.PUblicProp = "Hello";
}
this is one way to pass values from one form to another form
public partial class Form2 : Form
{
public string MyProperty { get; set; }
public Form2()
{
InitializeComponent();
}
private void Form2_Load(object sender, EventArgs e)
{
label1.Text = MyProperty;
}
}
after that in the button click event handler in Form1
add the following code
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
Form2 form2 = new Form2();
form2.MyProperty = "This is from Form1";
form2.Show();
}
}
Since your int variable is public then your controls in formB can access and modify it, formA visibility won't affect this it will be accessed disregarding the visibility of it:
FormA f = new FormA();
int newValue = f.yourintvariable;
And there are a lot of alternative ways like using constructor to send the variable in the FormA constructor and initialize it from FormB,
or you can define it as static but in this case will be one variable for all the instances of thid form