TreeView nodes from other form - c#

I have a TreeView with dinamically created nodes.
I want to reach the nodes from other form, when i close the other form.
But it does not work.
Sample:
form1
//show the other form (form2)
private void button1_Click(object sender, EventArgs e)
{
using (Form1 form1 = new Form1())
{
using (Form2 form2 = new Form2(form1))
{
form2.StartPosition = FormStartPosition.CenterParent;
form2.ShowDialog();
}
}
}
//call this method from other form (form2) when close
internal void example()
{
MessageBox.Show(treeView1.Nodes.Count.ToString());
}
//create the nodes
private void Form1_Load(object sender, EventArgs e)
{
TreeNode node = new TreeNode("aaaa");
treeView1.Nodes.Add(node);
node = new TreeNode("bbbb");
treeView1.Nodes.Add(node);
node = new TreeNode("cccc");
treeView1.Nodes.Add(node);
}
form2
public partial class Form2 : Form
{
Form1 form1;
public Form2(Form1 form1)
{
InitializeComponent();
this.form1 = form1;
}
private void button1_Click(object sender, EventArgs e)
{
this.Close();
form1.example();
}
}
MessageBox.Show(treeView1.Nodes.Count.ToString());
result: 0

Problem is in this line:
using (Form1 form1 = new Form1())
you're sending new instance of Form1 to your Form2. You should send current instance of Form1, like this:
private void button1_Click(object sender, EventArgs e)
{
using (Form2 form2 = new Form2(this))
{
form2.StartPosition = FormStartPosition.CenterParent;
form2.ShowDialog();
}
}

You construct Form1 twice. Once to show a form with a button. When the button is pressed you create another instance of Form1. This second instance is given to Form2. But... the Load event of the second instance is never called, meaning its tree is never filled. The Load event is only called when the form is displayed, and this instance is never displayed.
I suggest you follow the answer of Nino.
Or... if you insist to have multiple instances of Form1, move the code which fills the tree, inside the constructor of Form1, not in the Load-eventhandler.

Related

how to keep a form activated

Now, I have two forms, called form1 and form2, in the form1 there's a button, when I click it, then open the form2
private void button1_Click(object sender, EventArgs e)
{
Ges.produit.Add(p);
Form3 f= new Form3();
f.dataGridView1.Rows.Clear();
foreach (var item in Ges.produit)
{
f.dataGridView1.Rows.Add(item.Id, item.Name, item.Qty, item.Prac, item.Prav, item.Disc);
}
this.MdiParent = f.MdiParent;
f.Show();
this.Hide();
}
Question: in the form2, I created a button when I click it, the form2 close and get back to form1 without opening another form1 . How to do?this
You can do this a few ways, one way is to pass a reference of the parent form to the child form in its constructor, and then when you close the child form call show against this reference.
Another way to accomplish this is when you create the child form inside the parent form, at the same time also wire up the FormClosed event of the child form to re-display the parent form.
The following is an example for both of these methods
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void btnShowForm2_Click(object sender, EventArgs e)
{
var form2 = new Form2(this);
this.Hide();
form2.Show();
}
private void btnShowForm3_Click(object sender, EventArgs e)
{
var form3 = new Form3();
form3.FormClosed += (o, args) =>
{
this.Show();
};
this.Hide();
form3.Show();
}
}
public partial class Form2 : Form
{
private readonly Form1 _form1;
public Form2()
{
InitializeComponent();
}
public Form2(Form1 form1)
:this()
{
_form1 = form1;
}
private void Form2_FormClosed(object sender, FormClosedEventArgs e)
{
_form1.Show();
}
}

Send BackColor value to another form [duplicate]

I want to pass values between two Forms (c#). How can I do it?
I have two forms: Form1 and Form2.
Form1 contains one button. When I click on that button, Form2 should open and Form1 should be in inactive mode (i.e not selectable).
Form2 contains one text box and one submit button. When I type any message in Form2's text box and click the submit button, the Form2 should close and Form1 should highlight with the submitted value.
How can i do it? Can somebody help me to do this with a simple example.
There are several solutions to this but this is the pattern I tend to use.
// Form 1
// inside the button click event
using(Form2 form2 = new Form2())
{
if(form2.ShowDialog() == DialogResult.OK)
{
someControlOnForm1.Text = form2.TheValue;
}
}
And...
// Inside Form2
// Create a public property to serve the value
public string TheValue
{
get { return someTextBoxOnForm2.Text; }
}
private void button1_Click(object sender, EventArgs e)
{
Form2 frm2 = new Form2(textBox1.Text);
frm2.Show();
}
public Form2(string qs)
{
InitializeComponent();
textBox1.Text = qs;
}
Define a property
public static class ControlID {
public static string TextData { get; set; }
}
In the Form1
private void button1_Click(object sender, EventArgs e)
{
ControlID.TextData = txtTextData.Text;
}
Getting the data in Form1 and Form2
private void button1_Click(object sender, EventArgs e)
{
string text= ControlID.TextData;
}
After a series of struggle for passing the data from one form to another i finally found a stable answer. It works like charm.
All you need to do is declare a variable as public static datatype 'variableName' in one form and assign the value to this variable which you want to pass to another form and call this variable in another form using directly the form name (Don't create object of this form as static variables can be accessed directly) and access this variable value.
Example of such is,
Form1
public static int quantity;
quantity=TextBox1.text; \\Value which you want to pass
Form2
TextBox2.Text=Form1.quantity;\\ Data will be placed in TextBox2
Declare a public string in form1
public string getdata;
In button of form1
form2 frm= new form2();
this.hide();
form2.show();
To send data to form1 you can try any event and code following in that event
form1 frm= new form1();
form1.getdata="some string to be sent to form1";
Now after closing of form2 and opening of form1, you can use returned data in getdata string.
I've worked on various winform projects and as the applications gets more complex (more dialogs and interactions between them) then i've started to use some eventing system to help me out, because management of opening and closing windows manually will be hard to maintain and develope further.
I've used CAB for my applications, it has an eventing system but it might be an overkill in your case :) You could write your own events for simpler applications
Form1 Code :
private void button1_Click(object sender, EventArgs e)
{
Form2 f2 = new Form2();
f2.ShowDialog();
MessageBox.Show("Form1 Message :"+Form2.t.Text); //can put label also in form 1 to show the value got from form2
}
Form2 Code :
public Form2()
{
InitializeComponent();
t = textBox1; //Initialize with static textbox
}
public static TextBox t=new TextBox(); //make static to get the same value as inserted
private void button1_Click(object sender, EventArgs e)
{
this.Close();
}
It Works!
declare string in form1
public string TextBoxString;
in form1 click event add
private void button1_Click(object sender, EventArgs e)
{
Form1 newform = new Form1();
newform = this;
this.Hide();
MySecform = new Form2(ref newform);
MySecform.Show();
}
in form2 constructer
public Form2(ref Form1 form1handel)
{
firstformRef = form1handel;
InitializeComponent();
}
in form2 crate variable Form1 firstformRef;
private void Submitt_Click(object sender, EventArgs e)
{
firstformRef.TextBoxString = textBox1.Text;
this.Close();
firstformRef.Show();
}
In this code, you pass a text to Form2. Form2 shows that text in textBox1.
User types new text into textBox1 and presses the submit button.
Form1 grabs that text and shows it in a textbox on Form1.
public class Form2 : Form
{
private string oldText;
public Form2(string newText):this()
{
oldText = newText;
btnSubmit.DialogResult = DialogResult.OK;
}
private void Form2_Load(object sender, EventArgs e)
{
textBox1.Text = oldText;
}
public string getText()
{
return textBox1.Text;
}
private void textBox1_KeyUp(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter)
{
DialogResult = System.Windows.Forms.DialogResult.OK;
}
}
}
And this is Form1 code:
public class Form1:Form
{
using (Form2 dialogForm = new Form2("old text to show in Form2"))
{
DialogResult dr = dialogForm.ShowDialog(this);
if (dr == DialogResult.OK)
{
tbSubmittedText = dialogForm.getText();
}
dialogForm.Close();
}
}
Ok so Form1 has a textbox, first of all you have to set this Form1 textbox to public in textbox property.
Code Form1:
Public button1_click()
{
Form2 secondForm = new Form2(this);
secondForm.Show();
}
Pass Form1 as this in the constructor.
Code Form2:
Private Form1 _firstForm;
Public Form2(Form1 firstForm)
{
_firstForm = firstForm:
}
Public button_click()
{
_firstForm.textBox.text=label1.text;
This.Close();
}
you can pass as parameter the textbox of the Form1, like this:
On Form 1 buttom handler:
private void button2_Click(object sender, EventArgs e)
{
Form2 newWindow = new Form2(textBoxForReturnValue);
newWindow.Show();
}
On the Form 2
public static TextBox textBox2; // class atribute
public Form2(TextBox textBoxForReturnValue)
{
textBox2= textBoxForReturnValue;
}
private void btnClose_Click(object sender, EventArgs e)
{
textBox2.Text = dataGridView1.CurrentCell.Value.ToString().Trim();
this.Close();
}
Constructors are the best ways to pass data between forms or Gui Objects you can do this.
In the form1 click button you should have:
Form1.Enable = false;
Form2 f = new Form2();
f.ShowDialog();
In form 2, when the user clicks the button it should have a code like this or similar:
this.Close();
Form1 form = new Form1(textBox1.Text)
form.Show();
Once inside the form load of form 1 you can add code to do anything as you get the values from constructor.
How to pass the values from form to another form
1.) Goto Form2 then Double click it. At the code type this.
public Form2(string v)
{
InitializeComponent();
textBox1.Text = v;
}
2.) Goto Form1 then Double click it. At the code type this.
//At your command button in Form1
private void button1_Click(object sender, EventArgs e)
{
Form2 F2 = new Form2(textBox1.Text);
F2.Show();
}
This is very simple.
suppose you have 2 window form Form1 and Form2 and you want to send record of textbox1 from Form1 to Form2 and display this record in label1 of Form2;
then in Form2 create a label which name is label1 and go to the property of label1 and set 'Modifiers'=public and in Form one create a textBox with id textBox1 and a button of name submit then write the following code on button click event
button1_Click(object sender, EventArgs e)
{
Form2 obj=new Form2();
obj.label1.text=textBox1.text.ToString();
obj.show();
}
thats it...
for this way you can bind dataset record to another form's datagridview......
You can make use of a different approach if you like.
Using System.Action (Here you simply pass the main forms function as the parameter to the child form like a callback function)
OpenForms Method ( You directly call one of your open forms)
Using System.Action
You can think of it as a callback function passed to the child form.
// -------- IN THE MAIN FORM --------
// CALLING THE CHILD FORM IN YOUR CODE LOOKS LIKE THIS
Options frmOptions = new Options(UpdateSettings);
frmOptions.Show();
// YOUR FUNCTION IN THE MAIN FORM TO BE EXECUTED
public void UpdateSettings(string data)
{
// DO YOUR STUFF HERE
}
// -------- IN THE CHILD FORM --------
Action<string> UpdateSettings = null;
// IN THE CHILD FORMS CONSTRUCTOR
public Options(Action<string> UpdateSettings)
{
InitializeComponent();
this.UpdateSettings = UpdateSettings;
}
private void btnUpdate_Click(object sender, EventArgs e)
{
// CALLING THE CALLBACK FUNCTION
if (UpdateSettings != null)
UpdateSettings("some data");
}
OpenForms Method
This method is easy (2 lines). But only works with forms that are open.
All you need to do is add these two lines where ever you want to pass some data.
Main frmMain = (Main)Application.OpenForms["Main"];
frmMain.UpdateSettings("Some data");
I provided my answer to a similar question here
You can use this;
Form1 button1 click
private void button1_Click(object sender, EventArgs e)
{
Form2 frm2 = new Form2();
this.Hide();
frm2.Show();
}
And add this to Form2
public string info = "";
Form2 button1 click
private void button1_Click(object sender, EventArgs e)
{
info = textBox1.Text;
this.Hide();
BeginInvoke(new MethodInvoker(() =>
{
Gogo();
}));
}
public void Gogo()
{
Form1 frm = new Form1();
frm.Show();
frm.Text = info;
}
if you change Modifiers Property of a control in a Form to Public, another Forms can access to that control.
f.e. :
Form2 frm;
private void Form1_Load(object sender, EventArgs e)
{
frm = new Form2();
frm.Show();
}
private void button1_Click(object sender, EventArgs e)
{
MessageBox.Show(frm.txtUserName.Text);
//txtUserName is a TextBox with Modifiers=Public
}
// In form 1
public static string Username = Me;
// In form 2's load block
string _UserName = Form1.Username;
the tag Properties receive object value
( C# send value to another form )
private void btn_Send_Click(object sender, EventArgs e)
{
Form frm = new formToSend();
frm.tag = obj;
frm.ShowDialog();
}
Receive value that sent from previous form ( frm )
Ex: sent data is string ( we need to type casting first, because tag value is an object )
public Receive_Form()
{
InitializeComponent();
MessageBox.Show((string)this.Tag);
}
How about using a public Event
I would do it like this.
public class Form2
{
public event Action<string> SomethingCompleted;
private void Submit_Click(object sender, EventArgs e)
{
SomethingCompleted?.Invoke(txtData.Text);
this.Close();
}
}
and call it from Form1 like this.
private void btnOpenForm2_Click(object sender, EventArgs e)
{
using (var frm = new Form2())
{
frm.SomethingCompleted += text => {
this.txtData.Text = text;
};
frm.ShowDialog();
}
}
Then, Form1 could get a text from Form2 when Form2 is closed
Thank you.

How can i change Form1.Text when its Opened with a button on Form2

I have 2 form and I want change Form1.Text when its run with a button on
Form2 !!!! I dont whant make a instance Form1.
Thanks friends**
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
Form2 F2 = new Form2();
F2.ShowDialog();
}
}
public partial class Form2 : Form
{
public Form2()
{
InitializeComponent();
}
private void ChangeForm1Text_Click(object sender, EventArgs e)
{
Form1
}
}
In this particular case (you need a reference to the Owner form) there is a simple shorcut that doesn't require to keep a local instance of the first form
Just pass the instance of Form1 as the Owner in the ShowDialog call
private void button1_Click(object sender, EventArgs e)
{
Form2 F2 = new Form2();
F2.ShowDialog(this);
}
Now you could reference the property Owner inside the Form2 code
private void ChangeForm1Text_Click(object sender, EventArgs e)
{
this.Owner.Text = "your new caption for form1";
}
One possible way for you to do this is to pass the instance of Form1 into a constructor on Form2`. So add this constructor and field to Form2:
private readonly Form1 _parentForm1;
public Form2(Form1 parentForm1) : this()
{
_parentForm1 = parentForm1;
}
Now when you create your Form2 in the button click, create it like this:
Form2 F2 = new Form2(this);
F2.ShowDialog();
Then you can use _parentForm1 anywhere in your instance of Form2 to refer back to the other form.

pass listbox item to a textbox on another form c#

I am making this simple Windows forms app in Visual studio in c#. I have two forms. On form1 I have a textbox,listbox and two buttons (one to insert into listbox from textbox and another to open form2). On form2 I only have a textbox. I just simply want, when click on a button (for opening form2) on form1, form2 to open and textbox to contain (on formLoad) selected item from listbox from form1. But when I click on button it says "Object reference not set to an instance of an object". What am I doing wrong? I am pretty sure it's something simple but I just can't get it.
Thanks in advance!
Here is my code:
on form1:
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void btnOpenForm2_Click(object sender, EventArgs e)
{
Form2 f2 = new Form2();
f2.ShowDialog();
}
private void button1_Click(object sender, EventArgs e)
{
listBox1.Items.Add(textBox1.Text);
}
public string Transfer
{
get { return listBox1.SelectedItem.ToString(); }
}
and on form2:
public partial class Form2 : Form
{
public Form2()
{
InitializeComponent();
}
private void Form2_Load(object sender, EventArgs e)
{
Form1 f1 = new Form1();
textBox1.Text = f1.Transfer;
}
Because in the Form2_Load event you always create a new instance of Form1 and then access the Transfer property which accesses listBox1.SelectedItem which is not set for the newly created form.
You should rather pass a referece to form 1 in the button event:
on form1:
private void btnOpenForm2_Click(object sender, EventArgs e)
{
Form2 f2 = new Form2(this);
f2.ShowDialog();
}
and on form2:
public partial class Form2 : Form
{
Form1 f1;
public Form2(Form1 f1)
{
this.f1 = f1;
InitializeComponent();
}
private void Form2_Load(object sender, EventArgs e)
{
textBox1.Text = this.f1.Transfer;
}
}
In your Form2_Load method, you're creating a new instance of the object Form1, separate from your existing item.
Instead, you need to either:
a) Pass a reference to your current Form1 object to Form2, so that Form2 can access the Transfer property.
or b) Add a new property to Form2 (called Transfer, say), and then when you create Form2, assign the current textbox value to this property, like so:
Form2 f2 = new Form2();
f2.Transfer = listBox1.SelectedItem.ToString();
f2.ShowDialog();
You could also do this by adding a parameter to the constructor of Form2, although that's really a design decision.
because you haven't selected your listbox item,value listBox1.SelectedItem is null.Practice doing try catch block
You are creating new Form1 instance here, which is not related to Form1 instance which you used to open Form2:
private void Form2_Load(object sender, EventArgs e)
{
Form1 f1 = new Form1(); // here is new instance of Form1 created
textBox1.Text = f1.Transfer;
}
So, this new Form1 instance does not have selected item and you have error. I suggest you to pass selected item value to Form2 when you opening Form2:
private void btnOpenForm2_Click(object sender, EventArgs e)
{
Form2 f2 = new Form2(Transfer); // pass selected item value to constructor
f2.ShowDialog();
}
All you need is changing Form2 constructor to accept this string:
public Form2(string transfer)
{
InitializeComponent();
textBox1.Text = transfer;
}

How to show another form after playing an SWF file in C#

I have a form that contains a Shockwave Flash object. I want that after playing the file or in the middle of it by pressing a key another form is shown. What should I do? Should I use an event?
Here's the code:
private void Form1_Load(object sender, EventArgs e)
{
axShockwaveFlash1.Movie = "c:/intro.swf";
axShockwaveFlash1.Forward();
axShockwaveFlash1.Play();
Form2 form2 = new Form2();
form2.Show();
}
And in Form2:
private void Form2_Load(object sender, EventArgs e)
{
Form1 form1 = new Form1();
form1.Close();
}
When I debug both forms are shown but I just want Form2.
You can pass the Form1 instance to the Form2 constructor, and close it there, like:
public Form2(Form1 form1)
{
InitializeComponents();
form1.Hide();//hide the control from the user, or close it if it not the main form..
}
Or if you want it to close the form1 instance when a button click then:
private Form1 _form1 = null;
public Form2(Form1 form1)
{
InitializeComponents();
_form1 = form1;
}
private void button1_Click(object sender, EventArgs e)
{
if (_form1 != null)
{
_form1.Hide();
}
}
Initialize the form2 in form1:
axShockwaveFlash1.Movie = "c:/intro.swf";
axShockwaveFlash1.Forward();
axShockwaveFlash1.Play();
Form2 form2 = new Form2(this);//"this here is the form1 instance itself"
form2.Show();
you can also use timer to check weather the movie is playing or not,if not then open new form which is form2
private void flash_Load(object sender, EventArgs e)
{
axShockwaveFlash1.Movie = #"C:\Users\Adil M\Documents\Visual Studio 2012\Projects\TProject\a.swf";
int a = axShockwaveFlash1.MovieData.Length;
timer1.Start();
}
now code on timer event
private void timer1_Tick(object sender, EventArgs e)
{
if (!axShockwaveFlash1.IsPlaying())
{
Fome2 fobj = new Form2();
this.Hide();
timer1.stop();
fobj.show();
}
else if(axShockwaveFlash1.IsPlaying())
{
}
}
this code is working for you only when your movie is complete or for any key you can also do it in timer
thanx

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