I have a Windows Forms App in C# with multiple UserControls.
In the UserControl1 I create panels dynamically, each panel containing multiple elements (checkbox, label listbox, picturebox, and multiple comboboxes). The values inside these elements differs between panels because I import the values from a Database. Also, I can add or remove elements from the listbox. Basically each panel is a presentation for a Pizza menu where you select the size (each size has its own price) and add or remove ingredients (from the listbox).
If you select one (or more) of the pizza's it is added in the UserControl2 (designated as a shopping cart). You can select multiple (different) pizza items from the UserControl1, and all of them will appear in the UserControl2 in the "shopping cart".
All these UserControls are contained in a panel in a Form and can be accessed by clicking a corresponding button.
My question is, how do I reload the UserControl1 from UserControl2?
Basically, after I'm done making an "order" (which can have multiple different items), I want to make a new "order" and I want the UserControl1 to look just like it was when I started the app.
I realize that I have to call the UserControl1_Load() method, but how do I do that from the UserControl2?
Or is there another method of "resetting" the UserControl1?
Obviously, I'm kind of new to C# so, please, have mercy on my soul.
Thank you very much in advance for your help!
I would implement an interface which each UserControl should implement to support this feature. The interface is a contract describing that the control has implemented a method. Just try to cast all usercontrols to that interface to support the restart functionality.
You should change it for your needs, but here is an example:
public interface ISupportInitialize
{
void Initialize();
}
public partial class MyUserControl : UserControl, ISupportInitialize
{
public MyUserControl()
{
// whatever you need to initialize
Initialize();
}
public void Initialize()
{
// remove old content if exists
// add new content
}
}
And in your main window:
public void ReInitializeControls()
{
// assume that panel1 contains the controls.
var userControlsWithInitialize = panel1.Controls.OfType<ISupportInitialize>();
foreach(var control in userControlsWithInitialize)
control.Initialize();
}
Calling the Load() method may not be sufficient. If you want a total reset behavior, you can remove the current control and add a brand new one in place of it.
Assuming you know how to implement an event handler, this goes inside the user control which triggers the reset operation, as a member variable:
public EventHandler OnOrderCompleted;
And when the order is completed, the control should invoke:
private void button1_Click(object sender, EventArgs e)
{
if (OnOrderCompleted != null)
{
OnOrderCompleted.Invoke(this, new EventArgs());
}
}
To keep coupling at minimum, this control should not directly know about the user control to be reset, but should inform any observers about the completion of an order. In our case, this can be the form hosting all the controls: (We name the triggering control orderControl here)
public Form2()
{
InitializeComponent();
orderControl.OnOrderCompleted += OnOrderCompleted;
}
private void OnOrderCompleted(object sender, EventArgs e)
{
Point currentLocation = productsControl.Location;
Controls.Remove(productsControl);
productsControl = new UserControl1();
productsControl.Location = currentLocation;
Controls.Add(productsControl);
}
Hope this helps.
Related
I am currently making an rpg using Winforms for a school project. However my knowledge on classes is so limited that I'm having trouble making a proper class that takes in data from 1 form, is used in the second form, then sent back to the first form.
The process I'm trying to accomplish is like this:
main form opens a second form that displays items in a listbox.
1
when you select an item and press a button to use it, the items effects are applied.
2
The data for the effect is in the first form where many other calculations are made with the same data.
3
I keep running into the problem of making a new object of a class and the data from the first form is reset. How would I go about either using an existing object from the first form, or creating a reference class maybe?
This is the function I want to run on the first form when the button on the second form is clicked.
public void SmallPot()
{
currentPHP += pHP * .25;
if (newPHP > pHP)
{
newPHP = pHP;
}
pHPBarUpdate = (int)(newPHP / pHP * 377);
pnlCurrentPHP.Width = pHPBarUpdate;
newPHP = currentPHP;
}
Expected:
When I click the use button on the popup form it closes and the items effects are displayed on the Main form.
What Happens:
Since I create a new object of form one in form two, all my variables are reset to 0 before the calculation, resulting in nothing happening after the second form closes.
I will give you a general guideline to implement a solution based on event definition and raising
Let's start from your second form where you need to communicate to the first form the event
public class Form2 : Form
{
// start creating the delegate type
public delegate void OnItemSelected(string itemName);
// declare the public event that this form will raise
public event OnItemSelected ItemSelected;
protected void cmdItemUse_Click(object sender, EventArgs e)
{
// When the user clicks to select an item....
string itemName = GetItemSelectedFromList();
// Check if someone is interested in this item selection
if(ItemSelected != null)
ItemSelected.Invoke(itemName);
}
}
Now we change something in the first Form. We need to create the second form and before displaying it we subscribe to the event exposed by the second form
public class Form1 : Form
{
... other stuff....
protected void cmdOpenSelection_Click(object sender, EventArgs e)
{
using(Form2 frm = new Form2())
{
// Subscribe the event giving it a method inside this class
// that doesn't return anything and receives a string
// as required by the delegate type of the event
frm.ItemSelected += handleItemSelection;
frm.ShowDialog(); // frm.Show();
}
}
private void handlerItemSelection(string itemName)
{
// This method is a custom Event handler and inside Form1
// will be called by Form2 through the Invoke on the event variable
}
}
In the example above I choose to pass a simple string, but of course you could pass anything including a reference type like an instance of a class containing all the info
required by the Item selection.
I have a button and hidden textbox on my main form. When I press the button it will hide the main form and show the second form. When I press the button on the second form I want to show the main form again but this time I need to show the hidden textbox. I know how to pass the text from a textbox to another form but not just the reference of the textbox.
You better pass the complete main form instance for the second form, and create a public function to set the textbox to visible, or create a property around it.
Something like:
//form1
Form2 second = new Form2(this);
}....
public void ShowTextBox()
{
textbox1.Visible=true;
}
//form2
Form parent;
public Form2(Form _parent)
{
parent=_parent;
}
///later
parent.Show();
parent.ShowTextBox();
Sounds to me like a custom event would be a better approach. Have the secondary form expose an event, which is raised at whatever appropriate time (your button press). In your main form, when you create your instance of your second form, subscribe to that event. Then run your "unhide" code from within the mainform's event subscription.
This keeps the coupling down on the two forms and results in much more easily maintainable and extensible code (for best effect, use interfaces, but events are a good middle ground for learning).
Something like this:
(it's been a long time since I worked with winforms, or events even, so if this needs refining let me know)
// your secondary/popup form's class
public partial class Form2 : Form
{
// add a custom event
public EventHandler<EventArgs> MyCustomEvent;
// link up your button click event
void InitializeComponent() {
myButton.Click += myButtonClick;
}
// when your button is clicked, raise your custom event
void myButtonClick(object sender, EventArgs, e) {
onMyCustomEvent();
}
// this "broadcasts" the event
void onMyCustomEvent() {
EventHandler<EventArgs> h = MyCustomEvent;
if (h != null) {
h(this, new EventArgs());
}
}
}
// your main form's class
public partial class MainForm
{
void InitializeComponent() {
// ...
}
void showForm2() {
var form2 = new Form2();
form2.MyCustomEvent += form2CustomEvent;
form2.Show();
}
void form2CustomEvent(object sender, EventArgs e) {
myHiddenTextBox.Visible = true;
}
}
All in all this is a much better approach in terms of code architecture. Now the popup doesn't care who opens it (it has no reference to the main form), and the custom event (which is really what you're after) can be managed to any level of control you need, without interfering how other thing work (for example, perhaps later you may want to have a different action that fires this same custom event...)
Food for thought.
Essentially I need the same thing that Form.ShowDialog() offers, but with a UserControl.
Inside a winform, I load a UserControl, which should allow a user to select an item from a list, and return it back to the caller.
For example:
var item = myUserControl.SelectItem();
Obviously, returning from a control's method is very simple. But how can I make it wait until user performs the required action with the control?
I can subscribe to an event of the control, but this path is not ideal.
Put simply, I want a UserControl's method to return after user clicks a specific button on it.
Simply put, a UserControl is really just a custom control and just like you drop a TextBox or a ListBox on your WinFrom, you drop your UserControl on the form.
Treat your UserControl just like you would treat any other control, like TextBox or ListBox.
So, just like you get the value from a TextBox through TextBox.Text or the SelectedValue or SelectedItem from a ListBox, you would call a method from your UserControl to return the SelectedItem.
Often times when the OK button is clicked or the form is closed is when in your code you would go through each of your form's controls getting their values. Presumably, you would do some validation to make sure proper values were entered, too.
Therefore, when your form is accepted is when you would call your UserControl's method to get the selected item. You don't have to subscribe to an event to wait for that to happen. Again, just treat it like you would treat a normal ListBox.
EDIT:
Knowing now more about the nature of your question this is my answer:
Say you have a UserControl that looks like this:
In the code behind you are going to have to set up an Event to monitor when the the OK button has been clicked inside the UserControl. This event will also notify a subscriber what the choice was that the user selected in your list:
public partial class SelectFromListUserControl : UserControl
{
public class SelectedItemEventArgs : EventArgs
{
public string SelectedChoice { get; set; }
}
public event EventHandler<SelectedItemEventArgs> ItemHasBeenSelected;
public SelectFromListUserControl()
{
InitializeComponent();
}
private void btnOK_Click(object sender, EventArgs e)
{
var handler = ItemHasBeenSelected;
if (handler != null)
{
handler(this, new SelectedItemEventArgs
{ SelectedChoice = listBox1.SelectedItem.ToString() });
}
}
}
On your main form you will have code patterned similar to the following.
There should be a routine to create or make visible this special user control.
It will hook the event in the user control so that the main form will be notified.
It will draw the user control.
The event handler will retrieve the value selected in the user control and then clear the user control and/or bring up another user control.
private void ShowSelectFromListWidget()
{
var uc = new SelectFromListUserControl();
uc.ItemHasBeenSelected += uc_ItemHasBeenSelected;
MakeUserControlPrimaryWindow(uc);
}
void uc_ItemHasBeenSelected(object sender,
SelectFromListUserControl.SelectedItemEventArgs e)
{
var value = e.SelectedChoice;
ClosePrimaryUserControl();
}
private void MakeUserControlPrimaryWindow(UserControl uc)
{
// my example just puts in in a panel, but for you
// put your special code here to handle your user control management
panel1.Controls.Add(uc);
}
private void ClosePrimaryUserControl()
{
// put your special code here to handle your user control management
panel1.Controls.Clear();
}
Embed it in a form and call the form modally (ShowDialog)?
But how can I make it wait until user performs the required action with the control?
The question is more about how to wait for the user to select item and click OK button without blocking entire user interface.
The answer is simple: Async/Await feature.
private readonly SelectCompletionSource as new TaskCompletionSource(of ResultType)
public async function SelectItemAsync() as ResultType
me.Visible = true
return await SelectComplectionSource.Task
end function
public function OK() as boolean
me.Visible = false
dim Result = me.SelectedItem
SelectComplectionSource.
SetResult(Result)
end function
To get an Item one calls
dim Item = await UserControl.SelectItemAsync
UserControl is shown to the user without blocking user interface. The selection task is started but paused until the result is ready.
By clicking OK button, user invokes OK function that queries selected item and makes selection task into completed state.
I am very new to C# programming. I come from autoit, and other scripting languages, the transition has been most difficult. Anyway I am working on a control in a windows form, basically I want it to be a LinkLabel control, that when you click it, it will become a textbox, once you enter your name, and either hit enter, or tab, it will set your name as the linklabel. But, I will have 10 of these controls on a form, and the way I have done it, it has taken three methods per control, so that is a lot of code, I'm sure I'm just doing it wrong, but here is what i have:
namespace Program
{
public partial class formMain : Form
{
public formMain()
{
InitializeComponent();
}
private void linkLabelPlayerName1_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
{
this.linkLabelPlayerName1.Hide();
this.textBoxPlayerName1.Show();
this.textBoxPlayerName1.Focus();
this.textBoxPlayerName1.KeyPress += new KeyPressEventHandler(textBoxPlayerName1_KeyPress);
this.textBoxPlayerName1.LostFocus += new EventHandler(textBoxPlayerName1_LostFocus);
}
private void textBoxPlayerName1_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == (char)Keys.Enter)
{
this.linkLabelPlayerName1.Text = this.textBoxPlayerName1.Text;
this.textBoxPlayerName1.Hide();
this.linkLabelPlayerName1.Show();
}
}
private void textBoxPlayerName1_LostFocus(object sender, EventArgs e)
{
this.linkLabelPlayerName1.Text = this.textBoxPlayerName1.Text;
this.textBoxPlayerName1.Hide();
this.linkLabelPlayerName1.Show();
}
}
}
I'm sure there is a way to use the last two methods between all 10 controls, so they don't have to be rewritten for each control. That is, textBoxPlayerName1_LostFocus() and textBoxPlayerName2_LostFocus().
Welcome to object orientated programming :).
You should created a derived class to encapsulate the functionality. For example:
class EditableText : UserControl
{
private LinkLabel lblName;
private TextBox txtName;
public EditableText()
{
// Construct objects, attach events and add them
// as children to this object
}
// Return the text of encapsulated TextBox
public string Text
{
get { return txtName.Text; }
}
}
Now you are able re-use this class in different areas, that's what object orientated programing all about!
Right-click on the windows forms application in the Solution Exporer, and select Add, then User Control...
Type in a name for the new control, like LinkLabelTextBox
This will give you a space to work in that looks like a Form, but without borders. This is your new control. Put your LinkLable and TextBox on this new control exactly as you put them in the window, and give them the functionality that you want. Then replace all your existing controls with instances of this new control. You will create 10 of these, instead of creating ten LinkLabels and ten TextBoxes. And all of the functionality that you want will be built-in to your new control, so that code does not need to be repeated.
Instead of a linkLabelPlayerName1 and textBoxPlayerName1, you will have a linkLabelTextBoxPlayerName1, and none of the Show, Hide, Focus stuff will clutter your form code.
Also, be sure to include a public Text property so you can get the value that the user typed out of this control.
Create your own Control with the functionality.
Your code is correct.
To make it cleaner, you should move it to a separate UserControl, and set the Text property to the textbox's value.
I'm using the DockPanel Suite in my winforms app. The DockContent class is derived from System.Windows.Forms.Form class and my two forms, dockRounds and dockToolbox, inherit from the DockContent class.
This is the first time I've done this and this is probably a stupid question, but in runtime, how do I access the controls of the dockRounds and dockToolbox forms?
Here is how I load the two forms when the app first runs:
public partial class frmMainNew : Form
clsMWDockPanel mapPanel;
dockToolbox dockT = new dockToolbox();
dockRounds dockR = new dockRounds();
public frmMainNew()
{
InitializeComponent();
dockPanel = new DockPanel();
SuspendLayout();
dockPanel.Parent = panelMain;
dockPanel.Dock = DockStyle.Fill;
dockPanel.DefaultFloatWindowSize = new Size(108, 528);
dockPanel.BringToFront();
dockPanel.BackColor = Color.Transparent;
dockPanel.DocumentStyle = DocumentStyle.DockingSdi;
ResumeLayout();
string error = "Errors:\r\n";
try
{
loadRounds();
loadToolbox();
}
catch (Exception)
{
error = error + "The Toolbox and/or Rounds menu could not be created\r\n";
}
}
public void loadToolbox()
{
dockT.CloseButton = false;
dockT.ShowHint = DockState.Float;
dockT.Text = "Toolbox";
dockT.BackColor = Color.WhiteSmoke;
dockT.Icon = this.Icon;
dockT.Show(dockPanel);
}
public void loadRounds()
{
if (mapPanel == null)
{
CreateMapPanel().Show(dockPanel, DockState.Document);
}
mapMain.Anchor = AnchorStyles.Top | AnchorStyles.Bottom | AnchorStyles.Left | AnchorStyles.Right;
//mapMain.BringToFront();
dockR.CloseButton = false;
dockR.ShowHint = DockState.DockRightAutoHide;
dockR.Text = "Rounds Menu";
dockR.BackColor = Color.WhiteSmoke;
dockR.Icon = this.Icon;
dockR.Show(dockPanel);
}
DockContent CreateMapPanel()
{
mapPanel = new clsMWDockPanel();
mapPanel.ShowHint = DockState.Document;
mapPanel.Controls.Add(mapMain);
return mapPanel;
}
Many thanks in advance
leddy
There are several strategies you can use to achieve communication/linkage between objects on different Forms. Note : My reply here is not going to address any issues specifically related to DockPanelSuite, and is not going to consider the difference between the "secondary" forms being "independent" (i.e., they are not "owned" by the MainForm) or being made child Forms of the MainForm. This is a conscious choice made on the basis of believing that what you are asking about is independent of those possible variations in implementation.
the simplest strategy (if tedious for a lot of controls) is to declare Public Properties in your secondary Forms that expose the controls you want to manipulate from your Main Form. For example, let's say Form2 has a button, and you want to handle its click event on your main form :
In Form2 define a property like :
public Button form2Button
{
get { return button1; }
}
Now in the Load event of your Main Form, assuming that's where an instance of Form2 is created, you can subscribe to the Click event of the Button on Form2 :
Form2 myForm2;
Form3 myForm3;
private void Form1_Load(object sender, EventArgs e)
{
myForm2 = new Form2();
myForm2.form2Button.Click += new EventHandler(form2Button_Click);
myForm3 = new Form3();
}
And you can easily imagine that in Form3 you have a TextBox that you have exposed with a Public Property in the same way you exposed the Button on Form2.
So you can implement the MainForm's event handler like this for the Button click on Form2 :
public void form2Button_Click(object sender, EventArgs e)
{
// do something here with the TextBox on Form3
// myForm3.theTextBox.Text =
}
... other strategies ...
in your secondary form, for example, a button press can raise a Public Event which the Main Form (or any other entity to which Form2 is exposed) could subscribe to and then dispatch the appropriate whatever to the appropriate target.
you can abstract message-passing in general at a higher level into a single (perhaps static) class where publishers send messages, and the messages are dispatched to registered listeners.
Finally, the discussion here may be of interest to you :
Using The Controls Of One Form Into Another
best,
Your classes, dockRounds and dockToolbox should expose any properties/events that you want to access. So if you want to hook up to a control's event, route it to a public event.
You can set the access modifier on a control to make it as accessible as you like. The default is "Private" which is why you can't access the controls from the main form.
In Visual Studio, on the Properties tab, there is a Modifiers property which sets the access modifier that is used in the generated designer file.
Set this to "Public" and you be able to access the control from the main form.
I've just used this when I inherited one form from another. By setting the modifier to "Protected" (or "Protected Internal") I was able to access the controls defined in the base class.
Have you tried accessing the Controls property?
var controls = dockRounds.Controls;