I would like to retrieve all components which are part of a Form's or UserControl's components collection.
The components collection is added by VS winforms designer. The components variable is private and the problem is how to retrieve all components from all descendants. I would like to have a method which returns list of components throught the type hierarchy. For example let's say I have MyForm (descendant of BaseForm) and BaseForm (descendant of Form). I would like to put method "GetComponents" which returns components of both MyForm and BaseForm.
Do you suggest any other option than using the reflection?
Some time ago I have implemented the solution in which I created custom base form and control implementations, adding one property and overriding the OnLoad method:
public partial class FormBase : Form
{
public FormBase ()
{
this.InitializeComponent();
}
protected ConsistencyManager ConsistencyManager { get; private set; }
protected override void OnLoad(System.EventArgs e)
{
base.OnLoad(e);
if (this.ConsistencyManager == null)
{
this.ConsistencyManager = new ConsistencyManager(this);
this.ConsistencyManager.MakeConsistent();
}
}
}
The ConsistencyManager class finds all controls, components and also supports search of custom child controls within specific control. Copy/paste of code from MakeConsistent method:
public void MakeConsistent()
{
if (this.components == null)
{
List<IComponent> additionalComponents = new List<IComponent>();
// get all controls, including the current one
this.components =
this.GetAllControls(this.parentControl)
.Concat(GetAllComponents(this.parentControl))
.Concat(new Control[] { this.parentControl });
// now find additional components, which are not present neither in Controls collection nor in components
foreach (var component in this.components)
{
IAdditionalComponentsProvider provider = GetAdditinalComponentsProvider(component.GetType().FullName);
if (provider != null)
{
additionalComponents.AddRange(provider.GetChildComponents(component));
}
}
if (additionalComponents.Count > 0)
{
this.components = this.components.Concat(additionalComponents);
}
}
this.MakeConsistent(this.components);
}
If anyone would like full sample or source let me know.
Best regards,
Zvonko
PS: In the same manner I have also created the performance counter that counts number of invocations on main thread.
Related
How do I get access to the parent controls of user control in C# (winform). I am using the following code but it is not applicable on all types controls such as ListBox.
Control[] Co = this.TopLevelControl.Controls.Find("label7", true);
Co[0].Text = "HelloText"
Actually, I have to add items in Listbox placed on parent 'Form' from a user control.
Description
You can get the parent control using Control.Parent.
Sample
So if you have a Control placed on a form this.Parent would be your Form.
Within your Control you can do
Form parentForm = (this.Parent as Form);
More Information
MSDN: Control.Parent Property
Update after a comment by Farid-ur-Rahman (He was asking the question)
My Control and a listbox (listBox1) both are place on a Form (Form1). I have to add item in a listBox1 when user press a button placed in my Control.
You have two possible ways to get this done.
1. Use `Control.Parent
Sample
MyUserControl
private void button1_Click(object sender, EventArgs e)
{
if (this.Parent == null || this.Parent.GetType() != typeof(MyForm))
return;
ListBox listBox = (this.Parent as MyForm).Controls["listBox1"] as ListBox;
listBox.Items.Add("Test");
}
or
2.
put a property public MyForm ParentForm { get; set; } to your UserControl
set the property in your Form
assuming your ListBox is named listBox1 otherwise change the name
Sample
MyForm
public partial class MyForm : Form
{
public MyForm()
{
InitializeComponent();
this.myUserControl1.ParentForm = this;
}
}
MyUserControl
public partial class MyUserControl : UserControl
{
public MyForm ParentForm { get; set; }
public MyUserControl()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
if (ParentForm == null)
return;
ListBox listBox = (ParentForm.Controls["listBox1"] as ListBox);
listBox.Items.Add("Test");
}
}
You can use Control.Parent to get the parent of the control or Control.FindForm to get the first parent Form the control is on. There is a difference between the two in terms of finding forms, so one may be more suitable to use than the other.:
The control's Parent property value might not be the same as the Form
returned by FindForm method. For example, if a RadioButton control is
contained within a GroupBox control, and the GroupBox is on a Form,
the RadioButton control's Parent is the GroupBox and the GroupBox
control's Parent is the Form.
Control has a property called Parent, which will give the parent control. http://msdn.microsoft.com/en-us/library/system.windows.forms.control.parent.aspx
eg Control p = this.Parent;
You can get the Parent of a control via
myControl.Parent
See MSDN:
Control.Parent
A generic way to get a parent of a control that I have used is:
public static T GetParentOfType<T>(this Control control)
{
const int loopLimit = 100; // could have outside method
var current = control;
var i = 0;
do
{
current = current.Parent;
if (current == null) throw new Exception("Could not find parent of specified type");
if (i++ > loopLimit) throw new Exception("Exceeded loop limit");
} while (current.GetType() != typeof(T));
return (T)Convert.ChangeType(current, typeof(T));
}
It needs a bit of work (e.g. returning null if not found or error) ... but hopefully could help someone.
Usage:
var parent = currentControl.GetParentOfType<TypeWanted>();
Enjoy!
According to Ruskins answer and the comments here I came up with the following (recursive) solution:
public static T GetParentOfType<T>(this Control control) where T : class
{
if (control?.Parent == null)
return null;
if (control.Parent is T parent)
return parent;
return GetParentOfType<T>(control.Parent);
}
Not Ideal, but try this...
Change the usercontrol to Component class (In the code editor), build the solution and remove all the code with errors (Related to usercontrols but not available in components so the debugger complains about it)
Change the usercontrol back to usercontrol class...
Now it recognises the name and parent property but shows the component as non-visual as it is no longer designable.
((frmMain)this.Owner).MyListControl.Items.Add("abc");
Make sure to provide access level you want at Modifiers properties other than Private for MyListControl at frmMain
If you want to get any parent by any child control you can use this code,
and when you find the UserControl/Form/Panel or others you can call funnctions or set/get values:
Control myControl= this;
while (myControl.Parent != null)
{
if (myControl.Parent!=null)
{
myControl = myControl.Parent;
if (myControl.Name== "MyCustomUserControl")
{
((MyCustomUserControl)myControl).lblTitle.Text = "FOUND IT";
}
}
}
I have a fairly simple class structure where there are Graphic objects, each contains a List<Symbol> and each Symbol contains a List<Alias>: amgonst their other properties.
The obvious way (and my current method) is to use nested foreach loops to generate the nodes and to populate the tree view (this actually works fine) like below:
public void ToTree(TreeView treeControl)
{
treeControl.Nodes.Clear();
List<TreeNode> graphicsNodes = new List<TreeNode>();
foreach (Graphic graphic in Graphics)
{
List<TreeNode> symbolNodes = new List<TreeNode>();
foreach (Symbol symbol in graphic.Symbols)
{
List<TreeNode> aliasNodes = new List<TreeNode>();
foreach (Alias alias in symbol.Aliases)
{
aliasNodes.Add(new TreeNode(alias.AliasName + ": " + alias.AliasValue));
}
symbolNodes.Add(new TreeNode(symbol.SymbolName, aliasNodes.ToArray()));
}
graphicsNodes.Add(new TreeNode(graphic.FileName, symbolNodes.ToArray()));
}
treeControl.Nodes.AddRange(graphicsNodes.ToArray());
}
However, I'm curious if there is anything that I can implement in my class, or any methods that I can overload so that I can simply do something similar to treeView.Nodes.Add(graphic).
Ideally, this would allow for me to determine which object is being clicked on with the NodeClickEvent rather than me having to take the node's text and then perform a search separately.
This is so that I would have direct access to the fields and members of each object from within that node, making it much easier to modify properties from the TreeView click events.
What you can do is create subclasses of TreeNode that accept your classes in their constructor. You can then have each subclass implement the specific handling for that type. I looked into the suggestion from Hans to do something useful with the TreeNodeCollection but this class has no public constructor so I couldn't figure out how that should work.
A simple implementation looks like this for your three classes I distilled from your example:
Graphic and GraphicNode
public class GraphicNode:TreeNode
{
// takes a Graphic instance
public GraphicNode(Graphic grp)
{
// how do you want to represent it
this.Text = grp.FileName;
// and this class 'knows' how to handle its children
Nodes.AddRange(grp.Symbols.Select(s => new SymbolNode(s)).ToArray());
}
}
Symbol and SymbolNode
public class SymbolNode:TreeNode
{
public SymbolNode(Symbol sym)
{
this.Text = sym.SymbolName;
Nodes.AddRange(sym.Aliases.Select(ali => new AliasesNode(ali)).ToArray());
}
}
Alias and AliasNode
Notice how this class implements a public Click method. You can leverage that from an NodeMouseClick event.
public class AliasesNode:TreeNode
{
public AliasesNode(Aliases al)
{
this.Text = String.Format("{0} - {1}", al.AliasName, al.AliasValue);
}
public void Click()
{
MessageBox.Show(new String(this.Text.Reverse().ToArray()));
}
}
Populate the Treeview
The following code populates the Treeview by adding the GraphicNodes. By callimg BeginUpdate first, we prevent that the control draws its content on every node that is added. Don't forget to call EndUpdate so the control layouts and redraws all newly added nodes. Notice that you only need to add the GraphicNodes here, the adding of the other nodes is handled by the subclassed TreeNodes.
// tell the control to hold its paint/redraw events until
// we're done adding all items
tv.BeginUpdate();
foreach(var g in graphics)
{
tv.Nodes.Add(new GraphicNode(g));
}
// done, draw all nodes now
tv.EndUpdate();
If you wire up the NodeMouseClick to the following event handler you can reach into the specific implementation of the TreeNode:
private void treeView1_NodeMouseClick(object sender, TreeNodeMouseClickEventArgs e)
{
var node = e.Node as AliasesNode;
if (node != null)
{
node.Click();
}
}
When we click an AliasTreenode we should see the MessageBox popup that is implemented in the Click method of that class:
I've created simple custom control - derived from Component class:
public partial class TrialChecker : Component
{
private int _trialDays;
public int TrialDays
{
get { return _trialDays; }
set { _trialDays = value;}
}
public TrialChecker()
{
InitializeComponent();
MessageBox.Show(TrialDays.ToString());
}
public int GetTrialDays()
{
return _trialDays;
}
}
This control will be used to implement trial functionality in my application. Application (before it starts) should check trial remaining days and display notify dialog containing trial remaining days and textbox to write unlock key.
But I want to minimalise amount of code needed to wirte while using this control. So, my idea is to place trial check code inside my control and - just after control is created, it should display remaining days.
Trial period (TrialDays property) is set on user designer and it should be available to use just afeter control is created. As you can see, I tried to put this to constructor but it does not work, because constructor is called before setting TrialDays to valuje entered in user designer. And MessageBox always displays default value 0.
There is no any OnLoad or OnCreate events abailable to override. So, how can I automatically check trial status using value entered in designer?
The Component class is very simple, it just provides a way to host the component on a form at design time, giving access to its properties with the Properties window. But it has no notable useful events, using a component requires explicit code in the form. Like OpenFormDialog, nothing happens with it until you call its ShowDialog() method.
The constructor is usable but unfortunately it runs too early. The DesignMode property tells you whether or not a component runs at design time but it isn't set yet at constructor time. You'll need to delay the code and that's difficult because there are no other methods or events that run later.
A solution is to use the events of the form that you dropped the component on. Like the Load event. That requires some giddy code to coax the designer to tell you about the form. That technique is used by the ErrorProvider component, it requires exposing a property of type ContainerControl and overriding the Site property setter. Like this:
using System;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Windows.Forms;
public partial class Component1 : Component {
private ContainerControl parent;
[Browsable(false)]
public ContainerControl ContainerControl {
get { return parent; }
set {
if (parent == null) {
var form = value.FindForm();
if (form != null) form.Load += new EventHandler(form_Load);
}
parent = value;
}
}
public override ISite Site {
set {
// Runs at design time, ensures designer initializes ContainerControl
base.Site = value;
if (value == null) return;
IDesignerHost service = value.GetService(typeof(IDesignerHost)) as IDesignerHost;
if (service == null) return;
IComponent rootComponent = service.RootComponent;
this.ContainerControl = rootComponent as ContainerControl;
}
}
void form_Load(object sender, EventArgs e) {
if (!this.DesignMode) {
MessageBox.Show("Trial");
}
}
}
The code is inscrutable, but you can be pretty sure it is reliable and stable because this is what the ErrorProvider component uses. Be sure to call Environment.Exit() when the trial period has ended, an exception isn't going to work well.
I have a Panel I want to fill with some UserControl(s) at runtime. These controls are complex and may be interdependent, so I'd like them:
to be editable with Visual Studio designer;
to be in the same context (= defined in the same class);
Both of the requirements are a must-have.
Considering UserControl is itself an indexed collection of Control(s), I started designing my controls in the same class, without caring about real positioning of them (that will be specified runtime). I already used the same identical approach with DevComponents ribbon containers (with much satisfaction), so I initially thought the same was possible with standard UserControl(s).
I eventually realized that a Control can be inside only one Control.ControlCollection instance at a time, so I couldn't use the Controls property and add controls to another panel without removing them from the original "dummy" UserControl.
My question is: is there a clean and supported way to create this designer-aware UserControl collection? I would call this approach a pattern because it really adds code clearness and efficiency.
Thanks,
Francesco
P.S.: as a workaround, I created a DummyControlContainer class that inherits UserControl and keeps a Dictionary map filled at ControlAdded event (code follows). Wondering if there's something cleaner.
public partial class DummyControlContainer : UserControl
{
private Dictionary<string, Control> _ControlMap;
public DummyControlContainer()
{
InitializeComponent();
_ControlMap = new Dictionary<string, Control>();
this.ControlAdded += new ControlEventHandler(DummyControlCollection_ControlAdded);
}
void DummyControlCollection_ControlAdded(object sender, ControlEventArgs args)
{
_ControlMap.Add(args.Control.Name, args.Control);
}
public Control this[string name]
{
get { return _ControlMap[name]; }
}
}
After testing and using it in a real world project, I'm more and more convinced that my solution was clean and safe if you need such a pattern. This container is intended to be filled with controls such as panels or similar. To prevent some bad behaviors with bindable data sources, I provided each new control added to this container with its own BindingContext. Enjoy.
public partial class DummyControlContainer : UserControl
{
private Dictionary<string, Control> _ControlMap;
public DummyControlContainer()
{
InitializeComponent();
_ControlMap = new Dictionary<string, Control>();
this.ControlAdded +=
new ControlEventHandler(DummyControlCollection_ControlAdded);
}
void DummyControlCollection_ControlAdded(object sender,
ControlEventArgs args)
{
// If the added Control doesn't provide its own BindingContext,
// set a new one
if (args.Control.BindingContext == this.BindingContext)
args.Control.BindingContext = new BindingContext();
_ControlMap.Add(args.Control.Name, args.Control);
}
public Control this[string name]
{
get { return _ControlMap[name]; }
}
}
I have a non-visual component which manages other visual controls.
I need to have a reference to the form that the component is operating on, but i don't know how to get it.
I am unsure of adding a constructor with the parent specified as control, as i want the component to work by just being dropped into the designer.
The other thought i had was to have a Property of parent as a control, with the default value as 'Me'
any suggestions would be great
Edit:
To clarify, this is a component, not a control, see here :ComponentModel.Component
[It is important to understand that the ISite technique below only works at design time. Because ContainerControl is public and gets assigned a value VisualStudio will write initialization code that sets it at run-time. Site is set at run-time, but you can't get ContainerControl from it]
Here's an article that describes how to do it for a non-visual component.
Basically you need to add a property ContainerControl to your component:
public ContainerControl ContainerControl
{
get { return _containerControl; }
set { _containerControl = value; }
}
private ContainerControl _containerControl = null;
and override the Site property:
public override ISite Site
{
get { return base.Site; }
set
{
base.Site = value;
if (value == null)
{
return;
}
IDesignerHost host = value.GetService(
typeof(IDesignerHost)) as IDesignerHost;
if (host != null)
{
IComponent componentHost = host.RootComponent;
if (componentHost is ContainerControl)
{
ContainerControl = componentHost as ContainerControl;
}
}
}
}
If you do this, the ContainerControl will be initialized to reference the containing form by the designer. The linked article explains it in more detail.
A good way to see how to do things is to look at the implementation of Types in the .NET Framework that have behaviour similar to what you want with a tool such as Lutz Reflector. In this case, System.Windows.Forms.ErrorProvider is a good example to look at: a Component that needs to know its containing Form.
I use a recursive call to walk up the control chain. Add this to your control.
public Form ParentForm
{
get { return GetParentForm( this.Parent ); }
}
private Form GetParentForm( Control parent )
{
Form form = parent as Form;
if ( form != null )
{
return form;
}
if ( parent != null )
{
// Walk up the control hierarchy
return GetParentForm( parent.Parent );
}
return null; // Control is not on a Form
}
Edit: I see you modified your question as I was typing this. If it is a component, the constructor of that component should take it's parent as a parameter and the parent should pass in this when constructed. Several other components do this such as the timer.
Save the parent control as a member and then use it in the ParentForm property I gave you above instead of this.
You will have to set the parent container some how. Your component is just a class, that resides in memory just like everything else. It has no true context of what created it unless something tells you that it did. Create a Parent control property and set it.
Or simply derive from control and use FindForm(). Not all controls must have a visible component
If the componenet is managing other visual controls, then you should be able to get to the parent through them.
I found this solution which does not need the input. For C# I implemented it this way:
public partial class RegistryManager : Component, ISupportInitialize
{
private Form _parentForm;
public Form ParentForm
{
get { return _parentForm; }
set { _parentForm = value; }
}
// Etc....
#region ISupportInitialize
public void BeginInit() { }
public void EndInit()
{
setUpParentForm();
}
private void setUpParentForm()
{
if (_parentForm != null) return; // do nothing if it is set
IDesignerHost host;
if (Site != null)
{
host = Site.GetService(typeof(IDesignerHost)) as IDesignerHost;
if (host != null)
{
if (host.RootComponent is Form)
{
_parentForm = (Form)host.RootComponent;
}
}
}
}
#endregion
}
This way allows the set ParentForm by user, but it is set by parent form as Default.
I hope it helps you.
Try This ....
private Form GetParentForm(Control parent)
{
if (parent is Form)
return parent as Form;
return parent.FindForm();
}
Call GetParentForm(this.Parent) from component
I think you want to use the Site property of the IComponent. It's more or less an equivalent to the Parent property.
Thanks Rob, I used your solution in a VB.Net program, looks like this:
''' <summary>
''' Returns the parent System.Windows.form of the control
''' </summary>
''' <param name="parent"></param>
''' <returns>First parent form or null if no parent found</returns>
''' <remarks></remarks>
Public Shared Function GetParentForm(ByVal parent As Control) As Form
Dim form As Form = TryCast(parent, Form)
If form IsNot Nothing Then
Return form
End If
If parent IsNot Nothing Then
' Walk up the control hierarchy
Return GetParentForm(parent.Parent)
End If
' Control is not on a Form
Return Nothing
End Function
Referenced it on my blog:
http://www.dailycode.info/Blog/post/2012/07/03/How-to-get-a-user-controls-parent-form-(Windows-forms).aspx
If the component related Form is the active Form you may get it by Form.ActiveForm.
A improvement of above is:
public static Form ParentForm(this Control ctrl) => ctrl as Form ?? ctrl.FindForm();