I need to get all controls on a form that are of type x. I'm pretty sure I saw that code once in the past that used something like this:
dim ctrls() as Control
ctrls = Me.Controls(GetType(TextBox))
I know I can iterate over all controls getting children using a recursive function, but is there something easier or more straightforward, maybe like the following?
Dim Ctrls = From ctrl In Me.Controls Where ctrl.GetType Is Textbox
I modified from @PsychoCoder. All controls could be found now (include nested).
public static IEnumerable<T> GetChildrens<T>(Control control)
{
var type = typeof (T);
var allControls = GetAllChildrens(control);
return allControls.Where(c => c.GetType() == type).Cast<T>();
}
private static IEnumerable<Control> GetAllChildrens(Control control)
{
var controls = control.Controls.Cast<Control>();
return controls.SelectMany(c => GetAllChildrens(c))
.Concat(controls);
}
public static IEnumerable<T> GetAllControls<T>(this Control control) where T : Control
{
foreach (Control c in control.Controls)
{
if (c is T)
yield return (T)c;
foreach (T c1 in c.GetAllControls<T>())
yield return c1;
}
}
In C# (since you tagged it as such) you could use a LINQ expression like this:
List<Control> c = Controls.OfType<TextBox>().Cast<Control>().ToList();
Edit for recursion:
In this example, you first create the list of controls and then call a method to populate it. Since the method is recursive, it doesn't return the list, it just updates it.
List<Control> ControlList = new List<Control>();
private void GetAllControls(Control container)
{
foreach (Control c in container.Controls)
{
GetAllControls(c);
if (c is TextBox) ControlList.Add(c);
}
}
It may be possible to do this in one LINQ statement using the Descendants function, though I am not as familiar with it. See this page for more information on that.
Edit 2 to return a collection:
As @ProfK suggested, a method that simply returns the desired controls is probably better practice. To illustrate this I have modified the code as follows:
private IEnumerable<Control> GetAllTextBoxControls(Control container)
{
List<Control> controlList = new List<Control>();
foreach (Control c in container.Controls)
{
controlList.AddRange(GetAllTextBoxControls(c));
if (c is TextBox)
controlList.Add(c);
}
return controlList;
}
You can try this if you want :)
private void ClearControls(Control.ControlCollection c)
{
foreach (Control control in c)
{
if (control.HasChildren)
{
ClearControls(control.Controls);
}
else
{
if (control is TextBox)
{
TextBox txt = (TextBox)control;
txt.Clear();
}
if (control is ComboBox)
{
ComboBox cmb = (ComboBox)control;
if (cmb.Items.Count > 0)
cmb.SelectedIndex = -1;
}
if (control is CheckBox)
{
CheckBox chk = (CheckBox)control;
chk.Checked = false;
}
if (control is RadioButton)
{
RadioButton rdo = (RadioButton)control;
rdo.Checked = false;
}
if (control is ListBox)
{
ListBox listBox = (ListBox)control;
listBox.ClearSelected();
}
}
}
}
private void btnClear_Click(object sender, EventArgs e)
{
ClearControls((ControlCollection)this.Controls);
}
Using reflection:
// Return a list with all the private fields with the same type
List<T> GetAllControlsWithTypeFromControl<T>(Control parentControl)
{
List<T> retValue = new List<T>();
System.Reflection.FieldInfo[] fields = parentControl.GetType().GetFields(System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
foreach (System.Reflection.FieldInfo field in fields)
{
if (field.FieldType == typeof(T))
retValue.Add((T)field.GetValue(parentControl));
}
}
List<TextBox> ctrls = GetAllControlsWithTypeFromControl<TextBox>(this);
Simply:
For Each ctrl In Me.Controls.OfType(Of Button)()
ctrl.Text = "Hello World!"
Next
You can use a LINQ query to do this. This will query everything on the form that is type TextBox
var c = from controls in this.Controls.OfType<TextBox>()
select controls;
IEnumerable<Control> Ctrls = from Control ctrl in Me.Controls where ctrl is TextBox | ctrl is GroupBox select ctr;
Lambda Expressions
IEnumerable<Control> Ctrls = Me.Controls.Cast<Control>().Where(c => c is Button | c is GroupBox);
This is an improved version of the recursive GetAllControls() that actually works on private vars:
private void Test()
{
List<Control> allTextboxes = GetAllControls(this);
}
private List<Control> GetAllControls(Control container, List<Control> list)
{
foreach (Control c in container.Controls)
{
if (c is TextBox) list.Add(c);
if (c.Controls.Count > 0)
list = GetAllControls(c, list);
}
return list;
}
private List<Control> GetAllControls(Control container)
{
return GetAllControls(container, new List<Control>());
}
A clean and easy solution (C#):
static class Utilities {
public static List<T> GetAllControls<T>(this Control container) where T : Control {
List<T> controls = new List<T>();
if (container.Controls.Count > 0) {
controls.AddRange(container.Controls.OfType<T>());
foreach (Control c in container.Controls) {
controls.AddRange(c.GetAllControls<T>());
}
}
return controls;
}
}
Get all textboxes:
List<TextBox> textboxes = myControl.GetAllControls<TextBox>();
Here is my Extension method. It's very efficient and it's lazy.
Usage:
var checkBoxes = tableLayoutPanel1.FindChildControlsOfType<CheckBox>();
foreach (var checkBox in checkBoxes)
{
checkBox.Checked = false;
}
The code is:
public static IEnumerable<TControl> FindChildControlsOfType<TControl>(this Control control) where TControl : Control
{
foreach (var childControl in control.Controls.Cast<Control>())
{
if (childControl.GetType() == typeof(TControl))
{
yield return (TControl)childControl;
}
else
{
foreach (var next in FindChildControlsOfType<TControl>(childControl))
{
yield return next;
}
}
}
}
This may work:
Public Function getControls(Of T)() As List(Of T)
Dim st As New Stack(Of Control)
Dim ctl As Control
Dim li As New List(Of T)
st.Push(Me)
While st.Count > 0
ctl = st.Pop
For Each c In ctl.Controls
st.Push(CType(c, Control))
If c.GetType Is GetType(T) Then
li.Add(CType(c, T))
End If
Next
End While
Return li
End Function
I think the function to get all controls you are talking about is only available to WPF.
Here is the Solution.
https://stackoverflow.com/a/19224936/1147352
I have written this piece of code and selected only the panels, you can add more switches or ifs. in it
It might be the ancient technique, but it works like charm. I used recursion to change the color of all labels of the control. It works great.
internal static void changeControlColour(Control f, Color color)
{
foreach (Control c in f.Controls)
{
// MessageBox.Show(c.GetType().ToString());
if (c.HasChildren)
{
changeControlColour(c, color);
}
else
if (c is Label)
{
Label lll = (Label)c;
lll.ForeColor = color;
}
}
}
public List<Control> GetAllChildControls(Control Root, Type FilterType = null)
{
List<Control> AllChilds = new List<Control>();
foreach (Control ctl in Root.Controls) {
if (FilterType != null) {
if (ctl.GetType == FilterType) {
AllChilds.Add(ctl);
}
} else {
AllChilds.Add(ctl);
}
if (ctl.HasChildren) {
GetAllChildControls(ctl, FilterType);
}
}
return AllChilds;
}
For anyone looking for a VB version of Adam's C# code written as an extension of the Control class:
''' <summary>Collects child controls of the specified type or base type within the passed control.</summary>
''' <typeparam name="T">The type of child controls to include. Restricted to objects of type Control.</typeparam>
''' <param name="Parent">Required. The parent form control.</param>
''' <returns>An object of type IEnumerable(Of T) containing the control collection.</returns>
''' <remarks>This method recursively calls itself passing child controls as the parent control.</remarks>
<Extension()>
Public Function [GetControls](Of T As Control)(
ByVal Parent As Control) As IEnumerable(Of T)
Dim oControls As IEnumerable(Of Control) = Parent.Controls.Cast(Of Control)()
Return oControls.SelectMany(Function(c) GetControls(Of T)(c)).Concat(oControls.Where(Function(c) c.GetType() Is GetType(T) Or c.GetType().BaseType Is GetType(T))
End Function
NOTE: I've added BaseType matching for any derived custom controls. You can remove this or even make it an optional parameter if you wish.
Usage
Dim oButtons As IEnumerable(Of Button) = Me.GetControls(Of Button)()
public IEnumerable<T> GetAll<T>(Control control) where T : Control
{
var type = typeof(T);
var controls = control.Controls.Cast<Control>().ToArray();
foreach (var c in controls.SelectMany(GetAll<T>).Concat(controls))
if (c.GetType() == type) yield return (T)c;
}
Don't forget that you can also have a TextBox within other controls other than container controls too. You can even add a TextBox to a PictureBox.
So you also need to check if
someControl.HasChildren = True
in any recursive function.
This is the result I had from a layout to test this code:
TextBox13 Parent = Panel5
TextBox12 Parent = Panel5
TextBox9 Parent = Panel2
TextBox8 Parent = Panel2
TextBox16 Parent = Panel6
TextBox15 Parent = Panel6
TextBox14 Parent = Panel6
TextBox10 Parent = Panel3
TextBox11 Parent = Panel4
TextBox7 Parent = Panel1
TextBox6 Parent = Panel1
TextBox5 Parent = Panel1
TextBox4 Parent = Form1
TextBox3 Parent = Form1
TextBox2 Parent = Form1
TextBox1 Parent = Form1
tbTest Parent = myPicBox
Try this with one Button and one RichTextBox on a form.
Option Strict On
Option Explicit On
Option Infer Off
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim pb As New PictureBox
pb.Name = "myPicBox"
pb.BackColor = Color.Goldenrod
pb.Size = New Size(100, 100)
pb.Location = New Point(0, 0)
Dim tb As New TextBox
tb.Name = "tbTest"
pb.Controls.Add(tb)
Me.Controls.Add(pb)
Dim textBoxList As New List(Of Control)
textBoxList = GetAllControls(Of TextBox)(Me)
Dim sb As New System.Text.StringBuilder
For index As Integer = 0 To textBoxList.Count - 1
sb.Append(textBoxList.Item(index).Name & " Parent = " & textBoxList.Item(index).Parent.Name & System.Environment.NewLine)
Next
RichTextBox1.Text = sb.ToString
End Sub
Private Function GetAllControls(Of T)(ByVal searchWithin As Control) As List(Of Control)
Dim returnList As New List(Of Control)
If searchWithin.HasChildren = True Then
For Each ctrl As Control In searchWithin.Controls
If TypeOf ctrl Is T Then
returnList.Add(ctrl)
End If
returnList.AddRange(GetAllControls(Of T)(ctrl))
Next
ElseIf searchWithin.HasChildren = False Then
For Each ctrl As Control In searchWithin.Controls
If TypeOf ctrl Is T Then
returnList.Add(ctrl)
End If
returnList.AddRange(GetAllControls(Of T)(ctrl))
Next
End If
Return returnList
End Function
End Class
Create Method
public static IEnumerable<Control> GetControlsOfType<T>(Control control)
{
var controls = control.Controls.Cast<Control>();
return controls.SelectMany(ctrl => GetControlsOfType<T>(ctrl)).Concat(controls).Where(c => c is T);
}
And use it Like
Var controls= GetControlsOfType<TextBox>(this);//You can replace this with your control
You can use the below Code
public static class ExtensionMethods
{
public static IEnumerable<T> GetAll<T>(this Control control)
{
var controls = control.Controls.Cast<Control>();
return controls.SelectMany(ctrl => ctrl.GetAll<T>())
.Concat(controls.OfType<T>());
}
}
I combined a bunch of the previous ideas into one extension method. The benefits here are that you get the correctly typed enumerable back, plus inheritance is handled correctly by OfType().
public static IEnumerable<T> FindAllChildrenByType<T>(this Control control)
{
IEnumerable<Control> controls = control.Controls.Cast<Control>();
return controls
.OfType<T>()
.Concat<T>(controls.SelectMany<Control, T>(ctrl => FindAllChildrenByType<T>(ctrl)));
}
I'd like to amend PsychoCoders answer: as the user wants to get all controls of a certain type we could use generics in the following way:
public IEnumerable<T> FindControls<T>(Control control) where T : Control
{
// we can't cast here because some controls in here will most likely not be <T>
var controls = control.Controls.Cast<Control>();
return controls.SelectMany(ctrl => FindControls<T>(ctrl))
.Concat(controls)
.Where(c => c.GetType() == typeof(T)).Cast<T>();
}
This way, we can call the function as follows:
private void Form1_Load(object sender, EventArgs e)
{
var c = FindControls<TextBox>(this);
MessageBox.Show("Total Controls: " + c.Count());
}
Although several other users have posted adequate solutions, I'd like to post a more general approach that may be more useful.
This is largely based on JYelton's response.
public static IEnumerable<Control> AllControls(
this Control control,
Func<Control, Boolean> filter = null)
{
if (control == null)
throw new ArgumentNullException("control");
if (filter == null)
filter = (c => true);
var list = new List<Control>();
foreach (Control c in control.Controls) {
list.AddRange(AllControls(c, filter));
if (filter(c))
list.Add(c);
}
return list;
}
Here is a tested and working generic solution:
I have a large number UpDownNumeric controls, some in the main form, some in groupboxes within the form. I want only the one last selected control to change back-color to green, for which I first set all others to white, using this method: (can also expand to grandchildren)
public void setAllUpDnBackColorWhite()
{
//To set the numericUpDown background color of the selected control to white:
//and then the last selected control will change to green.
foreach (Control cont in this.Controls)
{
if (cont.HasChildren)
{
foreach (Control contChild in cont.Controls)
if (contChild.GetType() == typeof(NumericUpDown))
contChild.BackColor = Color.White;
}
if (cont.GetType() == typeof(NumericUpDown))
cont.BackColor = Color.White;
}
}
Here is my extension method for Control, using LINQ, as an adaptation of @PsychoCoder version:
It takes a list of type instead that allows you to not need multiple calls of GetAll to get what you want. I currently use it as an overload version.
public static IEnumerable<Control> GetAll(this Control control, IEnumerable<Type> filteringTypes)
{
var ctrls = control.Controls.Cast<Control>();
return ctrls.SelectMany(ctrl => GetAll(ctrl, filteringTypes))
.Concat(ctrls)
.Where(ctl => filteringTypes.Any(t => ctl.GetType() == t));
}
Usage:
// The types you want to select
var typeToBeSelected = new List<Type>
{
typeof(TextBox)
, typeof(MaskedTextBox)
, typeof(Button)
};
// Only one call
var allControls = MyControlThatContainsOtherControls.GetAll(typeToBeSelected);
// Do something with it
foreach(var ctrl in allControls)
{
ctrl.Enabled = true;
}
I'm saldy using VB so, I wrote an extension method. That retrieve all children and sub children of a control
Imports System.Runtime.CompilerServices
Module ControlExt
<Extension()>
Public Function GetAllChildren(Of T As Control)(parentControl As Control) As IEnumerable(Of T)
Dim controls = parentControl.Controls.Cast(Of Control)
Return controls.SelectMany(Of Control)(Function(ctrl) _
GetAllChildren(Of T)(ctrl)) _
.Concat(controls) _
.Where(Function(ctrl) ctrl.GetType() = GetType(T)) _
.Cast(Of T)
End Function
End Module
Then you can use it like, where "btnList" is a control
btnList.GetAllChildren(Of HtmlInputRadioButton).FirstOrDefault(Function(rb) rb.Checked)
In this case, it will select the selected radio button.
Source: Stackoverflow.com