I don't get the option .Image when I apply this code:
foreach(Control b in _SelectionPanel.Controls)
{
if (b is Button)
{
b.Image = null;
}
}
However, I can get the option 'Visible':
foreach(Control b in _SelectionPanel.Controls)
{
if (b is Button)
{
b.Visible = false;
}
}
I'm trying to remove all the images from the buttons in a control group. Any ideas?
is only checks if the type is Button.
You want to use as to perform the actual cast, hence allowing you to access Button's properties. If the cast is invalid, you will simply get a null reference, so simply perform the as cast, then check if your variable is null before using it.
foreach(Control b in _SelectionPanel.Controls)
{
Button castB = b as Button;
if (castB != null)
{
castB.Image = null;
}
}
foreach(var b in _SelectionPanel.Controls.OfType<Button>())
{
((Button)b).Image = null;
}
You can iterate over controls of type button only and then explicitly cast var to Button.
In the context of your loop, b is a control. Even after checking. To get the Image property, you need to cast it to the Button type:
foreach(Control b in _SelectionPanel.Controls)
{
if (b is Button)
{
((Button)b).Image = null;
//Alternatively
(b as Button).Image = null;
}
}
Related
I have a ToolStripMenuItem called myMenu. How can I access this like so:
/* Normally, I would do: */
this.myMenu... etc.
/* But how do I access it like this: */
String name = myMenu;
this.name...
This is because I am dynamically generating ToolStripMenuItems from an XML file and need to reference MenuItems by their dynamically generated names.
Use the Control.ControlCollection.Find method.
Try this:
this.Controls.Find()
string name = "the_name_you_know";
Control ctn = this.Controls[name];
ctn.Text = "Example...";
Assuming you have the menuStrip object and the menu is only one level deep, use:
ToolStripMenuItem item = menuStrip.Items
.OfType<ToolStripMenuItem>()
.SelectMany(it => it.DropDownItems.OfType<ToolStripMenuItem>())
.SingleOrDefault(n => n.Name == "MyMenu");
For deeper menu levels add more SelectMany operators in the statement.
if you want to search all menu items in the strip then use
ToolStripMenuItem item = menuStrip.Items
.Find("MyMenu",true)
.OfType<ToolStripMenuItem>()
.Single();
However, make sure each menu has a different name to avoid exception thrown by key duplicates.
To avoid exceptions you could use FirstOrDefault instead of SingleOrDefault / Single, or just return a sequence if you might have Name duplicates.
Control GetControlByName(string Name)
{
foreach(Control c in this.Controls)
if(c.Name == Name)
return c;
return null;
}
Disregard this, I reinvent wheels.
Using the same approach of Philip Wallace, we can do like this:
public Control GetControlByName(Control ParentCntl, string NameToSearch)
{
if (ParentCntl.Name == NameToSearch)
return ParentCntl;
foreach (Control ChildCntl in ParentCntl.Controls)
{
Control ResultCntl = GetControlByName(ChildCntl, NameToSearch);
if (ResultCntl != null)
return ResultCntl;
}
return null;
}
Example:
public void doSomething()
{
TextBox myTextBox = (TextBox) this.GetControlByName(this, "mytextboxname");
myTextBox.Text = "Hello!";
}
I hope it help! :)
this.Controls.Find(name, searchAllChildren) doesn't find ToolStripItem because ToolStripItem is not a Control
using SWF = System.Windows.Forms;
using NUF = NUnit.Framework;
namespace workshop.findControlTest {
[NUF.TestFixture]
public class FormTest {
[NUF.Test]public void Find_menu() {
// == prepare ==
var fileTool = new SWF.ToolStripMenuItem();
fileTool.Name = "fileTool";
fileTool.Text = "File";
var menuStrip = new SWF.MenuStrip();
menuStrip.Items.Add(fileTool);
var form = new SWF.Form();
form.Controls.Add(menuStrip);
// == execute ==
var ctrl = form.Controls.Find("fileTool", true);
// == not found! ==
NUF.Assert.That(ctrl.Length, NUF.Is.EqualTo(0));
}
}
}
One of the best way is a single row of code like this:
In this example we search all PictureBox by name in a form
PictureBox[] picSample =
(PictureBox)this.Controls.Find(PIC_SAMPLE_NAME, true);
Most important is the second paramenter of find.
if you are certain that the control name exists you can directly use it:
PictureBox picSample =
(PictureBox)this.Controls.Find(PIC_SAMPLE_NAME, true)[0];
You can use find function in your Form class. If you want to cast (Label) ,(TextView) ... etc, in this way you can use special features of objects. It will be return Label object.
(Label)this.Controls.Find(name,true)[0];
name: item name of searched item in the form
true: Search all Children boolean value
this.Controls["name"];
This is the actual code that is ran:
public virtual Control this[string key]
{
get
{
if (!string.IsNullOrEmpty(key))
{
int index = this.IndexOfKey(key);
if (this.IsValidIndex(index))
{
return this[index];
}
}
return null;
}
}
vs:
public Control[] Find(string key, bool searchAllChildren)
{
if (string.IsNullOrEmpty(key))
{
throw new ArgumentNullException("key", SR.GetString("FindKeyMayNotBeEmptyOrNull"));
}
ArrayList list = this.FindInternal(key, searchAllChildren, this, new ArrayList());
Control[] array = new Control[list.Count];
list.CopyTo(array, 0);
return array;
}
private ArrayList FindInternal(string key, bool searchAllChildren, Control.ControlCollection controlsToLookIn, ArrayList foundControls)
{
if ((controlsToLookIn == null) || (foundControls == null))
{
return null;
}
try
{
for (int i = 0; i < controlsToLookIn.Count; i++)
{
if ((controlsToLookIn[i] != null) && WindowsFormsUtils.SafeCompareStrings(controlsToLookIn[i].Name, key, true))
{
foundControls.Add(controlsToLookIn[i]);
}
}
if (!searchAllChildren)
{
return foundControls;
}
for (int j = 0; j < controlsToLookIn.Count; j++)
{
if (((controlsToLookIn[j] != null) && (controlsToLookIn[j].Controls != null)) && (controlsToLookIn[j].Controls.Count > 0))
{
foundControls = this.FindInternal(key, searchAllChildren, controlsToLookIn[j].Controls, foundControls);
}
}
}
catch (Exception exception)
{
if (ClientUtils.IsSecurityOrCriticalException(exception))
{
throw;
}
}
return foundControls;
}
Assuming you have Windows.Form Form1 as the parent form which owns the menu you've created. One of the form's attributes is named .Menu. If the menu was created programmatically, it should be the same, and it would be recognized as a menu and placed in the Menu attribute of the Form.
In this case, I had a main menu called File. A sub menu, called a MenuItem under File contained the tag Open and was named menu_File_Open. The following worked. Assuming you
// So you don't have to fully reference the objects.
using System.Windows.Forms;
// More stuff before the real code line, but irrelevant to this discussion.
MenuItem my_menuItem = (MenuItem)Form1.Menu.MenuItems["menu_File_Open"];
// Now you can do what you like with my_menuItem;
Since you're generating them dynamically, keep a map between a string and the menu item, that will allow fast retrieval.
// in class scope
private readonly Dictionary<string, ToolStripMenuItem> _menuItemsByName = new Dictionary<string, ToolStripMenuItem>();
// in your method creating items
ToolStripMenuItem createdItem = ...
_menuItemsByName.Add("<name here>", createdItem);
// to access it
ToolStripMenuItem menuItem = _menuItemsByName["<name here>"];
Have a look at the ToolStrip.Items collection. It even has a find method available.
You can do the following:
private ToolStripMenuItem getToolStripMenuItemByName(string nameParam)
{
foreach (Control ctn in this.Controls)
{
if (ctn is ToolStripMenuItem)
{
if (ctn.Name = nameParam)
{
return ctn;
}
}
}
return null;
}
A simple solution would be to iterate through the Controls list in a foreach loop. Something like this:
foreach (Control child in Controls)
{
// Code that executes for each control.
}
So now you have your iterator, child, which is of type Control. Now do what you will with that, personally I found this in a project I did a while ago in which it added an event for this control, like this:
child.MouseDown += new MouseEventHandler(dragDown);
I am making a Winforms application. Because I want to redraw some borders I want to loop through the controls and check which controls have a border. Unfortunately I have no idea how to accomplish this.
I know panels and textboxes, etc. have a property BorderStyle but I can not access it while looping through Controls. I use the function from this link : https://learn.microsoft.com/en-us/dotnet/api/system.windows.forms.control.controls?view=netframework-4.8 , to loop through the controls.
If you have a panel you can foreach on the panel. I use form load as an event
private void Form1_Load(object sender, EventArgs e)
{
foreach (var item in this.Controls)
{
switch (item.GetType().Name)
{
case "Label":
if (((Label)item).BorderStyle == BorderStyle.None)
{
//Your commands
}
break;
case "TextBox":
if (((TextBox)item).BorderStyle == BorderStyle.None)
{
//Your commands
}
break;
}
}
}
Or you can check them dynamic
I recommend you to use the dynamic way.
in this way, your app wouldn't encounter exceptions or errors
foreach (var item in this.Controls)
{
//Get item from form
dynamic element = item;
//check if there is any property called Borderstyle exists
var res = item.GetType().GetProperties().Where(p => p.Name.Equals("BorderStyle")).FirstOrDefault();
//if it exists and value is not equal None(Control have border)
if (res !=null && !(res.GetValue(item).Equals("None")))
{
res.SetValue(item, BorderStyle.FixedSingle, null);
//your other commands
}
}
You could use a foreach for every type of control you use (TextBox, Label, etc.)
var controlsWithoutBorders = new List<Control>();
// Check textboxes
foreach (var control in controls.OfType<TextBox>())
{
if (control.BorderStyle != BorderStyle.None)
{
controlsWithoutBorders.Add(control);
}
}
//Check labels
foreach (var control in controls.OfType<Label>())
{
if (control.BorderStyle != BorderStyle.None)
{
controlsWithoutBorders.Add(control);
}
}
Alternatively, you could use a single foreach on all the controls, and try to cast the control to each type. The cast will be successful if the control is actually what you want to cast it to, otherwise it will return null (e.g. trying to cast a Control that is a TextBox to a Label will return null)
var controlsWithoutBorders = new List<Control>();
foreach (var control in controls)
{
var controlAsTextBox = control as TextBox;
var controlAsLabel = control as Label;
if (controlAsTextBox != null && controlAsTextBox.BorderStyle != BorderStyle.None)
{
controlsWithBorders.Add(control);
}
if (controlAsLabel != null && controlAsLabel.BorderStyle != BorderStyle.None)
{
controlsWithBorders.Add(control);
}
}
Though this method is not the fastest at run time, your problem could be cleanly solved with the use of C#'s dynamic typing feature. Consider the below snippet of code.
public void DealWithBorder(List<Control> lsControls) {
foreach(var element in lsControls){
dynamic dynamicElement = element;
try{
BorderStyle style = dynamicElement.BorderStyle;
// Handle if property does exist in the control
}
catch{
// Handle if property doesnt exist in the control
}
}
}
In English, it will try to act as if the property exists in the object but if it does not, an exception will thrown. For more info on dynamic typing, click here.
I have a GroupBox which has 3 TextBoxes and 3 Labels
the name of the group box is TextInfoGroupBox ..
I'm trying to access the textBoxes inside it, but I just don't seem to know how ..
I tried something like:
TextInfoGroupBox.innerTextbox;
TextInfoGroupBox.Controls.GetChildControl;
Both of these didn't pop up in the intellisence ..
how can i reach them, set and get data from them ?
You can access them just like any other control:
innerTextBox
The Visual Studio designer generates a field for each control you put in your form, regardless of nesting.
Use Controls collection for this purpose. You will need to know exactly what item in that collection is your TextBox. If there are only 3 textboxes in your groupbox you can use
groupBox.Controls[0], groupBox.Controls[1], groupBox.Controls[2]
to access your items or just use their respective names.
If you don't have direct access to innerTextBox for some reason, you can always go hunting:
TextBox myTextBox = null;
Control[] controls = TextInfoGroupBox.Controls.Find("InnerTextBoxName", true);
foreach (Control c in controls)
{
if (c is TextBox)
{
myTextBox = c as TextBox;
break;
}
}
At the end of this , if myTextBox is null, it couldn't be found (obviously). Hopefully you don't structure it so that there would be multiple entries.
You could also create some cute extension methods:
public static Control FindControl(this Control parent, string name)
{
if (parent == null || string.IsNullOrEmpty(name))
{
return null;
}
Control[] controls = parent.Controls.Find(name, true);
if (controls.Length > 0)
{
return controls[0];
}
else
{
return null;
}
}
public static T FindControl<T>(this Control parent, string name) where T : class
{
if (parent == null || string.IsNullOrEmpty(name))
{
return null;
}
Control[] controls = parent.Controls.Find(name, true);
foreach (Control c in controls)
{
if (c is T)
{
return c as T;
}
}
return null;
}
And you could simply call them as
Control c = TextInfoGroupBox.FindControl("MyTextBox");
TextBox tb = TextInfoGroupBox.FindControl<TextBox>("MytextBox");
When I use th below code, it works. All the controls are hidden.
foreach (Control ctr in eItem.Controls)
{
ctr.visible = false;
}
However, I want to hide only labels and dropdownlists. That why I'm trying to use the below code without success
foreach (Control ctr in eItem.Controls)
{
if(ctr is Label | ctr is DropDownList)
{
ctr.visible = false;
}
}
EDIT
Here's the whole method
private void HideLabelAndDDLOnPageLoad()
{
foreach (ListViewItem eItem in lsvTSEntry.Items)
{
foreach (Control ctr in eItem.Controls)
{
if (ctr is Label || ctr is DropDownList)
{
ctr.Visible = false;
}
}
}
}
When I remove the if, all the controls get hidden. When I put it back, nothing happens.
Thanks for helping
I think what you are after is || change it to ||...that is the logical or operator.
foreach (Control ctr in eItem.Controls)
{
if(ctr is Label || ctr is DropDownList)
{
ctr.Visible = false;
}
}
| = bitwise operator
|| = logical or operator
Based on your edit
It appears your controls are inside an updatepanel, if that is the case you want to loop for all controls within the updatepanel's content template container.
Here you go:
foreach (Control ctr in UpdatePanel1.ContentTemplateContainer.Controls)
{
// rest of code
if(ctr is Label || ctr is DropDownList)
{
ctr.Visible = false;
}
}
The | is the bitwise or operator.
You are looking for ||, the logical or operator.
if(ctr is Label || ctr is DropDownList)
Without your exact markup we can only guess the solution here.
You must be using another container to wrap your controls inside your ItemTemplate in the ListView, something like a Panel or other containers. When you get the Controls on the list view item you actually get the warping container and not its children(labels, dropdowns etc.)
One solution to this is something like:
foreach (ListViewItem item in lsvTSEntry.Items)
{
item.FindControl("myLabel").Visible = false;
item.FindControl("myDropdownList").Visible = false;
}
Basically you try to find the controls by id and hide them. Notice there is no error checking there so you could get a NullReferenceException if FindControl returns null.
In case you have nested containers in your ItemTemplate and you want to hide all the labels and dropdowns regardless of where they are you can implement your own recursive FindControl that will look like:
private Control FindControlRecursive(Control rootControl, string controlId)
{
if (rootControl.ID == controlId)
{
return rootControl;
}
foreach (Control controlToSearch in rootControl.Controls)
{
Control controlToReturn = FindControlRecursive(controlToSearch, controlId);
if (controlToReturn != null)
{
return controlToReturn;
}
}
return null;
}
Not the most elegant but.... You can change this to take an array of Id's of course for speed purposes.
Based on this of course you can implement the search by control type which instead of taking a controlId as a parameter will take the types of controls to find.
So I have an event that can be triggered by a change of the checked value of some checkboxes and some radiobuttons. I want to get the Checked value of the control that triggered the event. I know that if it is a checkbox I can do something like bool checkedValue = (sender as CheckBox).Checked;
(and same for radiobuttons). but what if I don't know the type of the control? Is there a class for both of them?
The best approach would be to use an interface, but according to your comment on Felice Pollano's answer you don't want to.
I would then suggest to look for the type at runtime:
bool checked;
if (sender is CheckBox)
checked = ((CheckBox)sender).Checked;
if (sender is RadioButton)
checked = ((RadioButton)sender).Checked;
If you are running .NET 4 you might want to try this ugly trick:
private void checkBox1_Click(dynamic sender, EventArgs e) {
bool isChecked = sender.Checked;
textBox1.Text = isChecked ? "Checked" : "Unchecked";
}
not very type safe, but fun!
You may build a small function taking a control parameter. Then try to cast first to Check box, if not null use the Checked result. If null, try the same with radio button. If that's null too, throw an InvalidParameterException or something appropriate. Else return the value you saved.
bool GetChecked(object ctrl) {
bool result = false;
CheckBox cb = ctrl as CheckBox;
if ( null == cb ) {
RadioButton rb = ctrl as RadioButton;
if ( null == rb ) {
throw new Exception ( "ctrl is of the wrong type " );
}
result = rb.Checked;
} else {
result = cb.Checked;
}
return result;
}
Not tried to compile, just to provide the idea. Second idea: do a bit reflection, look if there's a property named Checked and get the value. Rough, untested Code:
bool GetChecked(object ctrl) {
bool result = false;
Type reflectedResult = ctrl.GetType();
PropertyInfo[] properties = reflectedResult.GetProperties();
List<System.Reflection.PropertyInfo> properties = ctrl.GetProperties ().Where ( itm => itm.Name == "Checked" ).ToList ();
if ( properties.Count == 1 )
{
bool result = (bool)properties[0].GetValue ( ctrl, null );
} else {
throw new Exception ( "ctrl is of the wrong type " );
}
return result;
}
Though I don't like the code of both...
They both derive from ButtonBase but ButtonBase does not implement IsChecked. As a suggestion create two subclass of CheckBox and RadioButton, declare an Interface, ie IHasCheck, implement it properly in your derived classes, and try to cast at this interface in the event handler:
public interface ICheckable
{
bool Checked { get; set; }
}
class RadioButtonExtended : RadioButton,ICheckable
{
}
class CheckBoxExtended : CheckBox, ICheckable
{
}