I have a user control with a textbox in a win forms application.
I would like to change the property of that textbox using the properties window of visual studio .
I am using that control in various forms of same project ,is it possible?
I have set the modifier property of text box as public and set following property in the user control:
public TextBox mytextBox
{
get { return textBox1; }
set { textBox1 = value; }
}
Thanks in Advance.
What is the intent of doing this? Are you trying to have "one TextBox control shared by multiple forms" (that is not really practical). However you can set up your forms in such a way as to have all forms update in response to a single change.
[TypeConverter(typeof(ExpandableObjectConverter))]
public TextBox mytextBox
{
get { return textBox1; }
set { textBox1 = value; }
}
Notes:
From the perspective of the PropertyGrid, the setter has no benefit in this case; the properties of the already-assigned TextBox are being modified in-place.
Remember to create an initial value, and to add the TextBox to the UserControl's control-collection. If you used the VS designer to create the TextBox, this should have been done already. If you find that the VS designer method InitializeComponents() is undoing your changes, create and add the control yourself.
You may have to rebuild the project and/or reopen the Forms designer for the change to be visible.
Off-topic: Use Pascal-case for properties, and the auto-implemented get;set; pattern for readability, if at all possible.
Related
I am trying to add some fields to a custom UserControl that I am making. I have some fields that I like them to be visible in the Properties window of Visual Studio. I tried to use the flags below but I dont see the field in the designer, even after a compile.
How should I do this correctly?
public partial class TosChartControl: UserControl
{
#region PUBLIC FIELDS
[Browsable(true)] //Added this but still does not show up
[Category("Data")]
[DefaultValue(0)]
[Description("ID of the Sensor Node")]
public int NodeId { get; set; }
#endregion
public TosChartControl()
{
InitializeComponent();
}
}
I did clean and rebuild the soloution and projects but I cant still see this field in Properties window. Even restarting the Visualstudio didnt help.
UPDATE: Your public properties are visible in the designer only when it's in another control in the designer. It turns out that you don't need to add this attribute, properties are visible by default in the designer. As far as I understand, when it's in another component's design view, an instance of the user control is created and properties can be shown. Sorry for misleading you in the beginning, I thought it was necessary to add it.
Try this attribute:
[Browsable(true)]
http://msdn.microsoft.com/en-us/library/system.componentmodel.browsableattribute.aspx
To elaborate on henginy's updated answer:
Be sure that you are looking at an instance of the control you want to modify properties for, and not the definition of the control itself.
To clarify, when you add a property to your TosChartControl class, you won't see the property in the TosChartControl.cs [Design] tab, you will see it where you implement a TosChartControl, such as your Form1.cs [Design] tab, e.g. the containing control to which you have added your custom control.
...Assuming that your Properties window is visible, and that you have the control selected.
What to take away from this lesson:
Understanding what the properties window is actually showing you — It's contextual.
The difference between the model and the implementation of the model — e.g. Designing the custom control and designing the form that uses the custom control.
I have a custom control with a bool property. In the designer, I drag the user control to a form and I change this property to "false", which is supposed to hide a child control.
It is indeed hiding it in runtime, but not in design time. How could I "refresh" my user control in design time to reflect the changes to this property?
I don't know why you want to do this. The Control will only be hidden at runtime and this is how it was meant to be. Maybe you can create something to hide it at Design-Time or add another control over it to hide it.
How could I "refresh" my user control in design time to reflect the changes to this property?
You can't. Changes apply automatically the only reason why you still see it is because that's how it should be.
This worked as is using Visual Studio 2012:
public class TestControl : Control {
Button button;
public TestControl() {
button = new Button() { Text = "Click" };
this.Controls.Add(button);
}
public bool ButtonVisible {
get { return button.Visible; }
set {
button.Visible = value;
}
}
}
I'm afraid I didn't ask my question correctly - I was inheriting from a rather complex third-party control and I wanted to see a change in design time.
I ended up overriding OnCreateControl. I appreciate your help nevertheless.
I have a main form with some buttons, textboxes, labels, etc.
On a second form I would like to copy the text from the main forms textbox onto the second form.
Have tried:
var form = new MainScreen();
TextBox tb= form.Controls["textboxMain"] as TextBox;
textboxSecond.Text = tb.Text;
But it just causes an exception. The main screen textbox is initialised and contains text.
When I hover over form I can see all the controls are there.
What am I doing wrong?
Looking at the original code, there are two potential reasons for the NullReferenceException you are getting. First, tb is not defined in the code you provide so I am not sure what that is.
Secondly, TextBox textbox = form.Controls["textboxMain"] as TextBox can return null if the control is not found or is not a TextBox. Controls, by default, are marked with the private accessor, which leads me to suspect that form.Controls[...] will return null for private members.
While marking the controls as internal will potentially fix this issue, it's really not the best way to tackle this situation and will only lead to poor coding habits in the future. private accessors on controls are perfectly fine.
A better way to share the data between the forms would be with public properties. For example, let's say you have a TextBox on your main screen called usernameTextBox and want to expose it publicly to other forms:
public string Username
{
get { return usernameTextBox.Text; }
set { usernameTextBox.Text = value; }
}
Then all you would have to do in your code is:
var form = new MainForm();
myTextBox.Text = form.Username; // Get the username TextBox value
form.Username = myTextBox.Text; // Set the username TextBox value
The great part about this solution is that you have better control of how data is stored via properties. Your get and set actions can contain logic, set multiple values, perform validation, and various other functionality.
If you are using WPF I would recommend looking up the MVVM pattern as it allows you to do similar with object states.
PhoenixReborn is correct. The problem is that you are creating a new MainScreen, which means that new controls are created, so unless the text in your controls are initialized in the form constructor, they are going to be empty. Usually, the way to handle this is to pass the first form instance to the second form, like this:
SecondForm second = new SecondForm(this);
and in the second form:
public SecondForm (MainForm form)
{
// do something with form, like save it to a property or access it's controls
}
That way, the second form will have access to the first form's controls. You might consider making the properties you need to use public (in the designer properties pane). That way you can just do form.textboxMain.Text.
I have created a customize windows form and I just don't know how should I set properties to it.
for example I've created a form with a progress bar, button, and a label and want to set the text of the label, the value of the progress bar, and to get access to the buttonClick Event method form the windows form application that uses the control.
In other words just get access to all the default properties of each control inside.
Is it possible? and how should I do it?
thanks very much!
If I want to to get access to the buttonClick Event method how should I do it?
You need to cast from Control to the type of your custom control before you can access the properties you have defined.
var myCtrl = (MyControl)controlRef;
myCtrl.MyProperty = xxxx;
This code assumes that MyProperty has been declared as public.
If I understand your question correctly, you want to expose controls on a form to outside code.
One way to achieve this would be to declare accessible properties on the form, for example:
public ProgressBar MyProgressBar
{
get { return progressBar1; }
}
If you wish to only expose certain properties of the controls, you could also have properties that access these directly, like so:
public int MyProgressBarValue
{
get { return progressBar1.Value; }
set { progressBar1.Value = value; }
}
I have an initial value property like this:
[Category("Main")]
[Description("Intial Value")]
[DefaultValue(10)]
public int InitialValue
{
get { return m_initialValue; }
set {
m_initialValue = value;
this.TrackBar.Value = this.m_initialValue;
}
}
So in my constructor I do this for example:
this.InitialValue = 10;
To my surprise when dragging the custom control on a form the setter is not called so that my trackbar value is not synchronized.
Why ?
Only when I change the property in dialog box the setter is called.
I decided to take your advice as suggested in one of the comments:
You can try by yourself will take 2 minutes.
So I did (it took about 3 minutes), and I was unable to reproduce the behavior that you described.
Here are the exact steps that I followed:
Created a new Windows Forms Application.
Added a new User Control to my project.
Opened the new User Control in design view and added a TrackBar control (leaving the TrackBar control's properties all set to their defaults).
Added the following code to the User Control class (exactly the same as you posted above, with the addition of a private field m_initialValue that you omitted from the original example):
public class UserControl1 : UserControl
{
public UserControl1()
{
InitializeComponent();
this.InitialValue = 10;
}
[Category("Main")]
[Description("Intial Value")]
[DefaultValue(10)]
public int InitialValue
{
get { return m_initialValue; }
set
{
m_initialValue = value;
this.trackBar1.Value = this.m_initialValue;
}
}
int m_initialValue;
}
Built the project.
Opened the default Form (Form1) that was created with the new project in design view.
Dragged the User Control that I had just created (UserControl1) out of the toolbox where it was automatically placed and onto the surface of the form.
The indicator on the slider bar appeared all the way to the right side (the correct and expected position given the default Maximum value of 10). Now, you tell me: What are we doing differently?
Try adding [Browsable(true)] .
The key portion of your question is here:
when dragging the custom control on a form
You're still in the designer, and the designer cheats a bit to render things. Does this still happen when you actually run the application?