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Method with generic and multiple parameters

I want to enable/disable controls in a Windows Forms application according to the user privileges.
Initially I thought of writing a method in each form class that would check the user credentials and then enable/disable its controls. But then I realized I could (maybe) create a static class method which would take the form as a parameter and do the job.
So I started writing it, presuming that sometimes I would like to enable the controls of just one or two panels, instead of the whole form. So, I need the parameters to be:
a varying number of panels and/or
a form class.
My difficulties with this task is that I'm getting an error trying to make the panels argument varying, and I have no idea how to set a parameter that could take any form class. All my form classes obviously inherits from Form generic class, but I don't know how to apply this.
Here's what I got:
public static void Enable(TableLayoutPanel[] containers = null)
{
if (MyOF.isEnabled)
{
return;
}
else
{
try
{
foreach (TableLayoutPanel table in containers)
{
foreach (Control control in table.Controls)
{
control.Enabled = false;
}
}
}
catch (NullReferenceException)
{
}
}
}

If we remember that the Form class derives from Control (indirectly, by deriving from ContainerControl which derives from ScrollableControl, which derives from Control), and the Enabled property belongs to the Control class, we can write a method that will enable any control's children (including the Form or TableLayoutPanel controls), since the Controls collection also belongs to the Control class:
public static void EnableChildren(Control control, bool enabled = true)
{
foreach (Control child in control.Controls)
{
child.Enabled = enabled;
}
}
And then if we also want to be able to use this with a collection of controls (as in your example), we can write an overload that takes a collection:
public static void EnableChildren(IEnumerable<Control> controls = null,
bool enabled = true)
{
if (controls == null) return;
foreach (var control in controls)
{
EnableChildren(control, enabled);
}
}
Now we can use this with a Form or a collection of TableLayoutPanel controls (or any control that has controls in it's Controls collection).
Examples of usage:
var myForm = new Form1();
EnableChildren(this); // 'this' is the current form
EnableChildren(myForm); // a separate instance of a form control
EnableChildren(tableLayoutPanel1, false); // A single TableLayoutPanel control
var tableLayoutPanels = new [] {tableLayoutPanel1, tableLayoutPanel2, tableLayoutPanel3};
EnableChildren(tableLayoutPanels); // An array of tableLayoutPanel controls

One of the simple ways I can think about what you are trying to do, is this. Let me get away for a sec here. I worked on projects where all form controls were built from Metadata. And meta came with licensing info. So, when control was placed where it should, it also was disabled or set read-only based on Metadata but the whole feature would be hidden if licensing info was restricting access to it. Coming back to your approach, this is not a bad approach and I see that this is can be done. And it can be done in 2 ways, (quickly from my head).
Use user controls as surface for the components you want to enable/disable. Create an interface
public interface IDisableableControl // make your fine name, no methods needed - marker interface
. . . . .
public class MyFineUserControl : UserControl, IDisableableControl
And in your static method that you're going to write pass the form, and find all controls that implement this interface and work them the way you want.
2.
Similarly, you can use property Tag, which is available on each control. With that, you can actually set your complex security object that can come from DB-stored metadata and then you evaluate this object stored in Tag to apply your configuration
Your method needs to be recursive
internal static void SetAllControls(Control parent)
{
// Do something with control, for example parent.Enabled = false
if (parent is IDisableableControl)
{
// here you use your logic, evaluate your parent you're dialing with and
// enable/disable correspondingly
parent.Enabled = false;
return;
}
foreach(var c in parent.Controls)
SetAllControls(c);
}
In real life, your TOP parent will be a form and will not need to be disabled, but it's certain children will. In fact, most of the time, once you found a UserControl which implements IDisableableControl that should be end of line, means, you don't need to go into children controls as they all sit on this parent and all will be disabled

I manage to accomplish what I was trying to do with the code below, which is pretty much a blend of all the helpful answers I got:
public static void EnableContainer(params Control[] containers)
{
if(containers.Count() == 0) { return; }
if (MyOF.isEnabled)
{
return;
}
else
{
try
{
foreach (var container in containers)
{
foreach (Control control in container.Controls)
{
control.Enabled = false;
}
}
}
catch (NullReferenceException)
{
}
}
}
public static void EnableForm<form>(form f) where form : Form
{
if (MyOF.isEnabled)
{
return;
}
else
{
foreach(Control control in f.Controls)
{
control.Enabled = false;
}
}
}
The community is welcome to suggest improvements as I am far from being a professional programmer. Thanks everyone once again.

How to modify control properties through variable reference

I've been working on making a project of mine more modular. Something I've wanted to do is have multiple buttons use the same function when they perform a similar action, but with different values. I've been stuck on trying to apply this to the following situation:
"When this button is clicked, have the user select an image, and then have a PictureBox display the selected image". Each button has its own PictureBox. All Controls have been created before runtime.
Hope that makes sense!
My last attempt can be seen in the code below- I have tried assigning the Controls(Button and PictureBox) to variables to be stored together in a class. There's 6 of these classes all included within a single List.
I've also tried to store only the Control Names and then using this.Controls.Find to retrieve the Controls.
I've tried quite a few smaller changes such as passing by reference, making the List static, and things such as that would (somehow)magically do the trick- I've gotten desperate.
public class score_control
{
public Button score_button;
public PictureBox score_picture;
public int picture_index;
}
public List<string> score_boxes_names = new List<string>();
public List<score_control> score_boxes = new List<score_control>();
public void add_score_control(Button button, PictureBox pictureBox)
{
score_control new_score = new score_control();
new_score.score_button = button;
new_score.score_picture = pictureBox;
new_score.picture_index = score_boxes.Count();
score_boxes.Add(new_score);
score_boxes_names.Add(button.Name);
}
public score_control find_score_control(string name)
{
int index = score_boxes_names.IndexOf(name);
return score_boxes[index];
}
public frm_settings()
{
InitializeComponent();
add_score_control(btn_score1_image1, pic_score1_image1);
add_score_control(btn_score1_image2, pic_score1_image2);
add_score_control(btn_score1_image3, pic_score1_image3);
add_score_control(btn_score2_image1, pic_score2_image1);
add_score_control(btn_score2_image2, pic_score2_image2);
add_score_control(btn_score2_image3, pic_score2_image3);
}
private void score_button_Click(object sender, EventArgs e)
{
Button image_button = (Button)sender;
if (ofd_png.ShowDialog() == DialogResult.OK)
{
score_control clicked_control = find_score_control(image_button.Name);
score_image[clicked_control.picture_index] = ofd_png.FileName;
clicked_control.score_picture.Image = Image.FromFile(ofd_png.FileName);
}
}
The problem seems centered around this line:
clicked_control.score_picture.Image = Image.FromFile(ofd_png.FileName);
The program throws a NullReferenceException , but clickedcontrol is being recognized in the Local Watch, as well as score_image being noted to be a PictureBox(as it should be).
When I instead held the Control Names in the class, I had broke this line down into multiple lines, but the following line produced a NullReferenceException:
Control[] find_control = this.Controls.Find(clicked_control.score_picture, true);
In this case, clicked_control.score_picture would be a string containing the PictureBox Name. Again, the Local Watch showed that it clicked_control was not null, and neither was score_picture.
Any help figuring out how to properly store a Control within a variable to later be used to modify that Control's properties would be greatly appreciated.

dontpanic was able to help me out with this one. The issue was actually outside of this code - it had to do with the line score_image[clicked_control.picture_index] = ofd_png.FileName;. The way score_image was initialized as an array was incorrect. Fixing that made everything work fine.

how to pass a datagridview value after double clicking to a textbox on another form

Im working on a complex ribbon application, so far it is going well but now I have a litle tricky situation where I have to pass value of a DataGridView to a TextBox on another Form after double clicking the the DataGridView.

You have quite a few options actually. And it all depends on the code/architecture of your application, but generally what you are looking for are delegates.
here is an introductory level article for delegates: link. And here is a link to some basic examples which will introduce you to Actions and Lambdas as well.
Or, if those two Forms can see each other (if you have references for both forms in one parent), you can create an event on the source form and subscribe to it on the destination form, and pass the data in that manner.
The Source Form:
• Define the delegate
public delegate void RibbonDataHandler(string);
• Define the event
public event RibbonDataHandler RibbonData;
• Define the method to execute the event
protected virtual void OnRibbonData( string value )
{
if( RibbonData != null )
RibbonData( value );
}
• Invoke the event on the DoubleClick event handler of the DataGridView
string value = // Get Value from the gridView
OnRibbonData( value );
The Destination Form:
• Add a public property to set the TextBox value
public string TextBoxValue
{
get { return txtValue.Text; }
set { txtValue.Text = value; }
}
The Parent Form:
• add those two forms as fields
private Form _sourceForm;
private Form _destinationForm;
• Initialize the forms
// Well, initialize the forms in the way you need it, maybe on the Load event?
_sourceForm = new SourceForm();
_destinationForm = new DestinationForm();
_sourceForm.RibbonData += new SourceForm.RibbonDataHandler(OnRibbonData);
• Define the RibbonData Handler
private void OnRibbonData( string value )
{
_destinationForm.TextBoxValue = value ?? String.Empty;
}
Disclaimer:
I wrote all of this out of my head, did not have VS at this moment, if you have more questions or if something is not working, leave a comment. :)

Click a custom control and show some variables related to it in another control

in my Win Forms app I create an array of dynamic custom controls inside a loop. These, lets call them 'boxes', are like my basic pieces of information. I also create string arrays in other parts of the code that contain the information of this 'boxes', so that for example string[3] is a variable of box[3] and so does stringa[3], stringb[3], stringc[3]... all the arrays with the same index are related to the box with that index. Hope I make myself clear.
Only 2 of this strings are shown in 2 labels inside each custom control 'box' in the array, but the others are there because I want to make something so that when the user clicks one of these controls the other strings can be shown in another control. Sort of something like "More Information...". All the 'boxes' in the array need to have the same event handler because I create +100.
To put it more into context, each custom control 'box' in the array shows the Symbol and the Price of a stock and I want that when the user clicks on each stock more quote information is shown on another special control which is like a placeholder for "More info".
I am thinking of 2 ways to do it:
If I could "detect" the index of the clicked control (which is the same in the strings related to it), I could just set this to an int j and all I have to do is show all the strings a,b,c... with index j. Unfortunately I cannot find a way to do this, maybe it is not even possible.
The other way I have thought is to create some properties for my custom control which "store" this variables, and in my app instead of assigning strings I would set properties for each control, which I could later retrieve when the control is clicked. I haven't tryed this because I don't know exactly how to do it.
What do you think? Do you know how can I achieve this or do you have a different idea that will work? Please help! Thanks in advance.

It's kind of a broad implementation question since there are countless ways you could implement something like this.
If you are creating two collections, one with the buttons and one with the information, you potentially could just assign each of the buttons 'Tag' properties to point to the corresponding info and assign a generic OnClick event handler that displays the info.. something like:
infoControl.text = ((InfoClass)((Button)Sender.Tag)).pieceOfInformation;
But again there are many ways to do this, and the choice comes down to how you store your information.

For your first method, you could have a property of your custom control that is the index.
public class Box : Control
{
// ...existing code
private int index;
public int Index
{
get
{
return index;
}
set
{
index = value;
}
}
}
OR
For your second method, you could have a property of your custom control that is the additional info string.
public class Box : Control
{
// ...existing code
private string extraInfo;
public string ExtraInfo
{
get
{
return extraInfo;
}
set
{
extraInfo = value;
}
}
}
In either case, you could then access the proper information right in your click handler for the "box".

i don't know about the first way - got to noodle around more, but in the second way you can extended your custom or built-in control: for example:
public class ExtendedLabel: Label
{
public string[] MoreInfo { get; set; }
}
and initialize it
public TestForm()
{
InitializeComponent();
ExtendedLabel label = new ExtendedLabel();
label.MoreInfo = new string[] { "test" };
this.Controls.Add(label);
label.AutoSize = true;
label.Location = new System.Drawing.Point(120, 87);
label.Name = "label1";
label.Size = new System.Drawing.Size(35, 13);
label.TabIndex = 0;
label.Text = label.MoreInfo[0];
}
And later in your event handler you can use the inside information

C# syntax to get access to webcontrol in different file (aspx)

Within my Website project, I have some aspx pages, javascript files, and a custom C# class I called MyCustomReport. I placed a Image box with an ID of Image1 inside SelectionReport.aspx. I need to get access to that Image1 inside MyCustomReport.cs so I can turn it on and off based on conditions. What code do I need to do this? Thanks everyone

You'll need to pass the instance of Image control to MyCustomReport. From there you'll be able to set it's Visible property to true or false.
Probably something like this
public partial class SelectionReport : Page
{
// your code here
protected void Page_Load( object sender, EventArgs e ){
MyCustomReport myCustomReport = new MyCustomReport();
myCustomReport.MyReport( Image1 );
}
}
public class MyCustomReport
{
public void MyReport( Image arg ){
// some more code
arg.Visible = false; // or true
}
}
EDIT derek is right, you won't need the entire page, just the image.

it sounds a bit odd to do it that way. You could pass the control to the class method using the ref keyword, then the class could modify it:
doSomething(data, MyUserControl);
I think a better implementation would be for your class to have a method or property that the page could query to turn the control on or off.