FieldInfo.CaptionStyle in custom form control not working - c#

I have created a custom form control for use in my Kentico bizform using asp.net and I want to change the field caption style of another field in the form depending upon the value in my custom form control field. So, this is what I have done:
protected void ddl_SelectedIndexChanged(object sender, EventArgs e)
{
if(this.Value == "1")
{
FormEngineUserControl formItem = (FormEngineUserControl)this.Form.FieldControls["Other"];
formItem.FieldInfo.CaptionStyle = "font-weight:bold";
}
}
However, the field caption in the form doesn't seem to get bolded. I tried testing if the event even fires and it does. Infact, if I try something like formItem.Text = "Something" then the texbox gets filled with "Something". While debugging I also noticed that the field caption style does get changed to "font-weight: bold" but that doesn't show on the form. So, there is something wrong with the captionstyle property or the way I am using it. How do I get it to work?
(Please note that the field control "Other" is a text box input)

It's probably too late in Page's lifecycle and the control has already been rendered. Try to set the CaptionStyle earlier (e.g. in control's OnLoad or OnInit) then you'll know with certainty.

Related

user control that other developers can add controls to it and "inherit" the behavior of all controls on my control

hi all and sorry for the confusing title... can't find the right words yet.
just out of curiosity, I am playing with c# user control, I created a control that is built from a panel, a textbox that is being used as a filter, and some labels / buttons/ etc... that are being filtered.
when ever you change the text of the textbox, all the controls on the panel are visible / invisible depending if their Text property contains the Text of the textbox. very simple.
but I want this user control to be such that the user that uses it can drop more labels or controls to it and they will behave the same, I can't figure out how to do that..
when I am editing the control (adding controls to it), it works as expected and the new controls behave as the old ones without code modifications, but only when I am editing the user control and not when using it.
when I am dragging the user control to a form, I can not add controls to it... when I try to add a label to the control - it is just added to the form and not to the control and therefore the text box is not influencing the added label. what should I do if I want to be able to add the control to a form and then add some controls to the control?
I will be happy for some pointers.
here is the relevant code:
private void textBox1_TextChanged(object sender, EventArgs e)
{
foreach (Control c in panel1.Controls)
{
if (c.Text.Contains(textBox1.Text))
{
c.Visible = true;
}
else
{
c.Visible = false;
}
}
}
edit - pictures added.
as you can see - i typed 1 in the filter text box and all the controls except button1 are now invisible - and of course the bad behaving label.
Thanks,
Jim.
This problem can be solved easily by following the guidelines in
https://support.microsoft.com/en-us/kb/813450 which decribes step by step How to make a UserControl object acts as a control container design-time by using Visual C#
In order to modify the user control as a design time control container
add the following code to the Declarations section:
using System.ComponentModel.Design;
Apply the System.ComponentModel.DesignerAttribute attribute to the control as follows:
[Designer("System.Windows.Forms.Design.ParentControlDesigner, System.Design", typeof(IDesigner))]
public class UserControl1 : System.Windows.Forms.UserControl
{
...
}
Then build the solution.
the control will appear as usual in the Toolbox and can be added to forms. Additional controls such as buttone , text boxes etc.. can be added to the control as required.
You describe one of the reasons why I almost never use UserControls. Anything that isn't done to the original UC must be done in code..
You can instead make it a class that is not a UserControl, ie make it a simple subclass of Panel (or FlowLayoutPanel as I do here merely for convenience, while dropping stuff on it during my tests).
class FilterPanel : FlowLayoutPanel
{
TextBox tb_filterBox { get; set; }
Label st_filterLabel { get; set; }
public FilterPanel()
{
st_filterLabel = new Label();
st_filterLabel.Text = "Filter:";
this.Controls.Add(st_filterLabel);
tb_filterBox = new TextBox();
this.Controls.Add(tb_filterBox);
// st_filterLabel.Location = new Point(10, 10); // not needed for a FLP
// tb_filterBox.Location = new Point(100, 10); // use it for a Panel!
tb_filterBox.TextChanged += tb_filterBox_TextChanged;
}
void tb_filterBox_TextChanged(object sender, EventArgs e)
{
foreach(Control ctl in this.Controls)
{
if (ctl != tb_filterBox && ctl != st_filterLabel)
ctl.Visible = ctl.Text.Contains(tb_filterBox.Text);
}
}
}
Now after placing it on a form (or whatever) you (or whoever) can drop Controls onto it in the designer and they'll be part of its Controls collection, just like you want it and will behave as expected..
Two notes on subclassing Controls:
If you break one during developement, the Form(s) using it will be broken, too, until you fix the problem. So take a little extra care!
For the Designer to display the Control it always needs to have one parameterless constructor, like the one above. Even if you prefer to have the ability to hand in parameters, one parameterless constructor must still be there or the designer will get into trouble!

Add and read Multiple textboxes

What is the best way to create and read multiple textboxes in a windows form? In my application, I have a windows form where customer can enter multiple addresses, email addresses
Right now I have a form like this,
TextBoxAddress1 TextBoxEmail1
TextBoxAddress2 TextBoxEmail2
.....
.....
.....
TextBoxAddressN TextBoxEmailN
For this I dragged and dropped multiple controls on a form and named each one of them.
If I use this method I had to write lengthy code to see if first row (TextBoxAddress1 TextBoxEmail1) is filled for validation and even for reading I had to write many lines of code.
Is there a better to way achieve this?
You can use the following code to add a TextBox dynamically to your form:
private int m_CurrTexboxYPos = 10;
private List<TextBox> m_TextBoxList = new List<TextBox>();
private void CreateCheckBox()
{
m_CurrTexboxYPos += 25;
TextBox textbox = new TextBox();
textbox.Location = new System.Drawing.Point(0, m_CurrTexboxYPos);
textbox.Size = new System.Drawing.Size(100,20);
Controls.Add(textbox);
m_TextBoxList.Add(textbox);
}
I would have a listbox/listview with your emails and Add/Edit/Delete buttons which show a popup form - the logic for validating emails, etc. would then be in the one place and your list can grow without you ever needing to add controls to the form.
You could dynamically create textboxes - but you end up writing code to make sure they layout nicely on the form, etc. - having some type of list is easier IMO and also lends itself to binding (e.g. to an email object)
Dynamically adding controls is pretty simple, provided you can use DockStyle and an exclusive container for them (e.g. a Panel). If you can't use DockStyle, then you need to write logic to determine Location and Size (which isn't fun).
On a simple form, I have two buttons and a panel, Button1 adds a new TextBox to Panel1, Button2 iterates through the controls in Panel1 and then checks that they are the correct type or throws an exception. This is where you you would put validation or reading logic. Panel1 needs to have AutoScroll = true; otherwise you will run controls off of the viewable screen.
This concept can be switched for anything that inherits from UserControl (all .Net native controls or your own custom controls).
private void button1_Click(object sender, EventArgs e)
{
TextBox NewEmailBox = new TextBox();
NewEmailBox.Name = "NewEmailBox" + this.panel1.Controls.Count;
NewEmailBox.Dock = DockStyle.Top;
this.panel1.Controls.Add(NewEmailBox);
}
private void button2_Click(object sender, EventArgs e)
{
foreach (Control item in this.panel1.Controls)
{
if (item is TextBox)
{
//Do your reading/validating here.
}
else
{
throw new InvalidCastException(string.Format("{0} was in Panel1 and is of type {1} not TextBox!", item.Name, item.GetType()));
}
}
}
Write a user control for each of the groupings you need. at least one One for address, one for email etc. then all of your validation, calls to your database access is contained in a single location
That is just good design. this way if you have multiple tabs for things like Home Information, Work Information, Emergency Contact Information, you can just place them on the form. This is pretty common for a user profile.
Then a listview for each grouping on a user profile page or whatever, that has edit/delete/add then popup a dialog with the appropriate user control in it.
Most simply, ListBox adove TextBox with Button.
Also you can use DataGridView, BuiltIn functionality for Add\Edit\Delete.
Here using DataGridView (ShowHeader set to false, EditMode to On Enter, with one Column with AutoSizeMode in Fill property)
The less of repeatable code you have, the better programmer you are.
Whenever you see a pattern (something what is repeatable), you could and you should try to optimize it. Unless it's something too small to worry.
In your case, determine first what is the basic of repeatable thing. Do you always have to enter address and email address? Then combine them into a control, which can carry out validation. Do you have to use this control often (or repeat N times)? Then maybe it make sense to switch to a list instead (ListBox, ListView or DataGridView).
Are you too lazy to bother configuring things? Then just optimize something what is obviously going to repeat: put validation into common method and call it from each TextBox event. Or make own TextBox with method build-in. Or do validation at once in the Ok button event by using loop.. or not by using loop.
To find best method you have to first decide best for who. Because customer want something shiny,easy to use, animated, with cats and boobs.. ok, without cats and boobs. The point is: how much work are you willing to put to have it best for the customer.
If I would have to enter table data (or data which form table), I'd go with DataGridView so it would looks like this.. or better:

use custom control in windows forms checked list box

The Items property of a checked list box control in Windows forms is of type object, so my naive hope was that I can add a customized User control as item. (Since, usually, my task is to write logic for background tasks I'm not too familiar with UI programming, so this may be a stupid idea..)
More precisely I want to display two labels and a button in each line of the the checked list box. The first label is supposed to display the name of an object the user can select (so that later on a specific operation will be performed on all checked items). For any item checked, the button is supposed to allow the user to choose a file from which custom settings can be read for performing that operation and the second label should display the choice the user has made using the button (i.e. the file name or something like the string "default settings").
So, in the forms designer, I created a custom control CustomControl1 with label1, label2, button1, and methods to set the text properties, set autosize of the labels and the button to false, defined their size manually. Then in the main window I created the checked list box, to which I added custom controls. The constructor of my main window now looks as follows:
InitializeComponent();
UserControl1 uc1 = new UserControl1();
uc1.setLabel1("label1_text");
uc1.setLabel2("label2_text");
uc1.setButtonText("button_text");
this.checkedListBox1.Items.Add(uc1);
uc1.Visible = true;
This compiles without any error and also runs, but the checked list box shows an empty field. I also experimented with the size of the list box. If I reduce the height so that the check box just fits into it then I do see fragments of the button in the corresponding line, but no label.
Is it possible to use a custom form in a checked list box and if yes, what am I missing?
No, you can't do this.
The listbox only shows a list of elements. The listbox uses the property .ToString() for each objects in the list to show the items.
You need to look for a custom listbox
private void Form1_Load(object sender,EventArgs e)
{
checkedListBox1.Items.Add("IIT");
checkedListBox1.Items.Add("CSE");
checkedListBox1.Items.Add("EEE");
checkedListBox1.Items.Add("ICT");
checkedListBox1.Items.Add("URP");
checkedListBox1.Items.Add("ENGLISH");
checkedListBox1.Items.Add("BANGLA");
checkedListBox1.Items.Add("MATH");
}
private void checkedListBox1_SelectedIndexChanged(object sender,EventArgs e)
{
//var item=checkedListBox1.SelectedItem;
label1.Text=checkedListBox1.SelectedItem.ToString();
}

In which event should one set dynamic control properties?

This article states that Page_PreInit should be used to
create or re-create dynamic controls.
For example:
Button button = new Button();
somePanel.Controls.Add(button);
Good. I understand.
However, it also says:
If the request is a postback, the values of the controls have not yet
been restored from view state. If you set a control property at this
stage, its value might be overwritten in the next event.
Huh?
Does this mean that all I should do is create the button, but not set any members of the button?
For example:
Button button = new Button() { CommandArgument="arg" };
somePanel.Controls.Add(button);
Does this mean that setting CommandArgument in this event is incorrect/not recommended/might cause an error/unexpected behavior?
Assuming it is incorrect, this would lead me to think that one would have to do something like this:
protected void Page_PreInit(object sender.....)
{
somePanel.Controls.Add((new Button());
}
protected void Page_Init(object sender.....)
{
foreach(Button button in somePanel.Controls)
button.CommandArgument = "arg";
}
is this the right way?
Finally, in which event should one set dynamic control properties?
There is no single answer for that last question as depending on the nature of the property it may or may not make sense to set a value in a specific method.
If the request is a postback, the values of the controls have not yet
been restored from view state. If you set a control property at this
stage, its value might be overwritten in the next event.
Might is the keyword here. If you consider some properties that may change as a form goes through various states then this is where you have to be careful of what may get overwritten as well as the question of whether or not this is a bad thing as it may be that the updated value should persistent and in other cases the original value may be better such as if someone wants to reset the form to its initial state.
My suggestion would be to do some trial and error to see what works as I can remember working with dynamic controls that could be tricky in some me cases to manage properly.

User control in windows forms application

I have a simple user control with a text box and label in it. I created public properties to access the text in the textbox when I use the user control in another form.
My problem is the property is returning null value when I call it in the form. Am i missing anything?
My property is as follows::
public partial class UserControl1 : UserControl
{
public UserControl1()
{
InitializeComponent();
}
public string rtnTxtMake
{
get
{
return txtMake.Text;
}
set
{
txtMake.Text = value;
}
}
}
and in the next forms button click event i call the property as follows
UserControl1 Usc = new UserControl1();
string Make = Usc.rtnTxtMake;
MessageBox.Show(Make)
UserControl1 Usc = new UserControl1();
string Make = Usc.rtnTxtMake;
If your user control has by default an empty textbox field, then it seems correct that the above two lines of code would return either null or String.Empty (check via String.IsNullOrEmpty), since you explicitly create a new instance of your user control.
I suppose what you really want is this:
You have inserted a user control into a form in the Designer. Let's call this user control instance ctlUser.
You have a button with a Click event handler. The last few lines of code in your question are from that handler method.
In the handler, you wouldn't create a new instance of your user control (Usc) but refer to the one that you previously inserted into your form, ctlUser. Then things should work as expected.
Your UserControl must be added to the Controls collection of a parent Form/Control before it can be properly initialized. Normally you would not write the code yourself that creates and adds the UserControl.
Instead, first build your project, then go to the Deisgner view of your main form and look at the Toolbox.
Your UserControl name (and an icon) should appear towards the top of the toolbox, and you can simply drag it to the main form. The Windows Forms designer will automatically generate the needed initialization code for you.
You should not create a new instance of your control in your button click event handler. Using the Designer approach to create your control you can simply access the existing instance of your control as follows:
public void button_Click(object sender, EventArgs e)
{
// myUserControl1 has already been created and initialized by the Deisgner generated code
// Note the name 'myUserControl1' is just an example, yours may be different.
string controlText=myUserControl1.rtnTxtMake;
// Or to change the UserControl textbox value
myUserControl1.rtnTxtMake="Testing";
}
What exactly to you mean when you say that the property is returning a null value? Is it actually null, or is your MessageBox simple showing empty?
I quickly duplicated your code and it behaves exactly as expected - the MessageBox shows, but it is empty because the default value of the Text property of the TextBox control is an empty string.
Also, the way you are approaching this is a little unusual.
Firstly, the line:
UserControl1 Usc = new UserControl1();
You do not generally need to instantiate a user control like this. Instead you can drag the control from the toolbox onto the design surface of your form. This will then take care of instantiating and initialising your control for you.
I think that this is actually your problem - when you include the line of code above, you are creating a new instance of the user control, and this is is no way realted to the user control that you have dragged onto the designer.
If you go to the designer view of your form and click on the user control, you should see a properties window somehere. If you do no, then either select it from the View menu, or press F4. In the list of properties, there should be one "Name" this is the programatic name generated for your user control. You can change this here if you want, but when you refer to this control in the rest of the form, this is what you must use.
Secondly, the next two lines:
string Make = Usc.rtnTxtMake;
MessageBox.Show(Make)
You can access the property rtnTxtMake directly. Unless you later need to access the Make string in the rest of your code, then directly accessing the property would usually be considered better style.
MessageBox.Show(userControl.rtnTxtMake);

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