Dynamic events in code - c#

I have a radio buttons and one text box on a panel made dynamically . Now, I want to disable the text box when the second radio button is checked, means they are both connected. how can I make the event for it. I want to have the event working.
Thanks a lot in advanced.
this is my code which is not working:
Panel pnl = new Panel();
pnl.Name = "pnl_";
pnl.Size = new Size(630, 80);
RadioButton rd = new RadioButton();
rd.Name = "rd_" + dr[i]["Value_Name"].ToString();
rd.Text = dr[i]["Value_Name"].ToString();
rd.Location = new Point(i,i*2);
pnl.Controls.Add(rd);
TextBox txt = new TextBox();
txt.Name = "txt_" + Field_Name+"_"+dr[i]["Value_Name"].ToString();
txt.Size = new Size(171, 20);
txt.Text = Field_Name + "_" + dr[i]["Value_Name"].ToString();
txt.Location = new Point(20, 30);
pnl.Controls.Add(txt);
////// ???? ////////
rd.CheckedChanged += new EventHandler(eventTxt(txt));
void eventTxt(object sender,EventArgs e,TextBox txt)
{
RadioButton rd = (RadioButton)sender;
txt.Enabled = rd.Checked;
}

Use a lambda to close over the relevant variable(s):
rd.CheckedChanged += (s, args) => txt.Enabled = rd.Checked;
If you had more than a one line implementation, you could call out to a method accepting whatever parameters you've closed over, instead of including it all inline.

I would suggest to set the Tag of the radio button and get walk down the dependencies.
rd.Tag = txt;
In the event handler use this:
TextBox txt = (sender as Control).Tag as TextBox;
txt.Enabled = ...

you can use code given
rd.CheckedChanged += (s,argx) => txt.Enabled = rd.Checked;

Here's how you could create an event for it:
//if you are using Microsoft Visual Studio, the following
//line of code will go in a separate file called 'Form1.Design.cs'
//instead of just 'Form1.cs'
myTextBox.CheckChangedEventHandeler += new EventHandeler(checkBox1_CheckChanged); //set an event handeler
public void checkBox1_CheckChanged(object sender, EventArgs e) //what you want to happen every time the check is changed
{
if(checkBox1.checked == true) //replace 'checkBox1' with your check-box's name
{
myTextBox.enabled = false; //replace 'myTextbox' with your text box's name;
//change your text box's enabled property to false
}
}
Hope it helps!

Related

read the texts of run-time added textboxes

I have an application where the user can add any number of tabpages depending on what he/she needs. These tabpages have identical controls (textboxes and labels).
The controls on each tabpages are named like this: (on tabpage1 the controls are named: txtServer1, txtPort1, txtUser1, txtDbName1. if the user clicks the 'add another connection button' the application creates a second tabpage and the controls will be named: txtServer2, txtPort2, txtUser2, txtDbName2) and so on...
for example if the user have multiple tabpages to set-up:
the user clicks the 'add another connection' and the another tabpage with identical controls has been created and the user fills it up with appropriate data:
same thing goes here:
here's the code for dynamically added tabpage with controls:
//when 'add another connection' button is clicked
private void btnAddConnection_Click(object sender, EventArgs e)
{
string tabTitle = "Connection " + (tabControl1.TabCount + 1).ToString();
TabPage tabPage = new TabPage(tabTitle);
tabControl1.TabPages.Add(tabPage);
}
//when another tabpage has been added to tabcontrol
private void tabControl1_ControlAdded(object sender, ControlEventArgs e)
{
//control instances
TextBox txtServer = new TextBox();
TextBox txtPort = new TextBox();
TextBox txtUser = new TextBox();
TextBox txtDbName = new TextBox();
Label lblServer = new Label();
Label lblPort = new Label();
Label lblUser = new Label();
Label lblDbName = new Label();
tabControl1.SelectedTab = tabControl1.TabPages[tabControl1.TabCount - 1]; //select the newly addded tabpage
tabControl1.SelectedTab.BackColor = tabPage1.BackColor; //tabpage background color
//lblServer Properties
lblServer.Location = lblServer1.Location;
lblServer.Text = lblServer1.Text;
lblServer.ForeColor = lblServer1.ForeColor;
lblServer.Name = "lblServer" + tabControl1.TabCount.ToString();
//lblPort Properties
lblPort.Location = lblPort1.Location;
lblPort.Text = lblPort1.Text;
lblPort.ForeColor = lblPort1.ForeColor;
lblPort.Name = "lblPort" + tabControl1.TabCount.ToString();
//lblUser Properties
lblUser.Location = lblUser1.Location;
lblUser.Text = lblUser1.Text;
lblUser.ForeColor = lblUser1.ForeColor;
lblUser.Name = "lblUser" + tabControl1.TabCount.ToString();
//lblDbName Properties
lblDbName.Location = lblDbName1.Location;
lblDbName.Text = lblDbName1.Text;
lblDbName.ForeColor = lblDbName1.ForeColor;
lblDbName.Name = "lblDbName" + tabControl1.TabCount.ToString();
//txtserver properties
txtServer.Location = txtServer1.Location;
txtServer.Width = txtServer1.Width;
txtServer.Height = txtServer1.Height;
txtServer.Font = txtServer1.Font;
txtServer.Name = "txtServer" + tabControl1.TabCount.ToString();
//txtport properties
txtPort.Location = txtPort1.Location;
txtPort.Width = txtPort1.Width;
txtPort.Height = txtPort1.Height;
txtPort.Font = txtPort1.Font;
txtPort.Name = "txtPort" + tabControl1.TabCount.ToString();
//txtuser properties
txtUser.Location = txtUser1.Location;
txtUser.Width = txtUser1.Width;
txtUser.Height = txtUser1.Height;
txtUser.Font = txtUser1.Font;
txtUser.Name = "txtUser" + tabControl1.TabCount.ToString();
//txtdbname properties
txtDbName.Location = txtDbName1.Location;
txtDbName.Width = txtDbName1.Width;
txtDbName.Height = txtDbName1.Height;
txtDbName.Font = txtDbName1.Font;
txtDbName.Name = "txtUser" + tabControl1.TabCount.ToString();
//add controls to tabpage
tabControl1.SelectedTab.Controls.Add(lblServer);
tabControl1.SelectedTab.Controls.Add(lblPort);
tabControl1.SelectedTab.Controls.Add(lblUser);
tabControl1.SelectedTab.Controls.Add(lblDbName);
tabControl1.SelectedTab.Controls.Add(txtServer);
tabControl1.SelectedTab.Controls.Add(txtPort);
tabControl1.SelectedTab.Controls.Add(txtUser);
tabControl1.SelectedTab.Controls.Add(txtDbName);
}
When the user clicks the save button, I want the application to read each text in the textboxes (except for that url text) so that I can save it to a configuration file.
all I can think of is this
private void saveToolStripMenuItem_Click(object sender, EventArgs e)
{
string connection;
for (int i = 1; i <= tabControl1.TabCount; i++ )
{
connection = "server=" + txtServer[i].Text + ";port=" txtPort[i].Text + ";user=" + txtUser[i].Text + ";dbname=" + txtDbName[i];
//save to config file code goes here...
}
}
and I know this is not correct.
any solution for this? thanks :)
This is the simplest way you can try this just use below function to get text from control in tabpage
public string getValue(string controlName, TabPage selectedTab)
{
if (selectedTab.Controls.ContainsKey(controlName)){
TextBox selectedtb = (TextBox)selectedTab.Controls[controlName];
return selectedtb.Text;
}
else
return null;
}
and in your save code use it like below
string connection;
int i = 1;
TabControl.TabPageCollection pages = tabControl1.TabPages;
foreach (TabPage page in pages)
{
connection = "server=" + getValue("txtServer"+i,page) + ";port=" +getValue("txtPort"+i,page) + ";user=" + getValue("txtUser"+i,page) + ";dbname=" + getValue("txtDbName"+i,page);
i++;
//save to config file code goes here...
}
txtServer[i].Text it's true but You have not defined an array.
You can do it like this
//global
List<TextBox> txtServerList= new List<TextBox>();
private void tabControl1_ControlAdded(object sender, ControlEventArgs e)
{
txtServer.Location = txtServer1.Location;
txtServer.Width = txtServer1.Width;
txtServer.Height = txtServer1.Height;
txtServer.Font = txtServer.Font;
txtServer.Name = "txtServer" + tabControl1.TabCount.ToString();
txtServerList.Add(txtServer)
.
.
.
}
Finally
for (int i = 1; i <= tabControl1.TabCount; i++ )
{
connection=txtServerList.get(i).Text + ......
}
You could just loop over the controls and find the matching name, something like this:
foreach(var page in tabControl1.TabPages){
var server = ProcessControls(page.Controls, "txtServer");
//... continue with the others
}
private TextBox ProcessControls(Control ctrlContainer, string name)
{
foreach (Control ctrl in ctrlContainer.Controls)
{
if (ctrl.GetType() == typeof(TextBox))
{
if(ctrl.Name.StartsWith(name))
return (TextBox)ctrl;
}
}
}
You can use an ArrayList to store and access all dynamically added controls. Set a name for each dynamically added controls. It can be based on the size of ArrayList.
I will not show the exact systax of c#.
first
declare an ArrayList or List(Type Safe)
List<Button> buttons = new List<Button>();
We just created a storage for our buttons that will be added at runtime.
void your_event (some parameters) {
Button temp = new Button("Hello");
temp.Name="button_name";
YourMainPanel.Controls.add(temp);
//after creating your button add it to the parent container. of any control where you want this button to be added.
//you can also set the coordinates of the button if you like
//after creating the button we need to add it to our List so that we can
//access it later, since the value of the 'temp' will change after this
//event was invoked in the future.
buttons.add(temp);
}
There are several ways to get the items in List<T>. One is by using index.
void someMethod(some parameters) {
Button button = buttons.ElementAt(index);
}

Passing and Storing Strings

I'm trying to pass some strings(className & classID) and store them in a different variable(classNameClicked & classIDClicked) based on what hyperlink the user clicked.
Here is my code behind(C#) for creating the hyperlinks:
TextBlock txt = new TextBlock();
txt.TextWrapping = TextWrapping.Wrap;
txt.Foreground = Brushes.Black;
txt.FontFamily = new FontFamily("Times New Roman");
txt.FontSize = 25;
txt.Margin = new Thickness(5);
TextBlock ClassID = new TextBlock();
ClassID.Visibility = Visibility.Collapsed;
ClassID.Text = classID;
Run run = new Run(className);
Hyperlink link = new Hyperlink(run);
link.Click += Link_Click;
txt.Inlines.Add(ClassID);
txt.Inlines.Add(link);
myStackPanel.Children.Add(txt);
frame.Content = myStackPanel;
I was able to pass the string from the className to classNameClicked by extracting the text from the hyperlink using the code below:
private void Link_Click(object sender, RoutedEventArgs e)
{
classNameClicked = ((sender as Hyperlink).Inlines.FirstInline as Run).Text;
classIDClicked = (sender as Textblock).Text;
Class_Page class_page = new Class_Page();
NavigationService.Navigate(class_page);
}
However, I cant seem to figure out how to extract the string from classID.
Please help.
You just have to reference the parent of your Hyperlink.
So instead of
classNameClicked = ((sender as Hyperlink).Inlines.FirstInline as Run).Text;
classIDClicked = (sender as TextBlock).Text;
you can write
Hyperlink link = sender as Hyperlink;
classNameClicked = (link.Inlines.FirstInline as Run).Text;
classIDClicked = (link.Parent as TextBlock).Inlines.OfType<Run>().First().Text;
If you don't want to use LINQ you could also write:
classIDClicked = ((link.Parent as TextBlock).Inlines.FirstInline as Run).Text;
But I have the same overall opinion as Mat in the comments. This is really ugly and MVVM would be the way to go for writing much cleaner code.
Additionally you should probably add some null checking too.
Edit as requested in the comment:
If you don't want to display the classID in your GUI then you could hide it in the Tag of the Hyperlink:
Hyperlink link = new Hyperlink(run);
link.Tag = classID;
link.Click += Link_Click;
And then just get it in your Click handler:
classIDClicked = link.Tag as string;
You don't need a hidden TextBlock for that.

Saving User Input in a Dynamically Created Form

I'm trying to get the values that a user inputs in a textbox in a dynamically generated form. Another method loads and parses an XML file and creates an object that has specific getters and setters for the settings that it finds in the file (Server, Port, Title, etc.).
The dynamic form is created using labels and textboxes like this. It was designed only to display the information from the XML file, and I am trying to implement a system that allows users to edit the information before saving it again to the file. I'm doing alright with the methods to save and edit the XML file, but I'm lost for how to associate the input in any given textbox with the associated label representing the key in the XML file to change.
Below is the current form implementation where the labels and textboxes are created as part of a foreach loop. I tried creating textbox.Leave eventHandler to track when the user has finished changing a value, but I can't figure out how to know what label it is associated with.
var sortedSettings = new SortedDictionary<string, string>(theSettings.Settings);
int numSettings = sortedSettings.Count;
TextBox[] txt = new TextBox[numSettings];
Label[] label = new Label[numSettings];
int labelSpacing = this.labelSecond.Top - this.labelTop.Bottom;
int textSpacing = this.textBoxSecond.Top - this.textBoxTop.Bottom;
int line = 0;
foreach (KeyValuePair<string, string> key in sortedSettings)
{
label[line] = new Label();
label[line].Text = key.Key;
label[line].Left = this.labelTop.Left;
label[line].Height = this.labelTop.Height;
label[line].Width = this.labelTop.Width;
txt[line] = new TextBox();
txt[line].Text = key.Value;
txt[line].Left = this.textBoxTop.Left;
txt[line].Height = this.textBoxTop.Height;
txt[line].Width = this.textBoxTop.Width;
txt[line].ReadOnly = false;
// Attach and initialize EventHandler for template textbox on Leave
txt[line].Leave += new System.EventHandler(txt_Leave);
if (line > 0)
{
label[line].Top = label[line - 1].Bottom + labelSpacing;
txt[line].Top = txt[line - 1].Bottom + textSpacing;
}
else
{
label[line].Top = this.labelTop.Top;
txt[line].Top = this.textBoxTop.Top;
}
this.Controls.Add(label[line]);
this.Controls.Add(txt[line]);
line++;
}
private void txt_Leave(object sender, EventArgs e)
{
String enteredVal = sender;
FormUtilities.FindAndCenterMsgBox(this.Bounds, true, "EventChecker");
MessageBox.Show("The current value of LABEL is " + enteredVal, "EventChecker");
}
One option is to use TextBox.Tag property.
Example (in foreach loop):
txt[line] = new TextBox();
txt[line].Text = key.Value;
txt[line].Tag = label[line];
To get label associated with TextBox:
TextBox t = txt[0];
Label l = t.Tag as Label;
//Here is how you identify textbox which generated the event.
private void txt_Leave(object sender, EventArgs e)
{
TextBox tb = sender as TextBox;
//..
}

How to create drop down information box in C# Winforms?

I want to make a button that can drop down a multi-line label or form which contains help documentation for the user.
I have searched and I can't find anything that is for C# Winforms. Do any free controls out there exist for this or will I have to create it myself?
Many thanks,
Richard
Using ToolStripControlHost and ToolStripDropDown controls can provide this for you:
private void button1_Click(object sender, EventArgs e) {
var helpInfo = new StringBuilder();
helpInfo.AppendLine("This is line one.");
helpInfo.AppendLine("This is line two.");
var textHelp = new TextBox() { Multiline = true,
ReadOnly = true,
Text = helpInfo.ToString(),
MinimumSize = new Size(100, 100)
};
var toolHost = new ToolStripControlHost(textHelp);
toolHost.Margin = new Padding(0);
var toolDrop = new ToolStripDropDown();
toolDrop.Padding = new Padding(0);
toolDrop.Items.Add(toolHost);
toolDrop.Show(button1, button1.Width, 0);
}
Result:
I think it will be a bad user experience to see a tooltip on click of a button. However, you can use this if you really want to
var b = new Button();
b.Click += (sender, args) => new ToolTip().Show("Help documentation", b.Parent, new Point(b.Location.X, b.Location.X + 10));

Dynamic control and its Event

We are creating dynamic text boxes and buttons inside a grid for each row. Now we want to create click event for each button. To create button inside the grid in using ITemplate.
Code:
ImageButton imbtnAdd = new ImageButton();
imbtnAdd.ID = "imbtn" + columnName;
imbtnAdd.ImageUrl = "btn_add_icon.gif";
imbtnAdd.Width = 20;
container.Controls.Add(imbtnAdd);
Error:
I have used imbtnAdd.Click += new ImageClickEventHandler(imbtnAdd_Click); but it shows an error message
imbtnAdd_Click does not exist
ImageButton imbtnAdd = new ImageButton();
imbtnAdd.ID = "imbtn" + columnName;
imbtnAdd.ImageUrl = "btn_add_icon.gif";
imbtnAdd.Width = 20;
imbtnAdd.Click += imbtnAdd_Click;
container.Controls.Add(imbtnAdd);
// ...
private void imbtnAdd_Click(object sender, EventArgs e)
{
// handle event
}
Jrista's answer is correct.
Although, if you want to implement different handlers for all the buttons and you are using .Net 3.0 or above, you can use lambdas:
imbtnAdd.Click += (object sender, EventArgs e) =>
{
// Code handling code goes here...
};

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