using System;
using System.Web.UI.WebControls;
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
for (int i = 0; i < 20; i++)
{
Button bt = new Button();
bt.Text = ""+i;
bt.Click += new EventHandler(bt_Click);
Panel1.Controls.Add(bt);
}
}
public void bt_Click(object sender, EventArgs e)
{
Button selected = sender as Button;
Panel1.Visible = false;
Label lbl = new Label();
lbl.Text = "i am lable";
Panel2.Controls.Add(lbl);
for (int i = 1; i < 30; i++)
{
Button pb = new Button();
pb.Text = selected.Text;
pb.Click += new EventHandler(pb_Click);
Panel2.Controls.Add(pb);
}
}
public void pb_Click(object sender, EventArgs e) // how to trigger it
{
Response.Redirect("http://www.google.com");
}
}
this pb_Click is not trigerring; so guys any idea
Obviously pb_Click won't execute. You are adding controls (buttons) into bt_Click handler will be removed on next submit. You must have to use Page_Load event to add controls dynamically.
You may write/design your code like this: (a trick)
protected void Page_Load(object sender, EventArgs e)
{
for (int i = 0; i < 20; i++)
{
Button bt = new Button();
bt.Text = "" + i;
bt.ID = "btn" + i; // Assign unique ID
bt.Click += new EventHandler(bt_Click);
Panel1.Controls.Add(bt);
}
AddButtons();
}
public void bt_Click(object sender, EventArgs e)
{
ViewState["btnId"] = (sender as Button).ID ;
AddButtons();
}
public void AddButtons()
{
if (ViewState["btnId"] == null)
return;
Button selected = Panel1.FindControl(ViewState["btnId"].ToString()) as Button;
Panel1.Visible = false;
Label lbl = new Label();
lbl.Text = "i am lable";
Panel2.Controls.Add(lbl);
for (int i = 1; i < 30; i++)
{
Button pb = new Button();
pb.Text = selected.Text;
pb.Click += new EventHandler(pb_Click);
Panel2.Controls.Add(pb);
}
}
You need to add the button in the page_init method and do not add them in the button click or page_load methods.
Related
I have array of buttons, and array of labels:
Label[] labels = new Label[10];
Button[] but = new Button[10];
While clicking the other button I want to dynamically create new button and new label from the array, i also want the but[i] to change the tex of labels[i]:
private void button1_Click(object sender, EventArgs e)
{
labels[i] = new Label();
labels[i].Location = new System.Drawing.Point(0, 15+a);
labels[i].Parent = panel1;
labels[i].Text = "Sample text";
labels[i].Size = new System.Drawing.Size(155, 51);
labels[i].BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
a = labels[i].Height + labels[i].Top;
but[i] = new Button();
but[i].Text = "-";
but[i].Location = new System.Drawing.Point(0, labels[i].Height + labels[i].Top);
but[i].Parent = panel1;
but[i].Size = new System.Drawing.Size(155, 10);
but[i].Click += new System.EventHandler(but_Click);
i++;
}
private void but[i]_Click(object sender, EventArgs e)
{
labels[i].Text = "Changed Text";
}
But apparently I can't put an array in an event handler, how should I do it then?
One way to do this is to make your method return a handler instead of being a handler:
private EventHandler but_Click(int i)
{
return (s, e) => labels[i].Text = "Changed Text";
}
And use it like:
but[i].Click += but_Click(i);
Or do it inline:
but[i].Click += (s, ea) => labels[i].Text = "Changed Text";
What's happening in either of these is some compiler magic to capture the i variable. It's equivalent to this (which is also a valid, if verbose, way to do it):
class MyWrapper {
private int i;
public MyWrapper(int i) {
this.i = i;
}
public void TheHandler(object sender, EventArgs e) {
// TODO: capture the object that owns `labels` also, or this won't work.
labels[i].Text = "Changed Text";
}
}
//call with
but[i].Click += new EventHandler(new MyWrapper(i).TheHandler);
You could add the array index to the button as Tag property, and then pull it back out in but_Click.
So, add
but[i].Tag = i;
to the button creation. And then change the event handler:
private void but_Click(object sender, EventArgs e)
{
int buttonIndex = (int)((Button)sender).Tag;
labels[buttonIndex].Text = "Changed Text";
}
Or put the event handler inline:
but[i].Click += (s,e) => { label[i].Text = "Changed Text"; }
Or another option using the Tag property, add:
but[i].Tag = label[i];
...
private void but_Click(object sender, EventArgs e)
{
Label label = (Label)((Button)sender).Tag;
label.Text = "Changed Text";
}
Advantage of this approach is you're not relying on keeping arrays in synch after the initial creation of the controls.
I guess this is self-explaining:
public void SomeMehthod()
{
Button btn1 = new Button();
Button btn2 = new Button();
Button btn3 = new Button();
// Your button-array
Button[] btns = new Button[]
{
btn1,
btn2,
btn3
};
foreach(Button btn in btns)
{
// For each button setup the same method to fire on click
btn.Click += new EventHandler(ButtonClicked);
}
}
private void ButtonClicked(Object sender, EventArgs e)
{
// This will fire on any button from the array
// You can switch on the name, or location or anything else
switch((sender as Button).Name)
{
case "btn1":
// Do something
break;
case "btn2":
// Do something
break;
case "btn3":
// Do something
break;
}
}
Or if your array is accessible globaly:
Button[] btns = new Button[5];
Label[] lbls = new Label[5];
private void ButtonClicked(Object sender, EventArgs e)
{
Button clicked = sender as Button;
int indexOfButton = btns.ToList().IndexOf(clicked);
// ..IndexOf() returns -1 if nothign is found
if(indexOfButton > 0)
{
lbls[indexOfButton].DoWhatYouWant...
}
}
i tried to do this(mine field) but i cant visible = false any button when im clicked that.
by the way this.visible = false is going to visible form -.-
private void Form1_Load(object sender, EventArgs e)
{
this.Size = new Size(541, 537);
for (int j = 24; j < ClientSize.Height; j += 25)
{
for (int i = 0; i < ClientSize.Width; i += 25)
{
Button btn = new Button();
btn.Width = 25;
btn.Height = 25;
btn.Location = new Point(i, j);
btn.Click += btn_Click;
Controls.Add(btn);
}
}
}
void btn_Click(object sender, EventArgs e)
{
//When i clicked anyone of them that comes be invisible,
}
thx for helping
The control that fired the event is stored in sender - cast it back to a Button.
void btn_Click(object sender, EventArgs e)
{
var button = (Button)sender;
button.Hide();
}
Alternatively, if that's all you're doing in the event, you could define it in a single line like this:
btn.Click += delegate { btn.Hide(); };
I have a window form where I am creating a list of Checkboxes. The number of checkboxes created are based upon how many items are returned from the database. I've been able to create the checkboxes; however, I am not sure how to add event handlers for these checkboxes. For example, I'd like to add an OnCheckedChanged or CheckStateChanged event. How can I add these events? Also, I would appreciate any other suggestion. I am a total newbie to programming.
private void Form1_Load(object sender, EventArgs e)
{
CheckBoxes = new CheckBox[listGroup.Count()];
for (int i = 0; i < listGroup.Count(); i++)
{
CheckBoxes[i] = new CheckBox();
CheckBoxes[i].Text = listGroup.ElementAt(i).GroupName;
CheckBoxes[i].Name = "txt" + listGroup.ElementAt(i).GroupName.Replace(' ', '_');
CheckBoxes[i].CheckedChanged += new EventHandler(CheckBoxes[i]+"_CheckedChanged");
CheckBoxes[i].Width = 200;
if (i == 0)
{
CheckBoxes[i].Location = new System.Drawing.Point(5, 10);
}
else if (i == 1)
{
CheckBoxes[i].Location = new System.Drawing.Point(5, 40);
}
else if (i == 2)
{
CheckBoxes[i].Location = new System.Drawing.Point(5, 80);
}
this.Controls.Add(CheckBoxes[i]);
}
}
private void Form1_Load(object sender, EventArgs e)
{
//...
CheckBoxes[i].CheckedChanged += checkBoxes_CheckedChanged;
CheckBoxes[i].CheckStateChanged += checkBoxes_CheckStateChanged;
}
void checkBoxes_CheckedChanged(object sender, EventArgs e)
{ //do stuff when checked changed }
void checkBoxes_CheckStateChanged(object sender, EventArgs e)
{ //do stuff when check state changed }
Note: this will give identical event handling for all of your checkboxes.
If you want to do different things for different textboxes, you have to name the eventhandler differently and define that eventhandler.
A more efficient way to set the location of your checkboxes
for (int i = 0; i < listGroup.Count(); i++)
{
CheckBoxes[i] = new CheckBox();
CheckBoxes[i].Text = listGroup.ElementAt(i).GroupName;
CheckBoxes[i].Name = "txt" + listGroup.ElementAt(i).GroupName.Replace(' ', '_');
CheckBoxes[i].CheckedChanged += new EventHandler(CheckBoxes[i] + "_CheckedChanged");
CheckBoxes[i].Width = 200;
//set location based on index of i
CheckBoxes[i].Location = new System.Drawing.Point(5, 10 + (i * 30));
this.Controls.Add(CheckBoxes[i]);
}
private void LoadNewCheckboxes()
{
dynamic listGroupCount = 10;
List<System.Windows.Forms.CheckBox> CheckBoxes = new List<System.Windows.Forms.CheckBox>();
for (int i = 0; i <= listGroupCount - 1; i++)
{
System.Windows.Forms.CheckBox chkbox = new System.Windows.Forms.CheckBox();
chkbox.Text = i.ToString();
//listGroup.ElementAt(i).GroupName
chkbox.Name = "txt" + i.ToString();
//listGroup.ElementAt(i).GroupName.Replace(" "c, "_"c)
chkbox.CheckedChanged += new EventHandler(chkbox_CheckedChanged);
chkbox.CheckStateChanged += new EventHandler(chkbox_CheckStateChanged);
chkbox.Width = 200;
chkbox.AutoSize = true;
this.Controls.Add(chkbox);
CheckBoxes.Add(chkbox);
if (i == 0)
{
chkbox.Location = new System.Drawing.Point(5, 10);
}
else
{
chkbox.Location = new System.Drawing.Point(5, (CheckBoxes[i - 1].Top + CheckBoxes[i - 1].Height + 10));
}
}
}
private void chkbox_CheckedChanged(object sender, EventArgs e)
{
System.Windows.Forms.CheckBox chkbox = (System.Windows.Forms.CheckBox)sender;
if (chkbox != null)
{
//do somthing
Debug.WriteLine("chkbox_CheckedChanged");
Debug.WriteLine(chkbox.Text);
Debug.WriteLine(chkbox.Checked.ToString());
Debug.WriteLine(chkbox.Name.ToString());
}
}
private void chkbox_CheckStateChanged(object sender, EventArgs e)
{
System.Windows.Forms.CheckBox chkbox = (System.Windows.Forms.CheckBox)sender;
if (chkbox != null)
{
//do somthing
Debug.WriteLine("chkbox_CheckStateChanged");
Debug.WriteLine(chkbox.Text);
Debug.WriteLine(chkbox.Checked.ToString());
Debug.WriteLine(chkbox.Name.ToString());
}
}
I have tried creating textboxes dynamically using lists. All i need now is, how can i reset all text boxes that i have created by hitting a reset button.
The following is my code:
public void button2_Click_1(object sender, EventArgs e)
{
int number = Convert.ToInt32(textBox2.Text);
List<TextBox> inputTextBoxes;
inputTextBoxes = new List<TextBox>();
for (int i = 1; i <= number; i++)
{
Label labelInput = new Label();
TextBox textBoxNewInput = new TextBox();
labelInput.Text = "Activity No: " + i;
labelInput.Location = new System.Drawing.Point(30, textBox2.Bottom + (i * 40));
labelInput.AutoSize = true;
textBoxNewInput.Location = new System.Drawing.Point(labelInput.Width+60, labelInput.Top - 3);
inputTextBoxes.Add(textBoxNewInput);
this.Controls.Add(labelInput);
this.Controls.Add(textBoxNewInput);
}
}
The answer is:
private void resetButton_Click(object sender,EventArgs e)
{
for (int i = 0; i <= inputTextBoxes.Length; i++)
{
inputTextBoxes[i].Text = "";
}
}
And you should declare inputTextBoxes is a class member which is same class' of buttons.
Move the following line outside the event handler function (outside the function but inside the class)
List<TextBox> inputTextBoxes;
Then on the reset button click
private void btnReset_Click(object sender, EventArgs e)
{
foreach(TextBox txt in inputTextBoxes)
{
this.Controls.Remove(txt);
}
inputTextBoxes.Clear();
}
Edit: Corrected the class type in foreach loop (from Button to TextBox)
I have created a number of silverlight buttons thus:-
string b = "Button";
for (int i = 0; i < 10; i++)
{
Button btn = new Button();
btn.Name = b+i.ToString();
btn.FontSize += 2;
btn.Content = "Click Me " ;
btn.Click += new RoutedEventHandler(btn_Click);
stack.Children.Add(btn);
}
LayoutRoot.Children.Add(stack);
In the button click event I want to get the name of the button that was pressed. I had hoped that
string snd = sender.ToString(); would yield the information but all it gives is System.Windows.Controls.Button. Can anyone please help. Thanks.
You need to cast sender to a button.
public void btn_Click(object sender, EventArgs e)
{
var btn = (Button)sender;
Console.WriteLine(btn.Name);
}
public void btn_Click(object sender, EventArgs e)
{
var b = sender as Button;
if (b != null)
{
var name = b.Name;
// do something with name
}
}
Try this:
(sender as Button).Name
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