I have a problem I've been looking into for a few days now, I just can't think of a logical way of doing what I want.
I have an app which has a task list. It starts of with 3 controls: a textbox, datetimepicker and a PictureBox which changes image on click. The user can then press an image which will add another row of controls below (It gets the properties of the dynamic controls from the controls already created):
https://www.dropbox.com/s/o2pub6orww24w25/tasklist.png (This is a screenshot to make it clearer)
Now what I want to do is save the values from each of the rows (A row being defined as: Textbox, Date, Status) into an SQLite DB.
For the first row it is easy, because that has a unique design name (and is a 'static' control).
However, the problem hits when I attempt to save values from the dynamic controls:
Problem a) I cannot reference the dynamic control because 'It does not Exist in the current Context'. -The function for creating the controls has a public access modifier so I thought that should do the trick? -It didn't. I've also tried:Panel1.pb.blah but it still didn't recognize the control?
Problem b) How can I tell my program that each row is a new set of data? In other words, how can I run a new insert command for each row? -I thought of doing this as a for-each-textbox loop, however would that not just pick up the first dynamic date everytime?
I've also thought of using the tag property and setting it to the counter variable, to group the controls in the row. (The counter being an integer which increments every time a new row is added.) However I cannot do that because the picture box uses the tag property as part of its function to change image on click (Changes multiple times).
Code:
Adding the Controls:
public void pictureBox1_Click(object sender, EventArgs e)
{
//TextBox Control
int tbh = tasktb.Location.Y + (counter*25);
int tbsh = tasktb.Size.Height;
int tbsw = tasktb.Size.Width;
TextBox tb = new TextBox();
tb.Location = new Point(9, tbh);
tb.Size = new System.Drawing.Size(tbsw, tbsh);
tb.Tag = counter.ToString();
//Date Time Control
int dth = duedatedb.Location.Y + (counter * 25);
int dtsh = duedatedb.Size.Height;
int dtsw = duedatedb.Size.Width;
DateTimePicker dtp = new DateTimePicker();
dtp.Location = new Point(300, dth);
dtp.Size = new Size(dtsw, dtsh);
dtp.Format = System.Windows.Forms.DateTimePickerFormat.Short;
//Picture Box Control
int stsh = status.Location.Y + (counter * 25);
int stssh = status.Size.Height;
int stssw = status.Size.Width;
PictureBox pb = new PictureBox();
pb.Location = new Point(429, stsh);
pb.Size = new Size(stssw, stssh);
pb.Image = Red;
pb.Click += new System.EventHandler(pb_Click);
panel1.Controls.Add(tb);
panel1.Controls.Add(dtp);
panel1.Controls.Add(pb);
++counter;
}
Trying to Reference the control: (For purposes of changing the image on click) [Found the Control.Find function from researching this in the MSDN Website]
public void pb_Click(object sender, EventArgs e)
{
PictureBox pb = (panel1.Controls.Find("pb",false));
if (pb.Image == Red) { pb.Image = Orange; status.Tag = "Orange"; }
else if (pb.Image == Orange) { pb.Image = green; status.Tag = "Green"; }
else if (pb.Image == green) { pb.Image = Red; status.Tag = "Red"; }
}
The essential problem here is Problem a, if you guys could see where I have gone wrong with that, I'd be able to go away and attempt to write some code to get around problem b.
(I have included Problem b in this for your suggestions on the best way to do this. -At the moment I have no clue!)
Thank you for any help received! It really is appreciated!
ControlCollection.Find looks for a control with the specified name, and you haven't set any. The variable names in your code aren't related. So, either:
pb.Name = "pb";
But that would mean you'd eventually have several items with the same name. So, seeing how you want to change the picture of the clicked PictureBox, just do this:
public void pb_Click(object sender, EventArgs e)
{
PictureBox pb = (PictureBox)sender;
if (pb.Image == Red) { pb.Image = Orange; status.Tag = "Orange"; }
else if (pb.Image == Orange) { pb.Image = green; status.Tag = "Green"; }
else if (pb.Image == green) { pb.Image = Red; status.Tag = "Red"; }
}
The sender argument always contains a reference to whichever control raised the event, in this case whichever picturebox was clicked!
Edit: As for your other question, I assume you'll need to do stuff to the controls later on, so I suggest you store a reference to all of them (or at least the ones you need), something like this:
// helper class
private class Entry
{
public TextBox TextBox { get; private set; }
public DateTimePicker DateTimePicker { get; private set; }
public PictureBox PictureBox { get; private set; }
public Entry( TextBox tb, DateTimePicker dtp, PictureBox pb )
{
this.TextBox = tb;
this.DateTimePicker = dtp;
this.PictureBox = pb;
}
}
// member field
private List<Entry> m_Entries = new List<Entry>();
// at the end of pictureBox1_Click
public void pictureBox1_Click(object sender, EventArgs e)
{
....
m_Entries.Add( new Entry( tb, dtp, pb ) );
}
Then you can use the items in that list to interact with your rows. You might also want to add an index, or a reference to whatever the original data structure is. Also, you might want to think about if you really should be creating the controls yourself like that or actually use some kind of table/grid control to host them!
Or perhaps just wrap up all those controls in a single UserControl, with logic included and all!
Related
I want to put a cell in every row I have. If a cell that contains an invoice is open, I want to display a certain picture and if it is closed, I want to display another picture in that cell.
Error picture:
Code:
this.dgvBills.DataSource = bill.SearchBills(txtSearch.Text, coBoxState.Text);
DataGridViewImageColumn img = new DataGridViewImageColumn();
img.Name = "img";
img.HeaderText = "Image Column";
img.ValuesAreIcons = true;
dgvBills.Columns.Add(img);
int number_of_rows = dgvBills.RowCount;
for (int i = 0; i < number_of_rows; i++)
{
if (dgvBills.Rows[i].Cells[11].Value.ToString() == "open")
{
dgvBills.Rows[i].Cells["img"].Value = pbox.Image;
}
else
{
dgvBills.Rows[i].Cells["img"].Value = pbox.InitialImage;
}
There are several approaches to this. For a purely visual indicator like this icon, you may be better off displaying the icon during cell formatting.
Handle the DataGridView's CellFormatting event-
private void dgvBills_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
{
switch (dgvBills.Columns[e.ColumnIndex].Name)
{
case "img": // The name of your image column
if (dgvBills.Rows[e.RowIndex].Cells[11].Value.ToString() == "open")
e.Value = pbox.Image; // image stored in a PictureBox
else
e.Value = pbox.InitialImage; // image stored in a PictureBox
break;
}
}
You can clean this up further by changing your image source. Ditch the PictureBox, and use your project Resources. As an example, if you created two 16x16 PNG icons to represent open and closed states, you can add them to your project Resources as open_invoice and closed_invoice.
Then the value assignments become more readable in your code-
e.Value = new Bitmap(Properties.Resources.open_invoice);
e.Value = new Bitmap(Properties.Resources.closed_invoice);
Or if you need to set a "blank" icon-
e.Value = new Bitmap(1, 1);
If you have control over your Data Source, you can tidy this even further. Let suppose that your bill.SearchBills() function returns List<Bill>. Then you can design your Bills class to return a Bitmap directly as a class Property.
public class Bill
{
public Image OpenClosedIcon
{
get
{
return IsOpen
? new Bitmap(Properties.Resources.open_invoice)
: new Bitmap(Properties.Resources.closed_invoice);
}
}
public bool IsOpen
{
get;
set;
}
// The rest of your Bill class definition...
}
The advantage of this is data binding. When the data source provides it, the DataGridView can recognize the Bitmap field and render it correctly in a DataGridViewImageColumn, without additional work from you.
The easiest approach is usually to use the DataGridView's built-in column designer, and create the columns you want. For your DataGridViewImageColumn, set the DataPropertyName to your class field name OpenClosedIcon
With a fully-prepared data source, you likely won't need the CellFormatting handler at all.
I have an array of button created dynamically, suppose 8 buttons, what I want is that when I click a particular button its background picture is changed and the name of button is stored in a linked list. When I click the same button again the background picture goes back to the original and the button name is deleted from linked list. Now I am able to do the first part, the second click is not working as I want it to.
Basically it's a datastructures project (shopping store) therefore I am using linked list, I have a linked list whose content is displayed through picture boxes[] and labels. Here what i am trying to do is when I click the picture box, the content of that particular node is added to a new linked list (added to the cart) and when I click on the picturebox again that particular item is deleted from the linked list (removed from the cart). Clicking it for the first time it is doing what i want it to do but the second click is not really working.
It's a datastructures project therefore I can't really use any built in classes for linked list, I had to write all methods myself and I did and they work.
cb[i].Click += (sender, e)=>{
if (flag == 0) {
// Console.WriteLine(obj.Retrieve(index).NodeContent);
// Console.WriteLine(obj.Retrieve(index).number);
inv.Add(obj.Retrieve(index).NodeContent, obj.Retrieve(index).number);
bill += Convert.ToInt32(obj.Retrieve(index).number);
cb[index].Image = Image.FromFile(#"F:\uni work\3rd semester\project images\rcart.jpg");
flag++;
}
else if (flag == 1)
{
// Console.WriteLine(bill);
bill -= Convert.ToInt32(obj.Retrieve(index).number);
// Console.WriteLine(bill);
inv.Delete(index);
cb[index].Image = Image.FromFile(#"F:\uni work\3rd semester\project images\cart.png");
flag--;
}
Since you are using a LinkedList it does have a Contains Method and a Remove Method that take a string. You haven't specified exactly what your problem is this should work. When you assign images to a control you loose the information that tells you what Image it is.
public partial class Form1 : Form
{
LinkedList<String> myList = new LinkedList<String>();
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
for (int i = 0; i < 8; i++)
{
Button b = new Button() { Height = 30, Width = 70, Location = new Point(i, 50 * i),Name = "NewButton" + (i + 1).ToString() , Tag=i};
b.Click += b_Click;
this.Controls.Add(b);
}
}
void b_Click(object sender, EventArgs e)
{
Button b = (Button)sender;
if(myList.Contains(b.Name)) //Check if button is in the List then Change Picture and remove
{
b.BackgroundImage = Properties.Resources.Peg_Blue;
myList.Remove(b.Name);
}
else
{
b.BackgroundImage = Properties.Resources.Peg_Red;
myList.AddLast(b.Name);
}
}
}
Why not create a class for each button, containing the two images and switch between them on each click?
When I add item(s) to the ListView in any other than LargeIcon view mode, the ListView stops showing the images from LargeImageList when it is switched back to LargeIcon. This situation lasts until new item is added to the ListView in the LargeIcon mode.
So the following sequence illustrates the problem:
create ListView, add column, set View to Details
create ImageList, set ImageSize, assign it to ListView.LargeImageList
create new ListViewItem, set its ImageKey
create new image, add it to the ImageList with given key
add the ListViewItem to the ListView
switch the ListView mode to LargeIcon
no images are shown
repeat steps #3 - #6, now in the LargeIcon mode
all images are shown as expected
What is the point I am still missing?
I have tried following:
Invalidate the ListView
Re-assign the LargeImageList before/after adding the item (even through null)
The test code for those who like it more than words:
public partial class Form1 : Form
{
int counter = 0;
ImageList iList = new ImageList();
private string GetNewKey()
{
return counter++.ToString();
}
private Image GetNewImage(Size size)
{
var bmp = new Bitmap(size.Width, size.Height);
using (var gra = Graphics.FromImage(bmp))
{
var rnd = new Random();
var lines = rnd.Next(1000);
for (int l = 0; l < lines; ++l)
{
var pen = new Pen(Color.FromArgb(rnd.Next(256), rnd.Next(256), rnd.Next(256)));
var p1 = new Point(rnd.Next(size.Width), rnd.Next(size.Height));
var p2 = new Point(rnd.Next(size.Width), rnd.Next(size.Height));
gra.DrawLine(pen, p1, p2);
}
}
return bmp;
}
public Form1()
{
InitializeComponent();
iList.ImageSize = new Size(100, 100);
listView.LargeImageList = iList;
listView.Columns.Add("name");
}
private void buttonAdd_Click(object sender, EventArgs e)
{
var key = GetNewKey();
var lvi = new ListViewItem()
{
Name = key,
Text = "blabla",
ImageKey = key,
};
iList.Images.Add(key, GetNewImage(new Size(100, 100)));
listView.Items.Add(lvi);
}
private void buttonClear_Click(object sender, EventArgs e)
{
listView.Items.Clear();
}
private void buttonLarge_Click(object sender, EventArgs e)
{
listView.View = View.LargeIcon;
}
private void buttonDetails_Click(object sender, EventArgs e)
{
listView.View = View.Details;
}
}
EDIT:
For anyone who would suffer the same problem. After some experiments, there is at least stupid poor man's workaround:
Modify the ImageList, the ListView somehow detects its change and reloads the images for LargeIcon mode. The questions are how it detects the change and why does it ignore the ImageList after mode change...
private void FixIt()
{
// Trigger a reload of the ListView.LargeImageList
if (listView.View == View.LargeIcon)
{
var key = "Dummy image to be deleted right after its insertion...";
iList.Images.Add(key, new Bitmap(1, 1));
iList.Images.RemoveByKey(key);
}
}
EDIT #2:
I have also discovered some other funny features the ListView and associated components have. You might want to check them in answers of question 4097912 and question 23059678
To solve your problem
You could avoid this by useing ImageIndex instead of ImageKey to connect your ListView with the ImageList. So in your buttonAdd_Click event use:
var lvi = new ListViewItem()
{
Name = key,
Text = "blabla",
//ImageKey = key,
//Use ImageIndex and don't set both
ImageIndex= Convert.ToInt32(key) //you could just use count++
};
The reason behind this problem:
The reason behind this is not clear to me, but I assume this may be a bug that when changing from Details to LargeIcon, it only checks ImageIndex in default and if you set ImageKey the ImageIndex will be set to -1. Or may be this is by design, I don't know (see ImageKey section below), since you don't have a SmallImageList, so when changing to LargeIcon view, ImageIndex is null or -1 and the ImageKey is ignored.
About ListViewItem.ImageIndex Property
The ImageKey and ImageIndex properties are mutually exclusive, meaning if one is set, the other is ignored. Furthermore, if you set the ImageKey property, the ImageIndex property is automatically set to -1. Alternatively, if you set the ImageIndex property, the ImageKey is automatically set to an empty string ("").
About ListViewItem.ImageKey Property
If you are using multiple image lists, for small and large icon view, with a ListView control, you should place small and large versions of the image at the same index location in their respective image lists. When switching between views, the index location of the image in one list is used to locate the image in the other list, regardless of the key value specified.
And this can somehow be verified:
using your existing code (use ImageKey)
set ImageIndex for any Item in your listView within the buttonLarge_Click event handler will show you that item's image.
set ImageKey for any Item within the buttonLarge_Click event handler will not show that itme's image.
e.g.:
private void buttonLarge_Click(object sender, EventArgs e)
{
listView.View = View.LargeIcon;
//Set ImageIndex of Item 0 you could see its Icon.
listView.Items[0].ImageIndex= 0 ;
//set ImageKey will change nothing
//listView.Items[0].ImageKey= "0" ;
}
I have made a voting system for our school. I already made an Add, Update, Delete, and retrieving data from database. I have a problem making a dynamic control automatically with the exact amount of data i have in database. For example, I have added pictures to the two Candidates in the position of President, then, I want it to dynamically create a PictureBox in my new form and retrieve the pictures in a 2 pictureboxes and radiobutton for their names under it. Is it possible for me to do it in array? I'm new to programming so bear with me please.
I'm a little bit confused. Can you make an example of it, if possible please.. :)
This should get you going.
Add this code to your form. And you can use this code for any buttons or anything you want. But you should maybe read up on the FlowLayoutPanel or GroupBox to get this to work in reality.
Point _imagePos = new Point(10,10);
int _imageCounter = 1;
private void NewPictureBox(string pathToImg, string imageName)
{
var img = new PictureBox
{
Name = "imageBox" + _imageCounter,
ImageLocation = pathToImg,
Left = _imagePos.X,
Top = _imagePos.Y,
SizeMode = PictureBoxSizeMode.StretchImage,
Height = 50,
Width = 50
};
var txt = new TextBox
{
Text = imageName,
Left = _imagePos.X,
Top = img.Bottom + 10
};
this.Controls.Add(img);
this.Controls.Add(txt);
_imageCounter++;
_imagePos.Y += 10 + img.Height + txt.Height;
}
private void Form1_Load(object sender, EventArgs e)
{
NewPictureBox(#"C:\test\QuestionMark.jpg", "image1");
NewPictureBox(#"C:\test\QuestionMark.jpg", "image2");
}
I am creating an application where a user will input grades and the program will output the weighted average. On load, it will ask for the number of categories for the assignments. The program will then dynamically create textboxes for the user to input information. The problem is that I can not figure out how to read the text that is inputed after I create the textboxes. Here is my code:
TextBox txtbx = new TextBox();
txtbx.Text = "";
txtbx.Name = "txtbx1";
txtbx.Location = new Point(10, 10);
txtbx.Height = 20;
txtbx.Width = 50;
Controls.Add(txtbx);
How can I change this code so I can find the current text in the box when the user submits?
If you are dynamically generating controls then obviously you won't be able to have a field for each one. But if you are trying to access the Controls collection for a named control, the ControlCollection can be indexed by name. After adding the text box with the specified name, you can simply do:
TextBox txtbx = (TextBox)Controls["txtbx1"];
You could use the FindControl method of the Page class.
This method takes a parameter which is the TextBox's ID, which you have to set upon creation:
txtbx.ID = "txtbx1";
Then you can select it:
TextBox txtbx1 = (TextBox)FindControl("txtbx1");
and use it.
Edit: Since the initial question added that he is refering to Windows Forms, my reply above is off-topic.
In Windows Forms, you should simply use a class member variable instead of a local variable. E.g.:
public partial class MyForm
{
...
private TextBox txtbx;
...
private void createControls()
{
txtbx = new TextBox();
txtbx.Text = "";
txtbx.Name = "txtbx1";
txtbx.Location = new Point(10, 10);
txtbx.Height = 20;
txtbx.Width = 50;
Controls.Add(txtbx);
}
private void someOtherFunction()
{
// Do something other with the created text box.
txtbx.Text = "abc";
}
}
This code for the Dynamically Add Textbox On Button Click
int count = 1;
public System.Windows.Forms.TextBox AddNewTextBox()
{
System.Windows.Forms.TextBox txt = new System.Windows.Forms.TextBox();
this.Controls.Add(txt);
txt.Top = count * 25;
txt.Left = 100;
txt.Text = "TextBox " + this.count.ToString();
count = count + 1;
return txt;
}
private void Onbutton_Click(object sender, EventArgs e)
{
//Call the method AddNewTextBox that uses for Dynamically create Textbox
AddNewTextBox();
}
I hope this code will help you .
Thank You
Happy Coding:)
Keep a list of references of all text boxes on the form. Add the textBox reference to the list when you create them dynamically.
Then you can simply iterate through all text boxes in the list when you want to read their text.
Make sure that you name the text boxes as per their related category names. Then you can also Find the control in the list by their names.
class MyForm : Form
{
IList<TextBox> _textBoxes = new List<TextBox>();
private void AddTextBox(string categoryName){
var myTextBox = new TextBox();
myTextBox .Name = categoryName + "txtbx";
// set other properties and add to Form.Controls collection
_textBoxes.Add(myTextBox);
}
private TextBox FindTextBox(string categoryName)
{
return _textBoxes.Where( t => t.Name.StartsWith(categoryName)).FirstOrDefault();
}
}
All you need to do is set up an OnClick listener for your submit button and have it do something like this
private void OnSubmit(object sender, EventArgs args)
{
string yourText = txtbx.Text;
}
You'll have to keep a reference to the text box after you create it. yourText will contain the value you need. Hope this helps