Develop Reference

Creating an array of pictureboxes in windows form (C#)

I'm trying to create an array/list of picturebox objects that are declared and added to the form on button click (Meaning that I'm not creating multiple objects with my array, but plan to if I can get this to run). Not getting errors, but the pictureboxes themselves do not appear on the form.
private void spawn_Click(object sender, EventArgs e)
{
var pictureTest[0] = new PictureBox();
pictureTest[0].Image = Properties.Resources.testimage;
pictureTest[0].Location = new Point(500, 250);
pictureTest[0].Name = "spawn1";
pictureTest[0].Size = new Size(50, 50);
pictureTest[0].TabIndex = 98;
pictureTest[0].TabStop = false;
this.Controls.Add(pictureTest[0]);
}
Through the course of my research, I've mainly just gotten the advice to use this.Controls.Add, but that doesn't seem to be my issue here. My array is declared earlier with:
PictureBox[] pictureTest = new pictureTest[100];

As #HansPassant says in the comments, this code doesn't compile. The following should broadly do what you want:
int _position = 10;
private void spawn_Click(object sender, EventArgs e)
{
var pictureTest = new PictureBox();
pictureTest.Image = Properties.Resources.testimage;
pictureTest.Location = new Point(_position, 250);
pictureTest.Name = "spawn1";
pictureTest.Size = new Size(50, 50);
pictureTest.TabIndex = 98;
pictureTest.TabStop = false;
this.Controls.Add(pictureTest);
_position += 100;
}
Firstly, there's no need to maintain a separate array of PictureBox, as they are part of your form. Secondly, as #HansPassant said - you were overlaying the images directly on top of each other, so you couldn't tell if you had 1 or 1000.

How to automaticly locate buttons on panel c#

I have a few buttons to add on the form. In the code I'm setting up some button properties:
class DigitButton : Button
{
private static int digitBtnTag;
public DigitButton()
: base()
{
this.Size = new Size(30, 30);
this.Tag = digitBtnTag;
this.Text = (this.Tag).ToString();
this.Margin = new Padding(2);
this.Padding = new Padding(2);
digitBtnTag++;
}
}
In the MainForm.cs I have
for (int i = 0; i < dgtBtns.Length; i++)
{
dgtBtns[i] = new DigitButton();
dgtBtns[i].Click += new EventHandler(this.digitButtonClick);
digitPanel.Controls.Add(dgtBtns[i]);
}
So when I launch a program I see all my buttons in the one place: (0;0) on digitPanel despite property Margin. So why don't all these buttons automaticly "push" each other in the different directions? And how to make it?

Have you tried using a FlowLayout Panel ?
Also, this video might help:
Windows Forms Controls Lesson 5: How to use the FlowLayout Panel

that's not the way controls works in c#. i'm guessing you programed at java a bit because the layout in jave works that whay, but in c# just do
for (int i = 0; i < dgtBtns.Length; i++)
{
dgtBtns[i] = new DigitButton();
dgtBtns[i].Location = new Point(50, 50 * i); // Multiplying by i makes the location shift in every loop
dgtBtns[i].Click += new EventHandler(this.digitButtonClick);
digitPanel.Controls.Add(dgtBtns[i]);
}
you'll have to figure out the location parameters by trying and see

You need to define Left and Top then add the button height or width each time you loop to position your buttons correctly i.e.
int bTop=0;
int bLeft=0;
for (int i = 0; i < dgtBtns.Length; i++)
{
dgtBtns[i] = new DigitButton();
dgtBtns[i].Click += new EventHandler(this.digitButtonClick);
dgtBtns[i].Top = bTop;
bTop += dgtBtns[i].Height;
digitPanel.Controls.Add(dgtBtns[i]);
}

New window replicates

I am working on an interface that uses a Wcf to obtain data from out database, I am having the following issue, I am using a dynamic window to display information as well as some buttons for date times, and close, etc...
However when I close the window and reopen it, it adds everything back to the form that was already there, which creates double and is causing some problems, any advice would be great, thanks in advance
Here is some code to better describe what I have....
This is the button I have on my primary form, which creates the new window
private void butMoreInf_Click(object sender, RoutedEventArgs e)
{
winMain.DataContext = null;
winMainContainer.DataContext = null;
winMainContainerLeft.DataContext = null;
winMainContainerRight.DataContext = null;
datGrid.DataContext = null;
//Generate the new window and panel to go within the window
winMain.Height = 750;
winMain.Width = 950;
winMainContainer.Width = 1000;
winMainContainer.HorizontalAlignment = HorizontalAlignment.Left;
winMainContainerLeft.Width = 120;
winMainContainerLeft.HorizontalAlignment = HorizontalAlignment.Left;
winMainContainerRight.Width = 880;
winMainContainerRight.HorizontalAlignment = HorizontalAlignment.Left;
//Generate the datagrid to contain the date to be changed etc.
datGrid.Margin = new Thickness(0, 12, 12, 12);
datGrid.HorizontalAlignment = HorizontalAlignment.Right;
//Generate a datepicker (start) and label
Label labS = new Label();
labS.Content = "Pick a start date";
labS.Width = 100;
labS.Margin = new Thickness(12, 1, 0, 1);
labS.HorizontalAlignment = HorizontalAlignment.Left;
DatePicker datPickStart = new DatePicker();
datPickStart.Width = 100;
datPickStart.Margin = new Thickness(12, 12, 1, 0);
datPickStart.HorizontalAlignment = HorizontalAlignment.Left;
datPickStart.SelectedDate = DateTime.Now.AddDays(-7);
datStartPick = datPickStart.SelectedDate == null ? DateTime.Now : Convert.ToDateTime(datPickStart.SelectedDate);
//Generate a datepicker (end) and label
Label labE = new Label();
labE.Content = "Pick an end date";
labE.Width = 100;
labE.Margin = new Thickness(12, 1, 0, 1);
labE.HorizontalAlignment = HorizontalAlignment.Left;
DatePicker datPickEnd = new DatePicker();
datPickEnd.Width = 100;
datPickEnd.Margin = new Thickness(12, 12, 1, 0);
datPickEnd.HorizontalAlignment = HorizontalAlignment.Left;
datPickEnd.SelectedDate = DateTime.Now;
datEndPick = datPickEnd.SelectedDate == null ? DateTime.Now : Convert.ToDateTime(datPickEnd.SelectedDate);
//Generate dropdown and label for that box
Label labY = new Label();
labY.Content = "";
labY.Width = 100;
labY.Margin = new Thickness(12, 1, 0, 1);
labY.HorizontalAlignment = HorizontalAlignment.Left;
ComboBox txtY = new ComboBox();
txtY.Width = 100;
txtY.Margin = new Thickness(12, 12, 1, 0);
txtY.HorizontalAlignment = HorizontalAlignment.Left;
txtY.SelectedIndex = 0;
txtY.SelectionChanged += CLLoadErrors;
txtY.SelectedIndex = 0;
//Generate error list button
Button butError = new Button();
butError.Width = 100;
butError.Margin = new Thickness(12, 12, 1, 0);
butError.HorizontalAlignment = HorizontalAlignment.Left;
butError.Content = "Get Errors";
butError.Click += CLLoadErrors;
//Generate clear button
Button butClear = new Button();
butClear.Width = 100;
butClear.Margin = new Thickness(12, 12, 1, 0);
butClear.HorizontalAlignment = HorizontalAlignment.Left;
butClear.Content = "Clear Grid";
butClear.Click += clearDataGrid;
//Generate close button
Button butClose = new Button();
butClose.Width = 100;
butClose.Margin = new Thickness(12, 12, 1, 0);
butClose.HorizontalAlignment = HorizontalAlignment.Left;
butClose.Content = "Close";
butClose.Click += CLHide;
//Add elements to the stackpanel / Also updates them before each instance
winMainContainerLeft.UpdateLayout();
winMainContainerLeft.Children.Add(labS);
winMainContainerLeft.Children.Add(datPickStart);
winMainContainerLeft.Children.Add(labE);
winMainContainerLeft.Children.Add(datPickEnd);
winMainContainerLeft.Children.Add(labY);
winMainContainerLeft.Children.Add(txtY);
winMainContainerLeft.Children.Add(butError);
winMainContainerLeft.Children.Add(butClear);
winMainContainerLeft.Children.Add(butClose);
winMainContainerRight.UpdateLayout();
winMainContainerRight.Children.Remove(datGrid);
winMainContainerRight.Children.Add(datGrid);
winMainContainer.UpdateLayout();
winMainContainer.Orientation = Orientation.Horizontal;
winMainContainer.Children.Remove(winMainContainerLeft);
winMainContainer.Children.Add(winMainContainerLeft);
winMainContainer.Children.Remove(winMainContainerRight);
winMainContainer.Children.Add(winMainContainerRight);
winMain.ResizeMode = ResizeMode.NoResize;
//Display the new form
winMain.UpdateLayout();
winMain.Content = winMainContainer;
winMain.Show();
datGrid.MouseDoubleClick += datGridDClick;
txtY.SelectionChanged += new SelectionChangedEventHandler(txtY_SelectionChanged);
}
Will provide more code if needed.

You are reusing the same window again and again (why?), so you need to clear out the children collections before you add new elements, otherwise every click on your button will show the window + every control you add, resulting in double/triple/... controls.
Update: I assume you use StackPanels (from your comment / having Children enumerations). The Children enumeration is a UIElementCollection which allows to invoke the Clear method. Just call this prior to adding new controls. (on winMainContainer, winMainContainerRight and winMainContainerLeft)

Where do you initialize winMain? Is it a static variable or does it live within your current form?
I'm guessing that you keep adding controls to an existing object(which causes the duplication effect). To fix this you could either reinitialize the form object
winMain = new WinMainForm();
or you could remove all controls on the winMain variable right before adding the new children
foreach(var c in winMainContainer.children){
winMainContainer.children.remove(c)
}

It looks like you aren't creating a new window at all, rather just performing operations on 'winMain' which exists at some higher scope. So every time you call the function you are just adding more and more children to the stackpanel.
You can solve the problem by doing something like this in the beginning of your method.
winMainContainerLeft.Clear();
winMainContainerRight.Clear();
winMainContainer.Children.Clear();
I also noticed that you have included the following lines in your example:
winMainContainer.Children.Remove(winMainContainerLeft);
winMainContainer.Children.Add(winMainContainerLeft);
winMainContainer.Children.Remove(winMainContainerRight);
winMainContainer.Children.Add(winMainContainerRight);
But you don't need to remove them before adding them (this doesn't really make sense anyway.)

dynamically creating window form according to data returned from dataset (C#)

I have a dataset that returns questions and answers from the database, each answer in answer table is linked via a forgein key to the question table.
What I would like to achive is the following:
That a a single dynamic form is created on the first question with all the questions listed under it, meaning the FK_table_Answers = PK_table_Questions on the table_Answers:
(eg) This is Form for Question One:
Question One: How old are you?
Answer One (this is a radio button)
Answer Two (this is a radio button)
Answer Three (this is a radio button)
I have managed to get the above kind of working but the problem is my code keeps generating the forms (eg) 3 times becuase there are three answers, so can anyone point me in right direction how to generate the form dynamically but only ONCE - meaning each successive form is created only once as per the question and that particular questions answers under it.
Kind regards
UPDATED code:
private void LoadDataSets()
{
if (_dataSetQuestionnaire.tbl_QuestionnaireQuestion.Rows.Count == 0)
{
try
{
//Questionnaire:
DataSet1TableAdapters.tbl_QuestionnaireTableAdapter questionnaireAdapter =
new DataSet1TableAdapters.tbl_QuestionnaireTableAdapter();
questionnaireAdapter.Fill(_dataSetQuestionnaire.tbl_Questionnaire);
//Category:
DataSet1TableAdapters.tbl_QuestionnaireCategoryTableAdapter categoryAdapter =
new DataSet1TableAdapters.tbl_QuestionnaireCategoryTableAdapter();
categoryAdapter.Fill(_dataSetQuestionnaire.tbl_QuestionnaireCategory);
//QuestionnaireQuestion:
DataSet1TableAdapters.tbl_QuestionnaireQuestionTableAdapter questionnaireQuestionAdapter =
new DataSet1TableAdapters.tbl_QuestionnaireQuestionTableAdapter();
questionnaireQuestionAdapter.Fill(_dataSetQuestionnaire.tbl_QuestionnaireQuestion);
//QuestionnaieAnswer:
DataSet1TableAdapters.tbl_QuestionnaireAnswerTableAdapter questionnaireAnswerAdapter =
new DataSet1TableAdapters.tbl_QuestionnaireAnswerTableAdapter();
questionnaireAnswerAdapter.Fill(_dataSetQuestionnaire.tbl_QuestionnaireAnswer);
using (DataSet1 dSet = new DataSet1())
{
//Questionnaire:
dSet.Merge(_dataSetQuestionnaire.tbl_Questionnaire);
//Category:
dSet.Merge(_dataSetQuestionnaire.tbl_QuestionnaireCategory);
//QuestionnaireQuestion:
dSet.Merge(_dataSetQuestionnaire.tbl_QuestionnaireQuestion);
//QuestionnaieAnswer:
dSet.Merge(_dataSetQuestionnaire.tbl_QuestionnaireAnswer);
int primaryKeyQuestionnaire = Convert.ToInt32(_dataSetQuestionnaire.tbl_Questionnaire.Rows[0][0]);
foreach (DataSet1.tbl_QuestionnaireRow questionnaire
in _dataSetQuestionnaire.Tables["tbl_Questionnaire"].Select(String.Format("pk_tbl_Questionnaire = {0}", primaryKeyQuestionnaire)))
{
foreach (DataSet1.tbl_QuestionnaireCategoryRow category
in _dataSetQuestionnaire.Tables["tbl_QuestionnaireCategory"].Select(String.Format("fk_tbl_Questionnaire = {0}", questionnaire.pk_tbl_Questionnaire)))
{
foreach (DataSet1.tbl_QuestionnaireQuestionRow question
in _dataSetQuestionnaire.Tables["tbl_QuestionnaireQuestion"].Select(String.Format("fk_tbl_QuestionnaireCategory = {0}", category.pk_tbl_QuestionnaireCategory)))
{
int radiobuttonPosition = 0;
foreach (DataSet1.tbl_QuestionnaireAnswerRow answer
in _dataSetQuestionnaire.Tables["tbl_QuestionnaireAnswer"].Select(String.Format("fk_tbl_QuestionnaireQuestion = {0}", question.pk_tbl_QuestionnaireQuestion)))
{
//Gets the questins via the FK_questionnaireQuestion and fill the _dataSetRadioButtons to generate on dynamic form.
DataSet1TableAdapters.tbl_QuestionnaireAnswerTableAdapter a =
new DataSet1TableAdapters.tbl_QuestionnaireAnswerTableAdapter();
DataSet dSetRadioButtons = new DataSet();
dSetRadioButtons.Merge(a.GetDataByQuestionnaireQuestion(answer.fk_tbl_QuestionnaireQuestion));
_dataSetRadioButtons = dSetRadioButtons;
string theQuestion = question.tbl_QuestionnaireQuestion_Description.ToString();
Form form = new Form();
_form = form;
if(_form == null)
{
_form = new Form();
}
else
{
form.Height = 400;
form.Width = 550;
form.StartPosition = FormStartPosition.CenterScreen;
Label label = new Label();
label.Location = new System.Drawing.Point(5, 10);
label.Size = new System.Drawing.Size(450, 25);
label.Text = theQuestion;
Panel panel = new Panel();
panel.Size = new System.Drawing.Size(300, 200);
panel.Location = new System.Drawing.Point(15, 50);
panel.BackColor = Color.Yellow;
System.Windows.Forms.RadioButton[] radioButtons = new System.Windows.Forms.RadioButton[_dataSetRadioButtons.Tables["tbl_QuestionnaireAnswer"].Rows.Count];
for (int i = 0; i < _dataSetRadioButtons.Tables["tbl_QuestionnaireAnswer"].Rows.Count; i++)
{
radioButtons[i] = new RadioButton();
radioButtons[i].Text = _dataSetRadioButtons.Tables["tbl_QuestionnaireAnswer"].Rows[i]["tbl_QuestionnaireAnswer_Description"].ToString();
radioButtons[i].Location = new System.Drawing.Point(60, 20 + i * 20);
//panel.Controls.Add(radioButtons[i]);
radioButtons[i].Click += new EventHandler(Form1_Click);
Int64 item = Convert.ToInt64(_dataSetRadioButtons.Tables["tbl_QuestionnaireAnswer"].Rows[0].ItemArray[3].ToString());
panel.Controls.Add(radioButtons[i]);
}
Button nextButton = new Button();
nextButton.Text = "Next";
nextButton.Name = "button";
nextButton.Location = new System.Drawing.Point(200, 300);
nextButton.Size = new System.Drawing.Size(150, 25);
nextButton.Click += new EventHandler(nextButton_Click);
form.Controls.AddRange(new Control[] { panel, label, nextButton });
form.ShowDialog();
CreateBoxAndQuestion(form, panel, label);
//form.Dispose();
}
}
}
}
}
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
else
{
MessageBox.Show("Error");
}
}
private void CreateBoxAndQuestion(Form f, Panel p, Label l)
{
for (int i = p.Controls.Count - 1; i >= 0; i--)
{
p.Controls.RemoveAt(i);
}
}

If I understand correctly, you call CreateBoxAndQuestion every time a new question is selected.
But you create (and destroy) the form each time your code enters in this method.
A first approach would be to keep the form, label, button and panel creation outside the method (perhaps in design mode) then passing these controls to the method as
EDIT: Somewhere in your code before entering the load of your next question:
frmQuestion _form = null; // Global
// Create a global instance and keep it without displaying
if(_form == null) _form = new frmQuestion(); // frmQuestion created with panel, label e button via FormDesigner
then when you need to populate _form call
CreateBoxAndQuestion(_form, _form.Panel, _form.Label, questionText);
In this example I pass the _form to CreateBoxAndQuestion, but this is not necessary because is a global. You could change CreateBoxAndQuestion to use directly the global instance.
private void CreateBoxAndQuestion(frmQuestion f, Panel p, Label l, string _label)
{
// Do not display your form here....
}
Now when entering the method clear every RadioButton controls in the panel.Controls collection
for (int i = p.Controls.Count - 1; i >= 0; i--)
{
p.Controls.RemoveAt(i);
}
the rest of the code should change only to reflect the new text assigned to the label and controls and the re-adding of the RadioButtons to the panel. No more creation and reinitialization for Form Label, Button.
label.Text = _label;
Don't forget to destroy _form at the end of your program with _form.Dispose();

Adding dynamic controls to form with auto scroll

When I add my controls to the form, it goes fine until I try to specify a location larger than int16.MaxValue. The controls just pile up on top of each other. Here is code which is simplified but demonstrates the behavior:
private void Form1_Load(object sender, EventArgs e)
{
this.AutoScroll = true;
int nexttop = 0;
for (int i = 0; i < 500; i++)
{
TextBox t = new TextBox();
t.Text = i.ToString();
t.Multiline = true;
if (nexttop > Int16.MaxValue)
{
bool debug = true;
}
t.Location = new Point(0, nexttop);
t.Size = new Size(100, 77);
nexttop += t.Height;
this.Controls.Add(t);
}
}
I want to avoid moving the scroll bar programaticaly, since this causes timing issues.
Do you have any ideas on how to fix this? TIA.

This limit (32767) is due to GDI+. I believe different behaviours may be observed according to the Windows version.