C# communication between forms bug - c#

I'm working on a GUI for an admin interface for management of a student complex. Currently the GUI has a listbox with predefined 6 rules for the students. In the beginning of the code, I add them to a list
private void Form1_Load(object sender, EventArgs e)
{
foreach (string rule in lbRules.Items)
ruleList.Add(rule);
}
Then, the GUI provides the admin with an option to modify the rules. To do so he selects a rule from the listbox and clicks a "Modify" button, which opens another form:
private void BtnModify_Click(object sender, EventArgs e)
{
if (lbRules.SelectedItems.Count > 0)
{
selectedRule = lbRules.SelectedItem.ToString();
selectedIndex = lbRules.SelectedIndex;
selectedRuleNumber = selectedRule.Substring(0, 3);
selectedRule = selectedRule.Substring(6);
var rulesForm = new Rules();
rulesForm.Show();
}
}
On the second form load event I get the rule's text and number:
private void Rules_Load(object sender, EventArgs e)
{
tbRule.Text = Form1.selectedRuleNumber;
tbModifyRule.Text = Form1.selectedRule;
}
The text gets added to a RichTextBox, from where the rule can be edited.
Then the admin clicks a "Save" button, which gets the edited text from the RichTextBox(tbModifyRule) and adds it to a static ruleList in form1, sets a static boolean from form1 to true. Afterwards the second form gets closed:
private void BtnSave_Click(object sender, EventArgs e)
{
saveRule = Form1.selectedRuleNumber + " - " + tbModifyRule.Text;
Form1.ruleList.Insert(Form1.selectedIndex, saveRule);
Form1.ruleList.RemoveAt(Form1.selectedIndex+1);
Form1.formOpen = true;
this.Dispose();
}
At this point we are back to form1, in which we have a timer with timer_tick event. In there we check whether the boolean formOpen is true (which it is set before closing form2). Inside the if statement we clear the listbox and add each rule from the ruleList (previously edited in form2) to the listbox, then sets the formOpen back to false so it doesn't get executed all the time:
if (formOpen)
{
lbRules.Items.Clear();
foreach (string item in ruleList)
lbRules.Items.Add(item);
}
formOpen = false;
Now this is really weird, and at this point makes absolutely no sense to me, since I tried debugging it for over an hour, trying different ways, which also led me to mysterious wonders of WHY TF IT WORKS WHENEVER IT WANTS...
So this works randomly, like it would work the first time, the second and third times it won't. Or vice versa. It's all random.
Strangely, I tried adding a breakpoint on the
lbRules.Items.Add(item);
in the foreach loop, so it stops on each item. And I actually saw the changed rule getting added from the ruleList into the listBox, however in the end it was not there.
And weirdly enough, I also tried adding the text from form2 in the listBox in form1, without using a list, but for whatever odd reason, I use the int selectedIndex, which gets the index of the selected item from the BtnModify_Click event to insert the text in that particular index, but this very index gets RANDOMLY set to bloody 0 after form2 closes.
hence, it again works from time to time, because at some tries it doesn't get set to 0 and it works.
if (formOpen)
{
selectedRule = Rules.saveRule;
lbRules.Items.Insert(selectedIndex, selectedRule);
lbRules.Items.RemoveAt(selectedIndex+1);
}
formOpen = false;
I don't assign value to this integer ANYWHERE else in the code.
I really tried digging some sense, but I hit a solid hard rock.
Any help appreciated!
And thanks for the time!
edit1:
as requested - rest of the timer method
private void Timer1_Tick(object sender, EventArgs e)
{
foreach (string text in ws.messages)
message = text;
if (ws.messages.Count > 0)
{
if (message.Contains("comp"))
{
Complaints();
message = String.Empty;
ws.messages.Clear();
}
}
if (formOpen)
{
lbRules.Items.Clear();
foreach (string item in ruleList)
lbRules.Items.Add(item);
}
formOpen = false;
}

I would change your code to the following:
if (formOpen)
{
formOpen = false;
lbRules.Items.Clear();
foreach (string item in ruleList)
lbRules.Items.Add(item);
}
The issue with having the formOpen = false; outside the if statement is that there is a chance that once the user clicks the Save button the timer could be about to execute the formOpen = false instruction setting it to false making the code inside the If statement to never be executed.
I truly believe this is not random but just a timing issue due to complicated logic.

If I were you, I'd do a couple things:
Use a separate class for data exchange between forms, avoid using public static (I assume) form members for this.
Instead of a timer, subscribe to the Form.Closed event of RulesForm
This might make code flow a bit more predictable and allow you to find errors more easily.
Better yet, use the following pattern:
class Form1
{
private void BtnModify_Click(object sender, EventArgs e)
{
var ruleData = ..... //get current rule data
var rulesForm = new Rules();
rulesForm.SetData(ruleData); //pass initial state to the form
rulesForm.SaveChanges = this.ApplyRules; //pass a method which will be called on save
rulesForm.Show();
}
private bool ApplyRules(RuleData ruleData)
{
//do whatever you like with the rules here
return true;
}
}
class RuleForm
{
public void SetData(RuleData ruleData)
{
//initialize fields, etc
}
public Func<RuleData, bool> SaveChanges { get; set; }
private void BtnSave_Click(object sender, EventArgs e)
{
var ruleData = .... //get data from form fields
if(this.SaveChanges(ruleData))
this.Close();
}
}
class RuleData
{
//whatever data you need
}

Related

Program for learning foreign words C#

I am in the process of writing a vocabulary program. C # Windows Form.
Description of the program operation:
Use the buttons to select the location of text files with the words "PL" and "ENG". (two separate files)
Click the start button to start the program
the first word from the board appears in the label
I'm translating the word into the textbox and the Messagebox "OK" or "WRONG" pops up
And here a problem arises. The program instead of every time I wait until I introduce a new word to the textbox, it loops, the questions in the label are changed and MessageBox displays.
How best to do this to make the program work correctly? `` `[
private void sprawdzButton_Click(object sender, EventArgs e)
{
BazaSlow.bazaPolskichSlowek = _fileReader.Read(adresPlikuPL);
BazaSlow.bazaAngielskichSlowek = _fileReader.Read(adresPlikuANG);
string odpowiedz = odpTextBox.Text;
int i = 0;
while (i < BazaSlow.bazaPolskichSlowek.Length)
{
trescSlowkaLabel.Text = BazaSlow.bazaPolskichSlowek[i];
if (odpowiedz.Equals(BazaSlow.bazaAngielskichSlowek[i].ToLower()))
{
MessageBox.Show("OK");
}
else
{
MessageBox.Show("ŹLE");
}
i++;
}
}
This approach will not quite work.
If you use WinForms then you can do it via events. I'll quickly use english variable names since I don't speak your language.
This could be one approach to do it: I used the "TextChanged" event from the textBox.
string[] wordsLanguage1;
string[] wordsLanguage2;
int currentIndex = 0;
private void Form1_Load(object sender, EventArgs e)
{
wordsLanguage1 = System.IO.File.ReadAllLines("somePath1");
wordsLanguage2 = System.IO.File.ReadAllLines("somePath2");
}
private void ReportAndCheckInput(string input)
{
if (input.ToLower().Equals(wordsLanguage2[currentIndex].ToLower())) {
//right translation
currentIndex++;
label1.Text = wordsLanguage1[currentIndex];
textBox1.Text = "";
}
else
{
//wrong translation
}
}
private void textBox1_TextChanged(object sender, EventArgs e)
{
ReportAndCheckInput(textBox1.Text);
}
Now this approach uses the TextChanged event. So the ReportAndCheckInput method will be called on every text-change. That means that your Feedback would pop up on every keystroke which would not be nice. You could use any other event instead of TextChanged. For example a button click. Another solution would be to use a label for your feedback and not a message box. Then the user would never have to click anything but woudl instantly see whether or not he was correct.

Circular loop when using selection changed datagrdivew

I am using a datagradview and I am wanting to prompt the user to save the current row before moving off I have been trying to use the following event but I seem to be in a circular loop when I hit my save event.
private void dgStock_SelectionChanged(object sender, EventArgs e)
{
if (isDirty == true)
{
isSavedFromRow = true;
btnSaveDetails_Click(sender, e);
isDirty = false;
}
}
The problem with the selection changed event is this happens once the row has changed so the user could think their saving the new row and not the current row.
I also seem to be caught in a circular loop some how has the messagebox box is getting fired numerious times I am only setting the isDirty to true if the user enters key down on my textboxes.
if (isDirty == true)
{
DialogResult _result = MessageBox.Show("Are you sure you wish to upate Live Product Information", "Save Changes", MessageBoxButtons.YesNo, MessageBoxIcon.Information);
if (_result == DialogResult.Yes)
{
updateStock();
_trackChanges.Clear();
isDirty = false;
}
}
This is me setting my dirty flag on key down felt this was best way to avoid the problem I seem to be having.
private void txtDescription_KeyDown(object sender, KeyEventArgs e)
{
isDirty = true;
btnSaveDetails.Enabled = true;
}
Your code sample suggests that your save stuff is defined in your save button click. If you change your structure to something like this
private void SaveClick(object sender, EventArgs e)
{
DoSaveStuff();
}
private void DoSaveStuff()
{
// Do your save stuff
}
i.e. pull your save stuff out into a method. You can call DoSaveStuff() whenever you need to save, e.g.
private void SelectionChanged(object sender, EventArgs e)
{
// Do stuff
if (condition)
{
DoSaveStuff();
}
}
The advantage of this approach is you're capturing the aspect of the behaviour you're interested in - the save stuff - rather than the whole button click. Furthermore, you click a button to save, your application doesn't, it simply saves in certain circumstances, e.g. when you click a button or when something changes.
As MSDN says the SelectionChangedEvent occurs whenever the selection has changed. So, whenever this happens you could check your original selection to see if it has changed and then save if it has. Maybe doing something like this
private void SelectionChanged(object sender, EventArgs e)
{
bool hasContentsChanged = // determine if your content has changed
if (hasContentsChanged)
{
DoSaveStuff();
}
}
An advantage of this approach is that you'd only have to save if it really had changed, i.e. if the original text != new text, rather than in all cases.

Winforms C# Disable/ Enable Button on Treenode Click

I have a treenode which displays a checklist from a SQL database. I have a method to get the selected workflows.
I want to enable the run button if a checkbox is checked and disable the button if nothing is checked and on load.
I'm not sure where to put this if statement. I have tried putting it under the run button on the click action but it is not working correctly.
Any help is appreciated.
List<WorkflowViewModel> workflowViewList = new List<WorkflowViewModel();
var workflowList = GetSelectedWrokflows();
if (workflowList.Count == 0)
{
button.enabled = false;
}
else
{
button.enabled = true;
}
One way to do this is to create a method that will do the work of determining the selected workflow items and enabling or disabling the button. By putting the code in a single method, it allows you to call it from multiple places, and if you need to change the behavior, you only have one place to make the modifications.
Then you can just call this method from the Form_Load event, and from the checked list box's ItemCheck event:
public partial class Form1 : Form
{
List<WorkflowViewModel> workflowViewList = new List<WorkflowViewModel>();
private void SetRunButtonState()
{
workflowViewList = GetSelectedWorkflows();
button.Enabled = workflowViewList.Count > 0;
}
private void Form1_Load(object sender, EventArgs e)
{
SetRunButtonState();
}
private void treeView1_AfterCheck(object sender, TreeViewEventArgs e)
{
SetRunButtonState();
}
// Rest of class code omitted...
}

check dropdown menu if matches

Long story short: There are specific tags given (like Pop, Rock, Metal) and the User should write into a textbox and every time he adds a char the given tags are checked if one (or more) matches. At the moment I'm using a combobox with the following code:
private void EnterComboBox_TextChanged(object sender, EventArgs e)
{
List<string> AllTags = new List<string>();
AllTags.Add("Pop");
if (AlleTags[0].ToLower().StartsWith(EnterComboBox.Text.ToLower()))
{
EnterComboBox.Items.Clear();
EnterComboBox.Items.Add("Pop");
EnterComboBox.DroppedDown = true;
}
}
this is working fine but the problem is, that after the first char entered the dropbox drops down and the entered text is marked and will be overwritten when a new char is entered. Any ideas how I could fix this? Every idea is welcome it doesn't have to be a combo box :)!
Edit:
After some more (detailed) research I realized I could explain it like this: Basically I want the combobox the behave like the search-bar from google. The users enters letters and in the dropdown menu are autocomplete suggestions
At the moment I solved it like this:
I placed a textbox in front of a combobox so that only the arrow of the combobx is visible and if you click on it you automatically write in the textbox.
public Form1()
{
InitializeComponent();
EingabeTextBox.AutoSize = false;
EingabeTextBox.Size = new Size(243, 21); //the size of the combobox is 260;21
}
private void EingabeTextBox_TextChanged(object sender, EventArgs e)
{
EingabeComboBox.Items.Clear();
List<string> AlleTags = new List<string>();
AlleTags.Add("Example");
if (AlleTags[0].ToLower().StartsWith(EingabeTextBox.Text.ToLower()))
{
EingabeComboBox.Items.Add(AlleTags[0]);
EingabeComboBox.DroppedDown = true;
}
}
For me it would work like this. I hope I can help someone else with this too, but I am still open for any better ideas :)!
Changing the ComboBox entries while typing into it obviously creates undesired interferences. Instead combine a TextBox and a ListBox.
private bool changing;
private void TextBox_TextChanged(object sender, EventArgs e)
{
if (!changing) {
changing = true;
try {
// manipulate entries in the ListBox
} finally {
changing = false;
}
}
}
private void ListBox_IndexChanged(object sender, EventArgs e)
{
if (!changing) {
changing = true;
try {
// Put selected entry into TextBox
} finally {
changing = false;
}
}
}
The changing guard makes sure that the ListBox does not influence the TextBox while you are entering text into the TextBox and vice versa.
The try-finally ensures that the guard will be reset in any circumstances, even if an exception should occur.

How to determine whether TextChanged was triggered by keyboard in C#?

I have a method
private void textBoxPilot_TextChanged(object sender, TextChangedEventArgs e)
{ ... }
where the textbox in question takes a search string from the user and populates a ListBox with the results on every keystroke.
Subsequently, when an item is picked from the ListBox, I would like the choice reflected in the same Textbox. However, I don't want to trigger the search mechanism, which would cause the Listbox to forget its selection.
How can I determine whether the TextChanged event was triggered by the user (via they keyboard or maybe copy/paste) or by another method using textBoxPilot.Text = "Pilot name";?
Thanks.
bit of a hack, but....
public class MyForm : Form
{
private bool _ignoreTextChanged;
private void listView1_SelectionChanged( object sender, EventArgs e )
{
_ingnoreTextChanged = true;
textBoxPilot.Text = listView1.SelectedValue.ToString(); // or whatever
}
private void textBoxPilot_TextChanged( object sender, TextChangedEventArgs e )
{
if( _ignoreTextChanged )
{
_ignoreTextChanged = false;
return;
}
// Do what you would normally do.
}
}
A disabled control will not fire a event. So two options are either always disable update the text then re-enable or create a derived class wrapper (using this method you could still do data binding)
class myClass : TextBox
{
public virtual string TextWithoutEvents
{
get
{
return base.Text;
}
set
{
bool oldState = Enabled;
Enabled = false;
base.Text = value;
Enabled = oldState;
}
}
}
If the user selects "Pilot name" from the list, you set the text box to "Pilot name". This will cause the list box to select "Pilot name". So the selection should be kept. You just have to break the recursion.
In my scenario where user has to type in text to trigger auto-complete and we didn't want a re-trigger when the auto-complete changes the text again, I used the text lengths. This won't work if user copy/pastes and therefore adds more than 1 character at a time with the keyboard.
private void HandleTextChanged(object sender, TextChangedEventArgs e){
var oldText = e.OldTextValue;
var newText = e.NewTextValue;
// Assuming text changed from keyboard is always 1 character longer,
// ignore this text changed event if new text > 1 character longer.
if (newText.Length > oldText.Length + 1) {
return;
}
...
}
In your scenario, if you always know the values you want to skip, then you could check for them instead:
if (newText == "Pilot name") {
return;
}
or
if (myListOfNamesToIgnore.Contains(newText)) {
return;
}

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