Silverlight C# - How to hold loop progress until an event completes? - c#

I'm trying to loop through the text in a textbox by word in order to spellcheck it. I've split the contents of the textbox into an array, and loop through each word in the array and run it through the spellchecker. When a misspelling is found, I have a popup with a listbox inside it display so that you can choose the correction.
The issue that I'm having, is that it just loops through the whole array and only ends up showing the last correction that needs to be done.
How do I pause the loop so that it waits for a selection to be made and then resume?
Here's the code for the loop:
foreach(string checkedWord in articleWords)
{
bool success = _spellChecker.CheckWord(checkedWord);
List<string> suggest;
if (!success)
{
suggest = _spellChecker.GetSuggestions(checkedWord);
SpellChecklistBox.Items.Clear();
foreach (string s in suggest)
{
SpellChecklistBox.Items.Add(new ListBoxItem() { Content = s });
}
SpellCheckerPopup.IsOpen = true;
SpellChecklistBox.Items.Add(new ListBoxItem() { Content = " ----------------------" });
SpellChecklistBox.Items.Add(new ListBoxItem() { Content = "Ignore" });
}
}
When the SpellCheckerPopup displays, I have an event trigger in the listbox on SelectionChange.
Basically, I need to pause the loop somehow, and then when the SelectionChange event does it's thing, have the loop resume.
Thanks in advance!
-Sootah

If I'm not misunderstanding, currently you are going to:
(1) Check each word in the loop
(2) Pause the loop when an error is found and pop up a suggestion window
(3) User select a suggestion word and resume the loop
I think it's better and easier if the solution is:
(1) Check the word from the first one
(2) Quit the check method with an error flag, and store the position in a variable, pop up a suggestion window
(3) User selects a suggestion word and when User has confirmed the suggestion(e.g. pressing OK on the suggestion window), start the CheckWordMethod again from the stored position
(4) Until step (2) quits with no error flag, which means all words are correct now (but make sure in the whole progress, users can only modify the words by your suggestion window)

#The Smartest: Your answer lead me in the correct direction; actually ended up learning a new datatype out of it! Never used a Queue before. (Which made it a HELL of a lot simpler than having to track where in the array I was at, as I first figured I thought I'd have to.. :)
Anyway, I'll accept your answer, but here's the code I ended up doing: (The actual replacing of the word in the textbox I've not implemented yet.)
private void btnSpelling_Click(object sender, RoutedEventArgs e)
{
SpellChecklistBox.Items.Clear();
string[] articleWordsArray = txtArticle.Text.Split(' ');
foreach (string word in articleWordsArray)
{
articleWords.Enqueue(word);
}
CorrectWord();
}
private void SpellChecklistBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
SpellCheckerPopup.IsOpen = false;
}
private void SpellCheckerPopup_Closed(object sender, EventArgs e)
{
CorrectWord();
SpellChecklistBox.Items.Clear();
}
Queue<string> articleWords = new Queue<string>();
private void CorrectWord()
{
if (articleWords.Count() > 0)
{
string checkedWord = articleWords.Dequeue();
bool success = _spellChecker.CheckWord(checkedWord);
List<string> suggest;
if (!success)
{
suggest = _spellChecker.GetSuggestions(checkedWord);
foreach (string s in suggest)
{
SpellChecklistBox.Items.Add(new ListBoxItem() { Content = s });
}
SpellCheckerPopup.IsOpen = true;
SpellChecklistBox.Items.Add(new ListBoxItem() { Content = " ----------------------" });
SpellChecklistBox.Items.Add(new ListBoxItem() { Content = "Ignore" });
SpellCheckerPopup.IsOpen = true;
}
}
}
It's all pretty straight forward courtesy of the Queue datatype. When the spelling button gets clicked it loads the TextBox into an array, and then I loop through the array to enqueue the items into the articleWords queue, after which it calls CorrectWord(). CorrectWord() then loads the relevant list after dequeueing from articleWords, and on the PopUp. Closed event it clears the ListBox and calls CorrectWord() which will keep bringing back the PopUp until there are no more words to be corrected. :)

Related

How to use functions step by step

Sorry for the strange title, I just don't know how to name this question.
So I have such a function say().
void say(string printedText) {
gameText.text = printedText;
}
And I need to use it several times. Something like this:
say("test text 1");
say("test text 2");
say("test text 3");
...
I need to change text by clicking Space button. Of course I need to use something like this:
if(Input.GetKeyDown(KeyCode.Space)) {
...
}
But I can't understand how to show text step by step. So for example if I click Space button once I should see "test text 1". Next click should show me "test text 2" etc.
How can I realise it? Thanks in advance.
Depending on your needs you could store different texts in a List<string> or maybe even Queue<string> and do
List example
// Add your texts in the editor or by calling texts.Add(someNewString)
public List<string> texts = new List<string>();
private int index = 0;
if(Input.GetKeyDown(KeyCode.Space))
{
// have a safety check if the counter is still within
// valid index values
if(texts.Count > index) say(texts[index]);
// increase index by 1
index++;
}
Array example
Basically the same as the List<string> but you can't add or remove elements "on the fly" (at least not that simple)
public string[] texts;
private int index = 0;
if(Input.GetKeyDown(KeyCode.Space))
{
// have a safety check if the counter is still within
// valid index values
if(texts.Length > index) say(texts[index]);
// increase index by 1
index++;
}
Queue example
public Queue<string> texts = new Queue<string>();
for adding a new text to the end of the queue do
texts.Enqueue(someNewString);
and then
if(Input.GetKeyDown(KeyCode.Space))
{
// retrieves the first entry in the queue and at the same time
// removes it from the queue
if(texts.Count > 0) say(texts.Dequeue());
}
Simple counter
If it is really just about having a different int value then yes simply use a field
private int index;
if(Input.GetKeyDown(KeyCode.Space))
{
// uses string interpolation to replace {0} by the value of index
say($"test text {0}", index);
// increase index by one
index++;
}
define a class field like this:
int count = 0;
and now everytime space is hit:
if(Input.GetKeyDown(KeyCode.Space)) {
say("test text " + count);
count = count + 1;
}
This Code:
if(Input.GetKeyDown(KeyCode.Space)) {
...
}
only works for Unity, In Visual Studio you'll have to create an Event to whatever object you want to do this, for example, if you want to call a void each time you press spacebar youll have to do this, it is easy: (Image below)
In the propieties window press the bolt icon and after double click on the event you want to create (samples): TextChanged, LocationChnaged, MouseMove, etc...
I will use KeyDown on the TextBox object
image
Now in your code this void should be generated
image
Inside this void i writed the code and this is how it looks:
(put int n = 1 before voids)
private void textBox1_KeyDown(object sender, KeyEventArgs e)
{
if(e.KeyCode == Keys.Space)
{
//int n = 1; must be defined
textBox1.Text = "test text " + n;
n++;
}
}
Now each time you'll press or stay pressed spacebar the textbox will be filled with "test text " and the value will be 1 more each time.

How do I make one word in a text box end a program?

So one of the forms I have to create is where you enter a first and last name and then it splits the two names and puts them next to the appropriate labels, form design: https://gyazo.com/9b34dca0c1cd464fd865830390fcb743 but when the word stop is entered in any way e.g. Stop, StOp, sToP etc. it needs to end.
private void btnSeparate_Click(object sender, EventArgs e)
{
string strfullname, strgivenname, strfamilyname, strfirstname;
int int_space_location_one, int_space_location_two;
strfullname = txtFullName.Text;
int_space_location_one = strfullname.IndexOf(" ");
strgivenname = strfullname.Substring(0, int_space_location_one);
lblGivenEntered.Text = strgivenname;
strfirstname = strfullname.Remove(0, int_space_location_one + 1);
int_space_location_two = strfirstname.IndexOf(" ");
strfamilyname = strfirstname.Substring(int_space_location_two + 1);
lblFamilyEntered.Text = strfamilyname;
}
This is my current code, I have tried many different ways to get the word stop to end it but it wont work so that's why there is currently no code trying to stop the program, the main problem I get is because it is searching for a space between the first and last name and it obviously doesn't have one for one word it just crashes.
Any help with this would be amazing, thanks in advance.
Just hook up the TextChanged event and go like this:
private void TextChanged(Object sender, EventArgs e)
{
// If text, converted to lower-characters contains "stop" -> Exit
if(txtFullName.Text.ToLower().Contains("stop"))
{
// What I understand as "stopping it".
Application.Exit();
}
}
IF with "stop it" you mean to cancle the operation:
private void btnSeparate_Click(object sender, EventArgs e)
{
// If text, converted to lower-characters contains "stop" -> Exit
if (txtFullName.Text.ToLower().Contains("stop"))
{
// What I understand as "stopping it".
Application.Exit();
}
else
{
// Your code inside the else block
}
}
Short version of everything: Also covering no spaces problem
private void btnSeparate_Click(object sender, EventArgs e)
{
// Save how many words are inside
int wordsInText = txtFullName.Text.Split(' ').Length;
// Save if "stop" was typed into the textbox
bool stopExisting = !txtFullName.Text.ToLower().Contains("stop");
// If text has exactly 3 words and "stop" is NOT existing
if (wordsInText == 3 && !stopExisting)
{
// Save array of splitted parts
string[] nameParts = txtFullName.Text.Split(' ');
// This is never used??
string strfirstname = nameParts[1];
// Set name-parts to labels
lblGivenEntered.Text = nameParts[0];
lblFamilyEntered.Text = nameParts[2];
}
// If text has NOT exactly 3 words and "stop" is NOT existing
else if(wordsInText != 3 && !stopExisting)
{
// If there are no 3 words, handle it here - MessageBox?
}
// If "stop" IS existing
else if(stopExisting)
{
// If text contains "stop" handle it here
// Application.Exit(); <-- if you really want to exit
}
}
You could just check, if one of the entered words is equal to the word "stop". There you need a StringComparions which ignores the case. Or you could parse the entered word into lower/upper-cases.
So if the check is true, you could just end the program with
Environment.Exit(0);
You could just check, if one of the entered words is equal to the word "stop". There you need a StringComparions which ignores the case. Or you could parse the entered word into lower/upper-cases.
So if the check is true, you could just end the program with
Environment.Exit(0);
Code:
if (strfullname.ToLowerInvariant().Contains("stop"))
{
Environment.Exit(0);
}

How can i load items back to the listView control from text file and also add checkBoxes near each item faster?

In this method i'm reading a text file from my hard disk and add the items to the listView.
I also changed in the form1 designer on the listView propeties the property CheckBoxes to true.
Now when i'm running my program it's taking like 10-15 seconds to load it up all.
The form1 constructor:
LoadtoListView();
And the method LoadtoListView:
private void LoadtoListView()
{
int countit = 0;
using (StreamReader sr = new StreamReader(#"c:\listviewfile\databaseEN.txt"))
{
while (-1 < sr.Peek())
{
try
{
string name = sr.ReadLine();
string email = sr.ReadLine();
var lvi = new ListViewItem(name.Substring(name.IndexOf(":") + 1));
lvi.SubItems.Add(email.Substring(email.IndexOf(":") + 1));
listView1.Items.Add(lvi);
countit++;
}
catch (Exception) { }
}
sr.Close();
numberofforums = countit;
}
}
There are 547 items to load and 547 checkBoxes.
I tested now if i change in the designer the listView property of the CheckBoxes to false again it will load fast about 1-2 seconds.
But once i'm turning this property of the CheckBoxes to true it's tkaing more then 10-15 seconds to load.
I guess the problem is that it's taking time to draw all the CheckBoxes.
Is there any way to make it all faster ?
There exist a couple of ways you could make that faster. Actually you could make it blazingly fast, checkboxes or no checkboxes.
Your code requires a few tweaks here and there and you must think about reusability, concern separation and parameterisation.
For instance, the method name LoadToListView is already doing too much work. It loads stuff, and it also populates the listview.
There are 3 ingredients that can get you to Nirvana.
First of all
consider creating an up front materialised list of ListViewItem instances, more particularly, create a primitive array, such as this (by the way, I will also sprinkle some other good practices along the way, even though it is not the lacking of those practices which causes your delays):
public ListViewItem[] LoadItems(string filePath) {
// not hardcoding the filePath is a good idea
List<ListViewItem> accumulator = new List<ListViewItem>();
int countit = 0;
using (StreamReader sr = new StreamReader(filePath)) {
while (-1 < sr.Peek()) {
try
string name = sr.ReadLine();
string email = sr.ReadLine();
var lvi = new ListViewItem(name.Substring(name.IndexOf(":") + 1));
lvi.SubItems.Add(email.Substring(email.IndexOf(":") + 1));
// instead of adding this item to the list
// --> no more this:: listView1.Items.Add(lvi);
// just "accumulate" it
accumulator.Add(lvi);
countit++;
}
catch (Exception) { }
}
// no need to manually close the reader
// sr.Close();
// the using clause will close it for you
numberofforums = countit;
}
return accumulator.ToArray();
}
Okay.. So we've created an array of ListViewItem.
"So what?" you might think.
Well, for each and every Add invocation on your ListView, the ListView will try to react graphically (even if the GUI thread is occupied it will still try). What this reaction is is not for this answer to be concerned. What you must understand is that instead of Add you could call AddRange which takes a primitive array of ListViewItem as its parameter. That will cause just one graphical reaction for all the set of ListViewItem instances which means it will speed up your app a lot.
So here's ingredient number 2
Make another method which calls LoadItems and then calls AddRange on the ListView:
public void SomeOtherPlace() {
string filePath = #"....";
ListViewItem[] items = LoadItems(filePath);
this.listView1.Items.AddRange( items );
}
This will have already given your app the extra speed you were looking for, but even if the next step will not make your app elegant, it will surely help.
And ingredient number 3 :: Asynchrony
It would be grand if your UI didn't freeze while the LoadItems method was being called.
This "non freezing" ability can be achieved in many ways, but the most modern and coolest way is to use Task<T> and the async and await operators introduced in .NET 4.5 and C# 5.0.
If you don't have a clue about what these things are then, just enjoy the first two ingredients but don't hesitate to learn about the entities I've mentioned.
Basically what you need to do is:
make sure you can't possibly call SomeOtherPlace() twice, since what we're about to do is to make this a possibility. So if you have a button's event handler, for instance, which is calling SomeOtherPlace then we should disable that button and reenable it once we're done
we will make the SomeOtherPlace() method be an async method, which allows it to await tasks
we will run the LoadItems code on a separate thread all nicely wrapped in a Task<ListViewItem[]> and await it on the GUI thread
Let's go. The first change is this:
public void SomeOtherPlace() {
becomes
public async void SomeOtherPlace() {
Secondly, we disable the button I talked about:
public async void SomeOtherPlace() {
this.button1.Enabled = false;
...
this.button1.Enabled = true;
}
Third, we turn this line:
ListViewItem[] items = LoadItems(filePath);
into this:
ListViewItem[] items = await Task.Factory.StartNew(() => LoadItems(filePath));
Now your method should look something like this:
public async void SomeOtherPlace() {
string filePath = #"....";
ListViewItem[] items = await Task.Factory.StartNew(() => LoadItems(filePath));
this.listView1.Items.AddRange( items );
}
Hope I didn't forget anything.
Good luck and don't settle for not understanding how things work under the hood!
Use listView1.Items.AddRange instead of adding one ListViewItem at a time. This should improve your load time.

Looping Text label in C#?

i have a timer that changes a label's text each tick. For some reson, it stop and does not continue looping. Why?
private int count = 0;
private void timer1_Tick(object sender, EventArgs e)
{
string[] arr4 = new string[3]; // 4
arr4[0] = "one";
arr4[1] = "two";
arr4[2] = "three";
if (count == 4)
{
count = 0;
}
toolStripStatusLabel1.Text = arr4[count];
count++;
}
Also, when my form loads, the label's text is blank. Then it goes to arr4[0]. When it loops again, the text starts at arr[0]. Why is the text blank first, and how do i fix it?
Looks like your original question was answered in the comments. I'll answer your second question from the comments.
Your timer1_Tick event doesn't execute immediately when your program starts. The first time it executes is after 5000ms, in your case. So the label will show blank at first, then change to the value of arr4[0]. If you don't want that, you could:
set the value of the label in the designer at design time
set the value of the label in the constructor at run time
pull the creation of the array out of the timer tick event so you're not recreating it every 5 seconds, make it a class variable, and create it in the constructor and then set the label to arr4[0] immediately after creating it

WPF - print during a loop

I have a simple issue, but the solution appears to be tricky. I want to print using the WPF control canvas during a loop; but for each iteration, I want to udpate the canvas control.
If I want to print a canvas control in WPF, I can simply call
PrintDialog dialog = new PrintDialog();
dialog.PrintVisual(this.canvas, "");
And it prints as expected to my default printer. Wonderful.
However, if I want to perform this multiple times in a loop and make an update to the canvas during each iteration, only the final iteration of the loop is printed.
private void methodName()
{
for (int i = 0; i < 2; i++)
{
updateTextBox(i.ToString());
PrintDialog dialog = new PrintDialog();
dialog.PrintVisual(this.canvas, "");
}
}
private void updateTextBox(string text)
{
txtTextBox.Text = text;
}
Any idea what I need to do to ensure that I get 2 print outs, the first with the txtTextBox.Text value of 0, the second time it has the value of 1?
I am about to implement something similar in my application and found out that my previous answer wasn't good enough. The problem for me was that although the canvas is updated in each iteration, it has not yet rendered itself before being sent to PrintVisual. It surprises me that you get your final iteration printed, I only got the first one. Anyway, this is how I made it work, basically queueing the print command after the already pending render operation:
for (int i = 0; i < 2; i++)
{
updateTextBox(i.ToString());
this.canvas.InvalidateVisual(); // Maybe not needed in your case
PrintDialog dialog = new PrintDialog();
this.Dispatcher.Invoke(System.Windows.Threading.DispatcherPriority.Render, (Action)delegate()
{
dialog.PrintVisual(this.canvas, "" + i);
});
}
Yes it's somewhat similar (but not identical) to SalGad's answer and the post you're referring to, but I'm not able to comment that answer, so please try this out, it works for me.
I also had problems with disappearing prints when using empty description for the print jobs, thus the + i. Don't know if that is a generic problem, or just something with my printer setup.
I got the idea from this post, which also mentions an alternative solution using ViewBox.
OK
I solved it.
I removed all the dispatcher object methods so it runs on a single thread.
To update the canvas, I used the canvas.UpdateLayout() method.
I also ensured that the print had finished before updating the next canvas (the next iteration).
private void methodName()
{
for (int i = 0; i < 2; i++)
{
updateTextBox(i.ToString());
this.canvas.UpdateLayout();
PrintDialog dialog = new PrintDialog();
dialog.PrintVisual(this.canvas, "ABC");
dialog.PrintQueue.Refresh();
while (dialog.PrintQueue.NumberOfJobs != 0)
{
bool isQueued = false;
foreach (var job in dialog.PrintQueue.GetPrintJobInfoCollection())
{
if (job.Name == "ABC")
isQueued = true;
}
if (!isQueued)
break;
Thread.Sleep(500);
dialog.PrintQueue.Refresh();
}
}
}
private void updateTextBox(string text)
{
txtTextBox.Text = text;
}
I also could have just done thread.sleep(3000) - this worked as it was enough time to ensure the print job had completed, but it was also a little bit 'hopeful' and I wanted something more secure.
Thank you to everyone for your suggestions.
If you are going to call PrintVisual multiple times you have to look into PrintDocument and DocumentPaginator.
Just a guess, but it might be worth trying RenderTargetBitmap to force rendering the canvas in each iteration, and then create an Image with that source, which then can be sent to PrintVisual. See this post for code example:
Printing viewport
Just taking a shot here, but can you try refreshing the WPF canvas controls at the start of every for loop iteration? Here is the code snippet:
// declare this
public static class ExtensionMethods
{
private static Action EmptyDelegate = delegate() { };
public static void Refresh(this UIElement uiElement)
{
uiElement.Dispatcher.Invoke(DispatcherPriority.Render, EmptyDelegate);
}
}
// the loop
for (int i = 0; i < 2; i++)
{
updateTextBox(i.ToString());
PrintDialog dialog = new PrintDialog();
dialog.PrintVisual(this.canvas, "");
}
}
// update this method
private void updateTextBox(string text)
{
txtTextBox.Text = text;
txtTextBox.Refresh();
Thread.Sleep(500);
}
I am sourcing this idea from here

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