C# combobox if statement + continue button incorporation - c#

This code doesn't work. I don't know what to fix.
public sealed partial class Home : Page
{
public Home()
{
this.InitializeComponent();
ComboBox1.Items.Add("Hindiiiii");
}
string selection = null;
private void ComboBox1_SelectedIndex(object sender, EventArgs e)
{
if (ComboBox1.SelectedIndex!=1)
{
selection = ComboBox1.SelectedItem.ToString();
}
}
private void Continue(object sender, RoutedEventArgs e)
{
if(selection != null)
{
if (selection == "Hindiiiii")
this.Frame.Navigate(typeof(MainPage));
else if (selection == "English")
this.Frame.Navigate(typeof(Home));
}
}
When a user selects Hindiiiii on the main screen and clicks continues he is not redirected to the next page (MainPage).

Let's say your main page looks like this:
You can store the selection in a variable:
string selection = null;
private void ComboBox1_SelectedIndex(object sender, EventArgs e)
{
if (ComboBox1.SelectedIndex!=-1)
{
selection = ComboBox1.SelectedItem.ToString();
}
}
Then in your click event you can pass parameters between your pages:
private void Continue(object sender, RoutedEventArgs e)
{
if(selection != null)
this.Frame.Navigate(typeof(SomePage), selection); //send the contents of the variable to another page
}
And let's say you had another page with a TextBox and a TextBlock:
In your other pages' OnNavigatedTo event, you can retrieve the parameters so you don't have to create a page for every selected language:
string selection = null;
protected override void OnNavigatedTo(NavigationEventArgs e)
{
selection = e.Parameter.ToString();
languageTextBlock.Text = selection; //the textblox is now the selected language
//decide what the contents are based on the selection
if (selection == "English")
translation.Text = "Something in English";
else if (selection == "Hindi")
translation.Text = "Something in Hindi";
else if (selection == "German")
translation.Text = "Something in German";
//etc
}
When you go to the next page, this allows you to create your page based on the selected item. This image demonstrates this:
Alternatively, you can solve your problem by creating a page for every possible language:
private void Continue(object sender, RoutedEventArgs e)
{
if(selection != null)
{
if(selection == "English")
this.Frame.Navigate(typeof(EnglishPage));
else if(selection == "Hindi")
this.Frame.Navigate(typeof(HindiPage));
//and so on
}
}
I prefer to do it this way because it's a lot simpler.
Edit: I see Items in the property box but I'm not aware of how to use it to add combo box items. This is the way that I usually see it done:
Of course you'll need to replace MainPage with your page (if it's not already named MainPage).
Another edit:
If you added the items via the properties panel, you have to access the Content. Use this instead, if you want:
string selection = null;
private void ComboBox1_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
if (ComboBox1.SelectedIndex != -1)
{
//selection = ComboBox1.SelectedItem.ToString();
selection = (ComboBox1.SelectedItem as ComboBoxItem).Content.ToString();
}
}

Related

how to check whether items present in list box & how to check list box has duplicates? in csharp

private void button1_Click(object sender, EventArgs e)
{
listBox1.Items.Add(textBox1.Text);
}
private void button2_Click(object sender, EventArgs e)
{
string val = listBox1.Text.Trim();
if (listBox1.Items.Contains(val)) {
listBox1.Items.RemoveAt(listBox1.SelectedIndex);
}
else
{
MessageBox.Show("There is no items present");
}
}
elements are entered from text box to list box, If entered the same data,. how to check? or msg box should display and
while deleting items from the list box if there is no items how to i get to know.
You can check if the value entered in the textbox is already in the listbox or not:
bool listContainsItem = Listbox.Items.Any(item => item.Value == textboxValue);
if(listContainsItem)
{
// ... item is in listbox, do your magic
}
else
{
// ... item is not in listbox, do some other magic
}
You can do this in the Onchange event of your textbox, or when clicking a button, ... give us more context so we can provide you a better solution.
You can use a HashSet as data source to make sure your list contains unique elements.
In example :
HashSet<string> ListBoxSource = new HashSet<string>();
private void button2_Click(object sender, EventArgs e)
{
string val = listBox1.Text.Trim();
// ListBoxSource.Add(val) Return true if val isn't present and perform the adding
if (ListBoxSource.Add(val))
{
// DataSource needs to be a IList or IListSource, hence the conversion to List
listBox1.DataSource = ListBoxSource.ToList();
}
else
{
MessageBox.Show("Item is already in list");
}
}
You may check for duplicated item by looping through each item in the list to be compared with name of item to be added when add button is clicked:
private void addBtn_Click(object sender, EventArgs e)
{
bool similarItem = false;
if (!String.IsNullOrEmpty(itemText.Text.Trim()))
{
foreach (string listItem in itemListBox.Items)
{
if (listItem == itemText.Text)
{
MessageBox.Show("Similar item detected");
similarItem = true;
break;
}
}
if(!similarItem)
itemListBox.Items.Add(itemText.Text);
}
}
To prompt user when delete button is clicked when there is no item, the selected index will be -1, u may use that as the condition to prompt user:
private void deleteBtn_Click(object sender, EventArgs e)
{
if (itemListBox.SelectedIndex > -1)
itemListBox.Items.RemoveAt(itemListBox.SelectedIndex);
else
MessageBox.Show("No item exist in the list box, operation fail");
}

CopyListBoxItem from one ListBox to another

I have two ListBoxes. I want to copy SelectedItem from the first ListBox into Second one.
Why this code does not work ?
private void frm_addDispatchBoard2_Load(object sender, EventArgs e)
{
using(propertiesManagementDataContext db = new propertiesManagementDataContext())
{
var Buildings = db.Buildings.Select(q => new { q.BuildingLandNumber, q.BuildingId });
listBox_allBuildings.DataSource = Buildings;
listBox_allBuildings.DisplayMember = "BuildingLandNumber";
listBox_allBuildings.ValueMember = "BuildingId";
}
}
private void btn_addBuilding_Click(object sender, EventArgs e)
{
if(listBox_allBuildings.SelectedIndex > 0)
{
listBox_selectedBuildings.Items.Add(listBox_allBuildings.SelectedItem);
}
}
The result I got:
try this I am not sure why you are looking for a Contains but if you really need that look at the difference between SelectedValue and SelectedItem
Use this code right here as a test to see if the expected value shows up in a MessageBox
string selected = listBox_allBuildings.GetItemText(listBox_allBuildings.SelectedValue);
MessageBox.Show(selected);
this should help you to see the values in the Listbox on the right
private void btn_addBuilding_Click(object sender, EventArgs e)
{
if(listBox_allBuildings.SelectedIndex != -1)
{
var selected = listBox_allBuildings.GetItemText(listBox_allBuildings.SelectedValue);
listBox_selectedBuildings.Items.Add(selected);
}
}

ButtonClick to get an Object on SelectionChanged event

I have a SelectionChanged event and works perfectly, but I want to figure out how to "catch" this selected item at the click of a button they need to pass it as parameter to another page and edit this Item. Here's the current code and button SelectionChanged I still implemented because this is what I need.
private void listCarros_SelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e)
{
ListBox listBox = sender as ListBox;
if (listBox != null && listBox.SelectedItem != null)
{
//pega o Carro que foi selecionado
Carro sCar = (Carro)listBox.SelectedItem;
btnEditCar.IsEnabled = true;
btnDeleteCar.IsEnabled = true;
}
else
{
btnEditCar.IsEnabled = false;
btnDeleteCar.IsEnabled = false;
}
}
I need to edit the selectedItem on this button:
private void btnEditCar_Click(object sender, EventArgs e)
{
//Here I need access to the selectedItem on SelectionChanged event.
}
If you could also tell me how to pass the object as parameter would be perfect.
You can do this with binding also
1.Bind ListBoxItem(Carro Object) to the tag of "btnEditCar" in xaml.
Xaml should be like this
<Button Name="btnEditCar" OnClick="btnEditCar_Click" Tag="{Binding}"/>
and now in
private void btnEditCar_Click(object sender, EventArgs e)
{
Carro sCar=(Carro)((sender as FrameworkElement).Tag)
}
This is the good practice,creating a class variable only for temporary purpose is hack
To give a better idea on my comments. Creating a class level variable is like this:
Notice that sCar is declared outside the method, but within the class.
Carro sCar = new Carro();
private void listCarros_SelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e)
{
ListBox listBox = sender as ListBox;
if (listBox != null && listBox.SelectedItem != null)
{
sCar = (Carro)listBox.SelectedItem;
...
private void btnEditCar_Click(object sender, EventArgs e)
{
sCar.ProperyYouWantToChange = "Stuff I want to change"
}

C# - Highlight wrong controls when validating

I am trying to validate windows form with try catch and so far I succeeded. My goal is when someone forgot to fill the gap or put in incorrect entry, catch returns messagebox with a warning. Now I also have Validating event on every control I want to validate so when somebody leave it empty or in incorrect format it will show the error next to the control. That seems ok so far (for me, at least) but my issue is, that if user doesn't even click to one box it only shows message box, but it won't highlight wrong controls.
Below is my code:
private void createButton_Click(object sender, EventArgs e)
{
try
{
Book newBook = new Book(titleBox.Text, authBox.Text, Convert.ToInt32(yearBox.Text), Convert.ToInt32(editBox.Text), pubComboBox.Text, descBox.Text);
bookList.Add(newBook);
booklistListBox.DataSource = bookList;
}
catch (FormatException)
{
MessageBox.Show("You probably missed a gap or put in incorrect form");
}
}
and those validating events:
private void titleBox_Validating(object sender, CancelEventArgs e)
{
if (titleBox.Text.Trim() == String.Empty)
{
errorProvider.SetError(titleBox, "Title is required");
e.Cancel = true;
}
else
{
errorProvider.SetError(titleBox, "");
}
}
private void authBox_Validating(object sender, CancelEventArgs e)
{
if (authBox.Text.Trim() == String.Empty)
{
errorProvider.SetError(authBox, "Author is required");
e.Cancel = true;
}
else
{
errorProvider.SetError(authBox, "");
}
}
private void yearBox_Validating(object sender, CancelEventArgs e)
{
if (yearBox.Text.Trim() == String.Empty)
{
errorProvider.SetError(yearBox, "Year is required");
e.Cancel = true;
}
else
{
errorProvider.SetError(yearBox, "");
}
}
private void editBox_Validating(object sender, CancelEventArgs e)
{
if (editBox.Text.Trim() == String.Empty)
{
errorProvider.SetError(editBox, "Edition is required");
e.Cancel = true;
}
else
{
errorProvider.SetError(editBox, "");
}
}
private void pubComboBox_Validating(object sender, CancelEventArgs e)
{
if (pubComboBox.Text.Trim() == String.Empty)
{
errorProvider.SetError(pubComboBox, "Publisher is required");
e.Cancel = true;
}
else
{
errorProvider.SetError(pubComboBox, "");
}
}
private void descBox_Validating(object sender, CancelEventArgs e)
{
if (descBox.Text.Trim() == String.Empty)
{
errorProvider.SetError(descBox, "Description is required");
e.Cancel = true;
}
else
{
errorProvider.SetError(descBox, "");
}
}
So is there way to, I don't know, change focus or something like that, forced with pressing the create button?
Thank You
Try using ValidateChildren():
private void createButton_Click(object sender, EventArgs e)
{
bool gotIssues = this.ValidateChildren();
if (gotIssues)
{
// someone didn't validate well...
}
}
So, the issue here is that you want to have it highlight in either of two scenarios:
1) When you leave the field and its contents are invalid (empty in this case)
2) When you click the create button and the field in question has invalid contents
And so I would create a single textBox_checkIfEmpty(object sender, EventArgs e) method:
private void textBox_checkIfEmpty(object sender, EventArgs e)
{
var asTb = sender as TextBox;
if (asTb != null && asTb.Text.Trim() == String.Empty)
{
errorProvider.SetError(asTb, "I'll leave it to you to abstract the error message appropriately");
e.Cancel = true;
}
else
{
errorProvider.SetError(asTb, "");
}
}
Then, you can set this method as the handler for your Validate event on your desired required controls, and you can also call the same method from the create button's handler, looping through the required TextBox instances and executing the method on each.
UPDATE
J. Hudler's ValidateChildren solution would be a more (developer) efficient tail to mine, as opposed to looping through the desired controls. That said, if the form has many children, and you only need to validate several, it might be helpful to loop still. Just depends on your specific scenario. My only other question is whether or not ValidateChildren is infinitely recursive, or if it only goes one level down (immediate children rather than all descendants).
the event validating for control call when the mouse click on the control and then leave it from the control. In your case when the user does not click on the control it will not trigger the validating event. U can do this by making your own function and call them on creat event.
private void button1_Click(object sender, EventArgs e)
{
textBox1_Validating(sender);
}
public void textBox1_Validating(object sender)
{
MessageBox.Show("validating");
errorProvider1.SetError(textBox1, "provide");
}

How can I refactor this C# code below?

I have 12 buttons in my Form1, and each button has a textbox next to it. The button event calls a method called dialogueOpen which handles getting the an object from form2 and placing a string value in a textbox.
How can I place the value returned in a textbox depending on what button the user clicked on? So if it is button1 a user clicked on, then the text returned should be placed in textbox1 and if it is button2 the user clicked on then the text returned should be placed in textbox2. The point is avoid using a string name to check as the buttons can all be called "browse".
Right now my code below does that but it is quite repetitive is there is a better of doing this?
private void dailogueOpen(String btnName)
{
if (listBox1.SelectedItem == null)
{
MessageBox.Show("Please Select a form");
}
else
{
var selectedItem = (FormItems)listBox1.SelectedItem;
var form2result = new Form2(myDataSet, selectedItem);
var resulOfForm2 = form2result.ShowDialog();
if (resulOfForm2 == DialogResult.OK)
{
switch (btnName)
{
case "btn1":
textBox1.Text = form2result.getValue();
break;
case "btn2":
textBox2.Text = form2result.getValue();
break;
case "btn3":
textBox3.Text = form2result.getValue();
break;
case "btn4":
textBox4.Text = form2result.getValue();
break;
case "btn5":
textBox5.Text = form2result.getValue();
break;
}
}
}
}
private void button1_Click(object sender, EventArgs e)
{
String name = "btn1";
dailogueOpen(name);
}
private void button2_Click(object sender, EventArgs e)
{
String name = "btn2";
dailogueOpen(name);
}
private void button3_Click(object sender, EventArgs e)
{
String name = "btn3";
dailogueOpen(name);
}
private void button4_Click(object sender, EventArgs e)
{
String name = "btn4";
dailogueOpen(name);
}
private void button5_Click(object sender, EventArgs e)
{
String name = "btn5";
dailogueOpen(name);
}
EDIT: I just noticed your event handlers. More refactoring ensues:
Yes, there is. You need to somehow associate textboxes to buttons. For example, create a dictionary like so:
Dictionary<Button, TextBox> _dict;
_dict[button1] = textBox1;
_dict[button2] = textBox2;
...
Use one event handler for all events:
private void button_click(object sender, EventArgs e)
{
dialogeOpen((Button)sender);
}
Change dialogueOpen to accept a Button instead of a string and
_dict[btn].Text = form2Result.getValue();
replace your eventhandlers to
private void ButtonClick(object sender, EventArgs e)
{
var button = sender as Button;
if (button == null) return;
String name = button.Text;// Tag, name etc
dailogueOpen(name);
}
1 You use the same delegate on all button
Nota (Thank's to Marty) : When You're in the Form Designer, select all buttons, and then assing then "Generic_Click" for all of them, or you can use code below.
this.btn1.Click += new System.EventHandler(Generic_Click); //the same delegate
this.btn2.Click += new System.EventHandler(Generic_Click);
this.btn3.Click += new System.EventHandler(Generic_Click);
....
private void Generic_Click(object sender, EventArgs e)
{
var control = (Button)sender;
if( control.Name == "btn1")
{
....
}
else if( control.Name == "btn2")
{
....
}
else if( control.Name == "btn3")
{
....
}
}
I would first use just one event handler for the buttons, it would look like this:
protected void ButtonClick(object sender, EventArgs e)
{
Button clickedButton = (Button) sender;
string selectedId = clickedButton.ID;
string[] idParameters = selectedId.Split('_');
string textBoxId = "textbox" + idParameters[1];
dailogueOpen(textBoxId);
}
What I did here is use a pattern for the names of the textboxes, so for instance if you have buttons with ids like: button_1 ,button_2, ..., button_n, you can infer what the corresponding textbox is.
If you click button_1, by spliting its id you'll know that its corresponding textbox is the one whose id is textbox1.
Then the dialogueOpen function would look like this:
private void dailogueOpen(string textBoxId)
{
if (listBox1.SelectedItem == null)
{
MessageBox.Show("Please Select a form");
}
else
{
var selectedItem = (FormItems)listBox1.SelectedItem;
var form2result = new Form2(myDataSet, selectedItem);
var resulOfForm2 = form2result.ShowDialog();
if (resulOfForm2 == DialogResult.OK)
{
TextBox textBox = (TextBox)this.Form.FindControl("MainContent").FindControl(textBoxId);
textBox.Text = resulOfForm2.getValue();
}
}
Where MainContent is the id of container where the textboxes are.
All in all:
I would use a pattern for button and texboxes id.
According to the button being clicked I infer its corresponding texbox id.
Then find the texbox and update its value.
You can have dictionary and one event method on all button clicks
Dictionary<Button, TextBox> dx = new Dictionary<Button, TextBox>;
private void ButtonClick(object sender, EventArgs e)
{
var button = sender as Button;
if (button == null) return;
dx[button].Text = form2result.getValue();
}
and constructor like this:
public ClassName()
{
dx.Add(button1, textBox1);
dx.Add(button2, textBox2);
dx.Add(button3, textBox3);
}
I think the first thing you can do is improve readability by removing the need for the switch statement:
private void dailogueOpen(TextBox textBox)
{
if (listBox1.SelectedItem == null)
{
MessageBox.Show("Please Select a form");
}
else
{
var selectedItem = (FormItems)listBox1.SelectedItem;
var form2result = new Form2(myDataSet, selectedItem);
var resulOfForm2 = form2result.ShowDialog();
if (resulOfForm2 == DialogResult.OK)
{
textBox.Text = form2result.getValue();
}
}
}
private void button1_Click(object sender, EventArgs e)
{
dailogueOpen(textBox1);
}
private void button2_Click(object sender, EventArgs e)
{
dailogueOpen(textBox2);
}
private void button3_Click(object sender, EventArgs e)
{
dailogueOpen(textBox3);
}
private void button4_Click(object sender, EventArgs e)
{
dailogueOpen(textBox4);
}
private void button5_Click(object sender, EventArgs e)
{
dailogueOpen(textBox5);
}
This then gives you a reasonable method signature to introduce the dictionary (suggested by two other people) to map Button to TextBox, which would in turn allow you to use a single event handler (suggested by two other people) for all buttons.
private void button_Click(object sender, EventArgs e)
{
Button button = sender as Button;
if (button == null) return;
String name = button.Text;// Tag, name etc
dailogueOpen(name);
}
private void dailogueOpen(String btnName)
{
if (listBox1.SelectedItem == null)
{
MessageBox.Show("Please Select a form");
}
else
{
var selectedItem = (FormItems)listBox1.SelectedItem;
var form2result = new Form2(myDataSet, selectedItem);
var resulOfForm2 = form2result.ShowDialog();
if (resulOfForm2 == DialogResult.OK)
{
SetTxt(btnName,form2result.getValue());
}
}
}
private void SetTxt(string btnName, string value)
{
int lenght = "Button".Length;
string index = btnName.Substring(lenght); //remove Button
TextBox t = (TextBox)this.Controls.Find("textBox" + index, true)[0];
if (t != null)
t.Text = value;
}

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