How can I check that a combobox in winforms contains some value?
Is there any way of doing it without iterating through all items?
if (comboBox1.Items.Contains("some value"))
{
}
If the items are some custom object instead of strings you might need to override the Equals method.
int index = comboBox1.FindString("some value");
comboBox1.SelectedIndex = index;
http://msdn.microsoft.com/en-us/library/wxyt1t12.aspx#Y500
There's also FindStringExact http://msdn.microsoft.com/en-us/library/c440x2eb.aspx
The other answers didn't work for me.
This did:
if (comboBox1.Items.Cast<string>().Any(i => i == position))
{
// Items contains value
}
Hope this helps!
To find exact data from combo box we have to check with FindStringExact
int resultIndex = cbEmployee1.FindStringExact(item.Text);
Using the accepted answer did not work for me as it always returned false even though a check of the list show the value present. What I use is the FindStringExact method, as recommend by Louis and Amit. In this case its a value entered in the comboBox text box.
var index = comboBox1.FindStringExact(comboBox1.Text)
if(index > -1)
{
//Success followup code
}
Related
My goal is to actually make a guessing game, so I created two arrays with Mysql data called answers and questions. And what I want to do is take the value from the user and if it is true, for example my first answer 'fashion' matches the guess the user entered in the textbox, I want the label to write correct and continue with the next answer and try to find the next answer
My code returns true when I enter my values in the array into the textbox, but I want them to be in order. How do you think I can use the for loop. How do you think I can use the for loop to make an ordered comparison?
for (int i=0;i<cevaplar.Count;i++)
{
string tahmin = textBox1.Text;
if(cevaplar.Contains(tahmin))
{
label1.Text = "true";
continue;
}
else
{
label1.Text = "false";
break;
}
}
}
In your code you use "cevaplar.Contains(tahmin)". With contains you're checking if tahim can be found anywhere in your array, without taking any order in account.
The solution to your problem should be quite simple. Just don't use contains in this situation but use a simple indexer to compare the elements. Try the following:
Replace:
if(cevaplar.Contains(tahmin))
{
...
}
With
if(cevaplar[i] == tahim) //here you check only if the i'th element is matching.
{
...
}
Good luck!
Does anyone know how to set the dropdownUI value with a string in unity?
I know how to set it up with an int like these
public DropDown dropdown;
dropdown.value = 1;
However, what I want is to set the value with a given string.
Something like:
dropdown.value = "an Option";
Look at the documentation of Dropdown.value:
public int value;
The Value is the index number of the current selection in the Dropdown. 0 is the first option in the Dropdown, 1 is the second, and so on.
it is of type int so in short: you can't
You could however get the index from the available options itself using IndexOf:
// returns a list of the text properties of the options
var listAvailableStrings = dropdown.options.Select(option => option.text).ToList();
// returns the index of the given string
dropdown.value = listAvailableStrings.IndexOf("an Option");
you could do the same also in one line using FindIndex
dropdown.value = dropdown.options.FindIndex(option => option.text == "an Option");
We can't add string value to the dropdown value field. So if you need to show an option having the given string then use FindIndex option to find that option in the dropdown and then assign that index to the value field.
dropdown.value = dropdown.options.FindIndex(option => option.text == "an Option");
This answer was written under the assumption you wanted to set the text of a dropdown item. As setting the value as a string is impossible, since the value is of type int. See derHugo's answer for how you can get the index from an option.
dropdown.value does not actually represent the text is shows. instead value
is the index number of the current selection in the Dropdown. 0 is the
first option in the Dropdown, 1 is the second, and so on.
As described in the docs here
What you are looking for is Dropdown.itemText (docs)
Meaning to set the text in your dropdown item you'll have to do the following: dropdown.itemText = "an Option";
A more complete guide on how dropdown menu's work can be found in the Unity manual here
Basically i'm trying to make it so if the Selected Index from a listbox (for example lets say the selected index is "Server1") contains a number ("1") or a certain word ("Server") it would do a certain thing. For example: If the selected index from the listbox contains a number 1, it would enter 1 into a text box. If the selected index contains a number 2, it would open up a application, just for an example.
what i tried:
if (csrListBox.SelectedIndex = "1");
and:
{
List<string> items = ListBox.Items.Cast<string>().ToList();
foreach (string item in ListBox.Items)
{
Regex regex = new Regex(#"1");
Match match = regex.Match(item);
if (match.Success)
{
*Doing Something*
}
}
ListBox.DataSource = items;
}
Try this:
if (csrListBox.SelectedIndex == 1);
The second "=" sign matters - it states you're doing a boolean check instead of assigning value "1" to the value.
Mistake - You are assigning value.
Use compare operator ==. and SelectedIndex is int not string.
if (csrListBox.SelectedIndex == 1)
{
// Your code goes here.
}
I would suggest you work with ListBox item values instead of selectedIndex as the SelectedIndex can only be an integer value. Something like this linq query will return if the ListBox contains a certain value that is selected. This takes care of multi-selections too.
var myValue = "1";
bool listContainsItem = ListBox.Items.Any(item => item.Value == myValue && item.Selected);
I'm doing a project where "ToString" is being used as a method.
private void button1_Click(object sender, EventArgs e)
{
if(cboPlaneType.SelectedItem = "Generic")
{
}
else if (cboPlaneType.SelectedIndex = "Passenger")
{
}
else if (cboPlaneType.SelectedIndex = "Fighter Jet")
{
}
}
And in this case i'm not sure what to do. As you can see I've tried a few different option but with no avail. I've also tried
if((string)cboPlaneType.SelectedItem = "Generic")
And that didn't work.
**Edit
Just to point out, SelectedValue wasn't the correct answer.
ended up being "if((string)combobox.SelectedItem == "Generic")
The equality operator in c# is ==; = is an assignment operator.
SelectedIndex will return an int representing the zero-based position of the item that is selected. (I'm guessing it returns -1 when no item is selected.)
SelectedItem can be an object of any type; if it is not a string then you can't match it by comparing with a string.
Are you saying that the objects with which the ComboBox is populated override ToString()? You should still be able to use the result of that method for comparison, because it can only return a string. Otherwise, you might be able to use SelectedValue, but this depends on what kind of ComboBox you are using and how you have set it up.
SelectedIndex is an property of type Int32.
Maybe you want to use SelectedValue instead ?
I am using:
if (RadioButtonList_VolunteerType.SelectedItem != null)
or how about:
if (RadioButtonList_VolunteerType.Index >= 0)
or how about (per Andrew Hare's answer):
if (RadioButtonList_VolunteerType.Index > -1)
To those who may read this question, the following is not a valid method. As Keltex pointed out, the selected value could be an empty string.
if (string.IsNullOrEmpty(RadioButtonList_VolunteerType.SelectedValue))
Those are all valid and perfectly legitimate ways of checking for a selected value. Personally I find
RadioButtonList_VolunteerType.SelectedIndex > -1
to be the clearest.
In terms of readability they all lack something for me. This seems like a good candidate for an extension method.
public static class MyExtenstionMethods
{
public static bool HasSelectedValue(this RadioButtonList list)
{
return list.SelectedItem != null;
}
}
...
if (RadioButtonList_VolunteerType.HasSelectedValue)
{
// do stuff
}
The question revolves more around whether to check for null or check value of an int. Martin's great extension method could also be written:
public static bool HasSelectedValue(this ListControl list)
{
return list.SelectedIndex >= 0;
}
The MSDN documentation for a ListControl states:
Default for SelectedItem is null.
Default for SelectedIndex is -1.
So either are valid ways and both work. The question is which is the best way. I'm guessing SelectedIndex as it is a value type operation rather than reference type operation. But I don't have anything to back that up with.
I recommend:
RadioButtonList_VolunteerType.SelectedIndex>=0.
According to the Microsoft Documentation:
The lowest ordinal index of the selected items in the list. The default is -1, which indicates that nothing is selected.
string.IsNullOrEmpty(RadioButtonList_VolunteerType.SelectedValue) will not always work as you can have a ListItem with an empty value:
<asp:ListItem Value=''>This item has no value</asp:ListItem>