I'm pretty new here.
I have a form, and want to check if the user filled it in correctly. In the form there's a combo box; how can I build the "if" statement for checking whether the user picked an item from it ?
P.S. Sorry for my bad English, it's not my mother tongue. :)
Use:
if(comboBox.SelectedIndex > -1) //somthing was selected
To get the selected item you do:
Item m = comboBox.Items[comboBox.SelectedIndex];
As Matthew correctly states, to get the selected item you could also do
Item m = comboBox.SelectedItem;
Here is the perfect coding which checks whether the Combo Box Item is Selected or not
if (string.IsNullOrEmpty(comboBox1.Text))
{
MessageBox.Show("No Item is Selected");
}
else
{
MessageBox.Show("Item Selected is:" + comboBox1.Text);
}
You seem to be using Windows Forms. Look at the SelectedIndex or SelectedItem properties.
if (this.combo1.SelectedItem == MY_OBJECT)
{
// do stuff
}
if (comboBox1.SelectedIndex == -1)
{
//Done
}
It Works,, Try it
if (combo1.SelectedIndex > -1)
{
// do something
}
if any item is selected selected index will be greater than -1
You can try
if(combo1.Text == "")
{
}
I've found that using this null comparison works well:
if (Combobox.SelectedItem != null){
//Do something
}
else{
MessageBox.show("Please select a item");
}
This will only accept the selected item and no other value which may have been entered manually by the user which could cause validation issues.
Related
I need to check, particular value whether available in the loaded dropdown list data source, How to do it?
Here is the code which I tried and it works fine, but is there any simple way to find it?
if (ddlcountry.Items.Contains(ddlcountry.Items.FindByValue(drJob["Country"].ToString())) == true)
{
ddlcountry.SelectedValue = drJob["Country"].ToString(); //if available it assigns the value
}
Following is much simpler:
ListItem item = ddlcountry.Items.FindByValue(drJob["Country"].ToString());
if(item != null)
ddlcountry.SelectedValue = item.Value;
I have created a ComboBox with three values. I wanted that a message box opens when no item is selected so I tried this:
if (comboBox1.SelectedItem == null)
{
MessageBox.Show("Please select a value");
return;
}
That works fine but only if I click into the field in the combobox. When I dont touch it, the program will start without message box. Whats wrong?
if (string.IsNullOrEmpty(comboBox1.Text)) or if (comboBox1.SelectedIndex == -1)
Use
if (comboBox1.SelectedIndex == -1)
{
MessageBox.Show("Please select a value");
return;
}
Note: SelectedIndex will be set to -1 when SelectedValue is blank ONLY when FormattingEnabled is true. See here.
The code should work. Although I will also set SelectedIndex as well......
if (this.comboBox1.SelectedItem == null || this.comboBox1.SelectedIndex == -1)
you mean "When I dont touch it, the program will start without message box. Whats wrong?" is there any code related with "touch it"
Check the selected index value of dropdown equals -1
if (Comboboxid.SelectedIndex == -1){
MessageBox.Show("Your message.");
}
Ithink this is the one :
if(comboBox.SelectedItems==null) //or if(comboBox.SelectedItems==-1)
{
//show no item was selected from comboBox
}
or
if(comboBox.SelectedItems.Count==0)
{
//message no items selected
}
A ComboBox displays a text box combined with a ListBox, which enables the user to select items from the list or enter a new value. Conditionally testing SelectedItem or SelectedIndex will not handle the case of the user entering a new value from another input device like a keyboard. Use string.IsNullOrEmpty(comboBox1.Text) to handle all input/selection cases.
try this is the :
if ((comboBox.SelectedValue == null) || string.IsNullOrEmpty(comboBox.Text))
{
//message no items selected
}
I am trying to check that an item doesn't already exist in a list box before I add the new item.
if (TeamNameTextBox.Text != "")
{
if (TeamNameListBox.Items.FindByValue(TeamNameListBox.Text) == null)
{
TeamNameListBox.Items.Add(TeamNameTextBox.Text);
TeamNameTextBox.Text = "";
int teamCountUpdate = TeamNameListBox.Items.Count;
if (teamCountUpdate == 1)
{
TeamCount.Text = teamCountUpdate.ToString() + " Team";
}
else
{
TeamCount.Text = teamCountUpdate.ToString() + " Teams";
}
}
else
{
AddTeamSeasonError.Text = "This team has already been added";
}
}
else
{
AddTeamSeasonError.Text = "Please select a team";
}
I have got it to check if the text box is blank, but I need to check that the item a user is trying to add is not already in the the list box.
I have tried the line:
if (TeamNameListBox.Items.FindByValue(TeamNameListBox.Text) == null)
But that doesn't work, any suggestions on how I can do the check?
Use this:
if (!TeamNameListBox.Items.Contains(TeamNameTextBox.Text))
TeamNameListBox.Items.Add(TeamNameTextBox.Text);
think you should at least try to use TeamNameTextBox instead of TeamNameListBox as argument
if (TeamNameListBox.Items.FindByValue(TeamNameTextBox.Text) == null)
I suppose you mean
// search if the textbox value is found in the list. this comment shouldn't be part of the code
if (TeamNameListBox.Items.FindByValue(TeamNameTextBox.Text) == null)
instead of
if (TeamNameListBox.Items.FindByValue(TeamNameListBox.Text) == null) // code from question
EDIT: There is no need to put the name of the type of the control next to the variable.
i.e. instead of TeamNameListBox, use teamNames. And, instead of TeamNameTextBox, use teamName.
I have simple WinForms application in C# which has two controls: combobox1 and button. I would like to find out if there are any items in combobox1.
I have tried this, but it only tells me if there is a selected item:
if (combobox1.Text != ""))
{
MessageBox.Show("Combo is not empty");
}
Double click on your button in the Form and insert this code inside the click event handler : `
//this code should work
if (comboBox1.Items.Count == 0)
{
MessageBox.Show("Your combo is empty");
}
`
I use
if (comboBox1.SelectedItem!=null)
{
MessageBox.Show("Combo is not empty");
}
to determine if something is selected
And I use this to determine if the comboBox has any items.
if (comboBox1.Items.Count > 0)
{
MessageBox.Show("Your combo is not empty");
}
If no item selected/Present, then SelectedIndex property returns -1.
if (combobox1.SelectedIndex == -1)
//no item selected/present
Well, I am sure if you check out ComboBox class on MSDN: http://msdn.microsoft.com/en-us/library/system.windows.forms.combobox_properties, it'd benefit you.
Also, personally I wouldn't tend to use selectedIndex or selectedItem property, as there can be a case where item collection is not empty but none of any items are actually selected. Use items.count is a better way to decide if item collection is empty or not.
if (ComboBox.Items!=null && ComboBox.Items.Count>0)
{
//have some item
}
and if you need to know how many item have Use
string Count = ComboBox.Items.Count;
In Details View for the ListView Control, how can I do something like this, in the simplest way?
if(listView1.SelectedItem belongs to listView1.Groups["BaseballGroup"])
{
MessageBox.Show("The selected item is inside the Baseball Group");
}
Actually there's no property SelectedItem but a list of SelectedItems, then:
if(listView1.SelectedItems[0].Group == listView1.Groups["BaseballGroup"])
{
//...
}
N.B.
Check if something is selected (SelectedItems.Count > 0) to do SelectedItems[0] safely.
Perhaps you could try
listView1.Groups["BaseballGroup"].Contains(listView1.SelectedItem.ToString())