Say I had a ComboBox with these values:
Black
Red
Blue
And I have Red
currently selected. If the user t开发者_开发百科hen hits backspace and hits enter I am capturing the KeyDown
event of the ComboBox.
In this event I want to delete Red from the list of items in the ComboBox.
However, because the text of the ComboBox is blank by the time KeyDown
is called, the SelectedIndex
is -1.
Currently I have a workaround that looks like this:
private void myComboBox_SelectedIndexChanged(object sender, EventArgs e)
{
currentMyComboBoxIndex = myComboBox.FindStringExact(myComboBox.Text);
}
Which works.. but I was just wondering if there is a better way. It seems like this way could break somehow and it seems a bit messy. Is there no way to get the current index of the ComboBox without having to keep track of it with a member variable and updating it when the index changes?
Thank you.
The way you are doing is fine. You have to keep the selected index in memory because it returns -1 as the SelectedIndex when the text is deleted. You could take the index in this way too.
private void myComboBox_SelectedIndexChanged(object sender, EventArgs e)
{
currentMyComboBoxIndex = myComboBox.SelectedIndex;
}
You can use the following code to get the selected item of the combo box as an object:
ComboBox comboBox = new ComboBox();
// Initialize combo box
comboBox.Items.Add("Black");
comboBox.Items.Add("Red");
comboBox.Items.Add("Blue");
// Get selected one
string current = (string)comboBox.SelectedItem;
Also, the selected item can be easily removed by using one of the following lines of code:
// By item
comboBox.Items.Remove(comboBox.SelectedItem);
// By Index
comboBox.Items.RemoveAt(comboBox.SelectedIndex);
There is no inbuilt function to get the index for given value but you can find the index through this function.
Usage:
int cmbindex = CmbIdxFindByValue("YourValue", cmbYourComboBox);
Function:
private int CmbIdxFindByValue(string text, ComboBox cmbCd)
{
int c = 0; ;
DataTable dtx = (DataTable)cmbCd.DataSource;
if (dtx != null)
{
foreach (DataRow dx in dtx.Rows)
{
if (dx[cmbCd.ValueMember.ToString()].ToString() == text)
return c;
c++;
}
return -1;
}else
return -1;
}
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