I have 3 list boxes and when I have three things selected and click the delete button it deleted the text in the first list box but then gives a exception saying a value of -1 is not valid for index. This is my current code:
lstBoxOne.Items.RemoveAt(lstBoxOne.SelectedIndex);
lstBoxTwo.Items.RemoveAt(lstBoxTwo.SelectedIndex);
lstBoxThree.Items.RemoveAt(lstBoxThree.SelectedIndex);
wondered if theirs a way to delete all three selected text with a click of a button
Edit: I have now put image of full expection
Full exception
Edit 2: Here is an example with full code
namespace WindowsFormsApp1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void LstBoxOne_SelectedIndexChanged(object sender, EventArgs e)
{
var deleteD = lstBoxOne.SelectedIndex;
lstBoxTwo.SelectedIndex = deleteD;
lstBoxThree.SelectedIndex = deleteD;
}
private void BtnInsert_Click(object sender, EventArgs e)
{
lstBoxOne.Items.Add(this.txtOne.Text);
lstBoxTwo.Items.Add(this.txtTwo.Text);
lstBoxThree.Items.Add(this.txtThree.Text);
this.txtOne.Focus();
this.txtOne.Clear();
this.txtTwo.Focus();
this.txtTwo.Clear();
this.txtThree.Focus();
this.txtThree.Clear();
}
private void BtnDelete_Click(object sender, EventArgs e)
{
lstBoxOne.Items.RemoveAt(lstBoxOne.SelectedIndex);
lstBoxTwo.Items.RemoveAt(lstBoxTwo.SelectedIndex);
lstBoxThree.Items.RemoveAt(lstBoxThree.SelectedIndex);
}
private void LstBoxTwo_SelectedIndexChanged(object sender, EventArgs e)
{
var deleteD = lstBoxTwo.SelectedIndex;
lstBoxOne.SelectedIndex = deleteD;
lstBoxThree.SelectedIndex = deleteD;
}
private void LstBoxThree_SelectedIndexChanged(object sender, EventArgs e)
{
var deleteD = lstBoxThree.SelectedIndex;
lstBoxOne.SelectedIndex = deleteD;
lstBoxTwo.SelectedIndex = deleteD;
}
}
}
}
The problem is due to the SelectedIndexChanged event on lstBoxOne.
Inside of BtnDelete_Click, when you remove the selected item from lstBoxOne this causes lstBoxOne.SelectedIndex to change. This causes LstBoxOne_SelectedIndexChanged to fire BEFORE the item is removed from lstBoxTwo and lstBoxThree. When LstBoxOne_SelectedIndexChanged finishes and returns to BtnDelete_Click, lstBoxTwo.SelectedIndex and lstBoxThree.SelectedIndex are both -1 and the Exception is occurring due to passing -1 to RemoveAt.
private void LstBoxOne_SelectedIndexChanged(object sender, EventArgs e)
{
var deleteD = lstBoxOne.SelectedIndex;
lstBoxTwo.SelectedIndex = deleteD;
lstBoxThree.SelecteIndex = deleteD;
}
private void DeleteBtn_Click(object sender, EventArgs e)
{
lstBoxOne.Items.RemoveAt(lstBoxOne.SelectedIndex); //This line triggers the SelectedIndexChanged event on lstBoxOne.
// By the time we get back to this function, lstBoxTwo and lstBoxThree have had
// their SelectedIndex set to -1. That is what is causing the exception to occur.
lstBoxTwo.Items.RemoveAt(lstBoxTwo.SelectedIndex); //Ooops! lstBoxTwo.SelectedIndex was set to -1 in LstBoxOne_SelectedIndexChanged.
}
A simple way to correct this would be to store the selected index of each ListBox before trying to remove any items. Also, protect yourself by checking for -1.
private void DeleteBtn_Click(object sender, EventArgs e)
{
int lstBoxOneIdx = lstBoxOne.SelectedIndex;
int lstBoxTwoIdx = lstBoxTwo.SelectedIndex;
int lstBoxthreeIdx = lstBoxThree.SelectedIndex;
if (lstBoxOneIdx > -1)
{
lstBoxOne.Items.RemoveAt(lstBoxOneIdx);
}
if (lstBoxTwoIdx > -1)
{
lstBoxTwo.Items.RemoveAt(lstBoxTwoIdx);
}
if (lstBoxThreeIdx > -1)
{
lstBoxThree.Items.RemoveAt(lstBoxThreeIdx);
}
}
Related
I'm having trouble passing values entered in form2(citacao) to form1(principal).
Principal.cs (form1)
richEditControl1.Document.AppendText(citacao.valor_edit[0]);
Citacao.cs (form2)
public string[] valor_edit = new string[3];
private void simpleButton2_Click(object sender, EventArgs e)
{
valor_edit[0] = memoEdit1.Text;
valor_edit[1] = comboBox1.SelectedItem.ToString();
valor_edit[2] = textEdit1.Text;
}
But when I click the button nothing happens , the values are not inserted into the richedit I like it.
I already have this on form (Pass DataGrid to ComboBox)
Form1 (principal)
private void barButtonItem1_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e)
{
citacao cita = new citacao(this);
cita.Show();
}
form2(citação)
public citacao(principal gridForm)
{
InitializeComponent();
frm1 = gridForm;
}
// LOAD ALL FONTS (Referencias);
private void citacao_Load(object sender, EventArgs e)
{
comboBox1.Items.Clear();
foreach (DataGridViewRow row in frm1.DataGridView1.Rows)
{
comboBox1.Items.Add(row.Cells[0].Value.ToString());
}
comboBox1.SelectedIndex = 0;
}
let's see whether I understood your situation :)
declare your variable in Form 1 as a class variable
private citacao cita;
then initialize it in the button press event
private void barButtonItem1_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e)
{
cita = new citacao(this);
// subscribe to the closing event
cita.FormClosing += form_FormClosing;
cita.Show();
}
// when Form 2 will be closed you can execute your important line in the event
void form_FormClosing(object sender, FormClosingEventArgs e)
{
// BUT! you have to use the variable name!
richEditControl1.Document.AppendText(cita.valor_edit[0]);
}
EDIT:
Ok after looking at the entire code:
please remove the button3! and this entire code:
private void button3_Click(object sender, EventArgs e)
{
cita = new citacao(this);
richEditControl1.Document.AppendText(citacao.valor_edit); // this line is the problem!
}
The function AppendText probably needs a string as parameter and you give the entire array!
If you subscribe to the closing event in Form1 / principal and also implement
the event, your data will be transmitted automatically as soon as the Form 2 disappears from the screen :)
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);
}
}
I want my checkedlistbox to expand to a certain size when the mouse enters and then go back to a its original size after mouse leaves. Below is the code is have. However, I receive an error when i have another program selected and my mouse goes over the checkedlistbox while the application is not active.
Any suggestions on how to fix?
private void checkedListBox1_MouseEnter(object sender, EventArgs e)
{
Search.ActiveForm.Height = 552;
checkedListBox1.Height = 130;
}
private void checkedListBox1_MouseLeave(object sender, EventArgs e)
{
Search.ActiveForm.Height = 452;
checkedListBox1.Height = 34;}
Error Code - Object Reference not set to an instance of an object.
Try this
private void checkedListBox1_MouseEnter(object sender, EventArgs e)
{
checkedListBox1.Size = new Size(Width,Height);
}
This of course would work so that no exception is thrown, but I hope it's also what you want:
private void checkedListBox1_MouseEnter(object sender, EventArgs e)
{
if(Search.ActiveForm == null) return;
Search.ActiveForm.Height = 552;
checkedListBox1.Height = 130;
}
private void checkedListBox1_MouseLeave(object sender, EventArgs e)
{
if(Search.ActiveForm == null) return;
Search.ActiveForm.Height = 452;
checkedListBox1.Height = 34;
}
I have been working on this project for a few days, it’s a C# Windows Visual Studio 2010 form and I have been posting different questions that relate to the same project; as I was told to post different questions instead on having them all in the same post. So this is the project: create a form with two ListBoxes—one contains at least four font names and the other contains at least four font sizes. Let the first item in each list be the default selection if the user fails to make a selection. Allow only one selection per ListBox. After the user clicks a button, display "Hello" in the selected font and size.
This time I’m having a problem getting the message in the textbox to display according to the font type and size that the user selected. Here is where I’m at in the coding:
public Form1()
{
InitializeComponent();
//populate listbox1
listBox1.Items.Add("Arial");
listBox1.Items.Add("Calibri");
listBox1.Items.Add("Times New Roman");
listBox1.Items.Add("Verdana");
//populate listbox2
listBox2.Items.Add("8");
listBox2.Items.Add("10");
listBox2.Items.Add("12");
listBox2.Items.Add("14");
this.listBox1.SelectedIndexChanged += new System.EventHandler(this.listBox1_SelectedIndexChanged);
listBox1.SelectedIndex = 0; // <--- set default selection for listBox1
this.listBox2.SelectedIndexChanged += new System.EventHandler(this.listBox2_SelectedIndexChanged);
listBox2.SelectedIndex = 0; // <--- set default selection for listBox2
}
private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
{
textBox1.Text = listBox1.SelectedItem.ToString();
}
private void listBox2_SelectedIndexChanged(object sender, EventArgs e)
{
textBox1.Text = listBox2.SelectedItem.ToString();
}
private void textBox1_TextChanged(object sender, EventArgs e)
{
textBox1.Text = "Hello!";
}
private void button1_Click(object sender, EventArgs e)
{
}
}
}
Now I'm trying to elicit a call from a button clicked that will display the message "Hello" in the user’s choice of font and font size. Any suggestions would be greatly appreciated.
remove this method:
private void textBox1_TextChanged(object sender, EventArgs e)
{
textBox1.Text = "Hello!";
}
in the button_click event of your button, add this :
private void button1_Click(object sender, EventArgs e)
{
textBox1.Text = "hello";
textBox1.Font = new Font(listBox1.SelectedItem.ToString(), Convert.ToInt32(listBox2.SelectedItem.ToString()));
}
you might want to remove the selectedindexchanged methods in your code if you are going to use a button tho. depends on what you want.
edit:
public Form2()
{
InitializeComponent();
listBox1.Items.Add("Arial");
listBox1.Items.Add("Calibri");
listBox1.Items.Add("Times New Roman");
listBox1.Items.Add("Verdana");
listBox2.Items.Add("8");
listBox2.Items.Add("10");
listBox2.Items.Add("12");
listBox2.Items.Add("14");
listBox1.SelectedIndex = 0;
listBox2.SelectedIndex = 0;
}
private void button1_Click(object sender, EventArgs e)
{
textBox1.Text = "hello";
textBox1.Font = new Font(listBox1.SelectedItem.ToString(), Convert.ToInt32(listBox2.SelectedItem.ToString()));
}
if you just use the above code everything should work as you want it to. I tried it out myself and it's working fine for me
This was my final submission. Thanks for all of the advice guys.
public Form1()
{
InitializeComponent();
//populate listbox1
listBox1.Items.Add("Arial");
listBox1.Items.Add("Calibri");
listBox1.Items.Add("Times New Roman");
listBox1.Items.Add("Verdana");
listBox1.SelectedIndex = 0; // <--- set default selection for listBox1
//populate listbox2
listBox2.Items.Add("8");
listBox2.Items.Add("10");
listBox2.Items.Add("12");
listBox2.Items.Add("14");
listBox2.SelectedIndex = 0; // <--- set default selection for listBox2
}
private void button1_Click(object sender, EventArgs e)
{
textBox1.Text = "hello";
textBox1.Font = new Font(listBox1.SelectedItem.ToString(), Convert.ToInt32(listBox2.SelectedItem.ToString()));
}
private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
{
}
private void listBox2_SelectedIndexChanged(object sender, EventArgs e)
{
}
private void textBox1_TextChanged(object sender, EventArgs e)
{
}
}
}
I have found the closest reference of my problem on these links:
ComboBox has its old value after Clear()
Why selected index fires only once the Index of the ListItem is changed?
I have 4 comboboxes: cmbcountry, cmbstate, cmbdistrict and cmbcity. cmbcountry populates on load event by GetCountry() method. cmbstate populates by GetState(countryid) method, which takes cmbcountry's selectedvalue as argument and returns a list of relevant states and so on for cmbdistrict and cmbcity...
Problem is on selecting different item in cmbState, cmbDistrct is not populating with the proper items.
.E.g. states :"madhya pradesh", "Utter pradesh" , "Rajsthan"
For "Rajsthan", cmbdistrict is populating with relavent value, but for "Utter pradesh", cmbdistrict still has old value.
Here is the relevant code:
private void TestForm1_Load(object sender, EventArgs e)
{
cmbCountry.ItemSource = Lookups.Lookup.GetCountries();
}
private void cmbCountry_SelectionChangeCommitted(object sender, EventArgs e)
{
cmbState.Text = "";
cmbState.Clear();
cmbState.SelectedIndex = -1;
cmbState.SelectedItem = null;
//cmbState.Items.Clear();
int countryId = Convert.ToInt32(cmbCountry.SelectedValue);
cmbState.ItemSource = Lookups.Lookup.GetStates(countryId);
}
private void cmbState_SelectionChangeCommitted(object sender, EventArgs e)
{
cmbDistrict.Text = "";
cmbDistrict.Clear();
cmbDistrict.SelectedIndex = -1;
cmbDistrict.SelectedItem = null;
//cmbDistrict.Items.Clear();
int stateId = Convert.ToInt32(cmbState.SelectedValue);
cmbDistrict.ItemSource = Lookups.Lookup.GetDistricts(stateId);
}
private void cmbDistrict_SelectionChangeCommitted(object sender, EventArgs e)
{
cmbCity.Text = "";
cmbCity.Clear();
cmbCity.SelectedIndex = -1;
cmbCity.SelectedItem = null;
//cmbCity.Items.Clear();
int DistrictId = Convert.ToInt32(cmbDistrict.SelectedValue);
cmbCity.ItemSource = Lookups.Lookup.GetCities(DistrictId);
}
private void cmbBank_SelectionChangeCommitted(object sender, EventArgs e)
{
int bankId = Convert.ToInt32(cmbBank.SelectedValue);
cmbControlBranch.ItemSource = Lookups.Lookup.GetBranches(bankId);
}
I have all above methods to clear previous data in comboboxes ...and items.clear() is giving an error if i am using it.
Please tell me if there is any other relevant reference which I am missing .