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C# combobox dropdown

I Want my combobox to drop down when i press the textfield and the dropdown symbol
I have done this:
private void comboBoxOpretKomponentLevel_Enter(object sender, EventArgs e)
{
if (comboBoxOpretKomponentLevel.SelectedIndex <= 0)
{
comboBoxOpretKomponentLevel.Text = null;
}
comboBoxOpretKomponentLevel.Focus();
comboBoxOpretKomponentLevel.DroppedDown = true;
}
The .Droppeddown = true makes it work if text is selected ("Select Product")
But when the dropdown symbol of dropbox is pressed - the droppeddown goes false again.
How do I make this work?
And as far as I know I cant use DropDownList because i can´t have my ("Select Product") Text.

I would simply use the MouseClickevent. Since you're question is too broad I only have this piece of code that may help you.
What it does is that only if you click the ComboBox or any controller regarding that ComboBox it is going to open the dropdownlist. To close it simply click on the Form_Load event and it will idle the dropdownlist
private void comboBoxOpretKomponentLevel_MouseClick(object sender, MouseEventArgs e)
{
//This piece will dropdown the combobox once you click it.
comboBoxOpretKomponentLevel.DroppedDown = true;
comboBoxOpretKomponentLevel.Focus();
}
private void YourForm_Click (object sender, EventArgs e)
{
//This piece will simply close the dropdown from your combobox and use the selected value.
comboBoxOpretKomponentLevel.DroppedDown = false;
}
Hope it helps, otherwise simple reformulate your question so we can help you.

check dropdown menu if matches

Long story short: There are specific tags given (like Pop, Rock, Metal) and the User should write into a textbox and every time he adds a char the given tags are checked if one (or more) matches. At the moment I'm using a combobox with the following code:
private void EnterComboBox_TextChanged(object sender, EventArgs e)
{
List<string> AllTags = new List<string>();
AllTags.Add("Pop");
if (AlleTags[0].ToLower().StartsWith(EnterComboBox.Text.ToLower()))
{
EnterComboBox.Items.Clear();
EnterComboBox.Items.Add("Pop");
EnterComboBox.DroppedDown = true;
}
}
this is working fine but the problem is, that after the first char entered the dropbox drops down and the entered text is marked and will be overwritten when a new char is entered. Any ideas how I could fix this? Every idea is welcome it doesn't have to be a combo box :)!
Edit:
After some more (detailed) research I realized I could explain it like this: Basically I want the combobox the behave like the search-bar from google. The users enters letters and in the dropdown menu are autocomplete suggestions
At the moment I solved it like this:
I placed a textbox in front of a combobox so that only the arrow of the combobx is visible and if you click on it you automatically write in the textbox.
public Form1()
{
InitializeComponent();
EingabeTextBox.AutoSize = false;
EingabeTextBox.Size = new Size(243, 21); //the size of the combobox is 260;21
}
private void EingabeTextBox_TextChanged(object sender, EventArgs e)
{
EingabeComboBox.Items.Clear();
List<string> AlleTags = new List<string>();
AlleTags.Add("Example");
if (AlleTags[0].ToLower().StartsWith(EingabeTextBox.Text.ToLower()))
{
EingabeComboBox.Items.Add(AlleTags[0]);
EingabeComboBox.DroppedDown = true;
}
}
For me it would work like this. I hope I can help someone else with this too, but I am still open for any better ideas :)!

Changing the ComboBox entries while typing into it obviously creates undesired interferences. Instead combine a TextBox and a ListBox.
private bool changing;
private void TextBox_TextChanged(object sender, EventArgs e)
{
if (!changing) {
changing = true;
try {
// manipulate entries in the ListBox
} finally {
changing = false;
}
}
}
private void ListBox_IndexChanged(object sender, EventArgs e)
{
if (!changing) {
changing = true;
try {
// Put selected entry into TextBox
} finally {
changing = false;
}
}
}
The changing guard makes sure that the ListBox does not influence the TextBox while you are entering text into the TextBox and vice versa.
The try-finally ensures that the guard will be reset in any circumstances, even if an exception should occur.

How can I manage overlapping DropDownBox drawers?

Most of my dropdown boxes use the SuggestAppend property, meaning when you start typing in the box, it will make a shortlist of the items that match your case. However, if I do this after opening the drawer, this happens:
I have tried using this method, but it closes both instead of just one:
private void cmbLoc_TextChanged(object sender, EventArgs e)
{
if (cmbLoc.Text != "")
{
cmbLoc.DroppedDown = false;
}
}
I am trying to have it so that when I type something into the text box, the original dropdown will disappear, and the SuggestAppend draw will appear. How can I manage this?

It worked if I used KeyDown. Try and tell if that helps
private void cmbLoc_KeyDown(object sender, KeyEventArgs e)
{
var comboBox = (ComboBox)sender;
comboBox.DroppedDown = false;
}

How to get ListBox to load after selecting ComboBox value?

Working in VS 2012, WinForms, C#...
I have a ListBox I would like to populate depending upon the value selected in a ComboBox. I've tested my SQL Query and it works, but I'm getting a weird problem where, when I run my routines, my ComboBox comes up empty, as well as my ListBox. When I comment out the code in my cb_Session_SelectedValueChanged routine, my CB and LB load just fine, but when it's not commented out is when my LB and CB end up blank.
This is what I have:
private void cb_Session_SelectedValueChanged(object sender, EventArgs e)
{
listbox_Sessions.Visible = true;
LoadSessionListbox();
}
private void LoadSessionListbox()
{
int tempID = Convert.ToInt32(cb_Session.SelectedValue);
// Code here to load listbox, which works without above routine.
}
Am I missing something? Why are my CB and LB blank with that first routine added?
[EDIT]:
I put the routines which were in SelectedValueChanged in a MouseClick event and it works, but not when I want it to... You have to click a couple times to get it to re-load with the correct ID. I feel like I'm getting closer, but still not the right event.

Try this:
private void cb_Session_SelectedValueChanged(object sender, EventArgs e)
{
if(cb_Session.SelectedValue>-1)
{
listbox_Sessions.Visible = true;
LoadSessionListbox();
}
}

Figured it out!!
I ended up adding a simple if statement to my SelectedValueChanged routine, and it fixed everything!
private void cb_Sessions_SelectedValueChanged(object sender, EventArgs e)
{
listBox_Sessions.Visible = true;
if (cb_Sessions.SelectedValue != null)
LoadSessionListbox();
}
Works perfectly now.

Try in SelectedIndexChanged Event and follow
private void cb_Session_SelectedIndexChanged(object sender, EventArgs e)
{
if (cb_Session.SelectedValue == null) return;
if (cb_Session.SelectedIndex == -1) return;
listbox_Sessions.Visible = true;
LoadSessionListbox((int)cb_Session.SelectedValue);
}
private void LoadSessionListbox(int selectedValue)
{
//TODO: Do stuff
}

TextBox Example Into Datagridview

I have simple textbox example as below:
private void Form1_Load(object sender, EventArgs e)
{
textBox1.Text = "Apple";
}
private void textBox1_TextChanged(object sender, EventArgs e)
{
if (textBox1.Text.Length == 1)
{
if (textBox1.Text == "B" || textBox1.Text == "b")
{
textBox1.Text = "Ball";
}
}
}
By default textbox1 should return "Apple" on Form load but when I press "b" or "B" then it should return "Ball" on textbox1. I have a confusion on utilize it into datagridview. how can i do it in datagridview?.
Suppose I have One column on datagridview like below:
private void Form1_Load(object sender, EventArgs e)
{
DataGridViewColumn Particulars = new DataGridViewTextBoxColumn();
dataGridView1.Columns.Insert(0, Particulars );
}
If I have above column In datagridview1 than How to do I with datagridview1 which I have did with textbox?.

You might find it more straightforward to use the auto-complete functionality built-in to the textbox control, rather than trying to code for all possible scenarios yourself.
There are two important properties of the TextBox control that you must configure to enable its auto-completion functionality: AutoCompleteMode and AutoCompleteSource.
The AutoCompleteMode property allows you to choose how the textbox autocomplete function will look in action. You can choose between any of the AutoCompleteMode values
None Disables the automatic completion feature for the ComboBox and TextBox controls.
Suggest Displays the auxiliary drop-down list associated with the edit control. This drop-down is populated with one or more suggested completion strings.
Append Appends the remainder of the most likely candidate string to the existing characters, highlighting the appended characters.
SuggestAppend Applies both Suggest and Append options.
The AutoCompleteSource property allows you to specify the strings that you want the textbox to propose auto-completion with. In your case, you will probably want to specify a CustomSource, which requires you to set the AutoCompleteCustomSource property to a user-defined collection of strings—something like "Apple, Ball, ..." etc.
The DataGridViewTextBoxColumn simply hosts a standard TextBox control, so all of the auto-complete functionality it provides is already available to you for free. You can set the appropriate properties of this textbox by handling the EditingControlShowing event of your DataGridView, like so:
private void dataGridView1_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
{
//Create and fill a list to use as the custom data source
var source = new AutoCompleteStringCollection();
source.AddRange(new string[] {"Apple", "Ball"});
//Set the appropriate properties on the textbox control
TextBox dgvEditBox = e.Control as TextBox;
if (dgvEditBox != null)
{
dgvEditBox.AutoCompleteMode = AutoCompleteMode.Suggest;
dgvEditBox.AutoCompleteCustomSource = source;
dgvEditBox.AutoCompleteSource = AutoCompleteSource.CustomSource;
}
}
EDIT: If you'd prefer to keep the same behavior as you have in the original textbox example, you can just handle the TextChanged event for the DataGridViewTextBoxColumn. As I already explained above, the DataGridViewTextBoxColumn simply hosts a standard TextBox control, so it's fairly straightforward to add a handler for its TextChanged event and use the same code you had before:
private void dataGridView1_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
{
TextBox dgvEditBox = e.Control as TextBox;
if (dgvEditBox != null)
{
//Add a handler for the TextChanged event of the underlying TextBox control
dgvEditBox.TextChanged += new EventHandler(dgvEditBox_TextChanged);
}
}
private void dgvEditBox_TextChanged(object sender, EventArgs e)
{
//Extract the textbox control
TextBox dgvEditBox = (TextBox)sender;
//Insert the appropriate string
if (dgvEditBox.Text.Length == 1)
{
if (dgvEditBox.Text == "B" || dgvEditBox.Text == "b")
{
dgvEditBox.Text = "Ball";
}
}
}