I'm new to c# and I'm now learning how to trigger events based on some form actions.
This is part of view:
private void comboGoodsName_TextChanged(object sender, EventArgs e)
{
controller.selectName(comboGoodsName.Text);
}
public void nameChanged(object sender, MeasurementEventArgs e)
{
comboGoodsName.TextChanged -= comboGoodsName_TextChanged;
comboGoodsName.Text = e.value;
comboGoodsName.TextChanged += comboGoodsName_TextChanged;
}
And this is part of controller:
public void selectName(string name)
{
model.Name = name.Split('|')[0].Trim();
if (name.Contains(" | "))
{
string code = name.Split('|')[1].Trim();
model.NameCode = code;
}
}
The scenario is as follows:
I want to have a ComboBox with some items in it (doesn't matter what's the source). Items are combination of name and code in following format: NAME | CODE. When I enter some text in ComboBox (type it in), comboGoodsName_TextChanged is triggered, which in turn calls selectName which sets model's property, which in turn raises an event which is observed by nameChanged. This works fine, as expected (puts NAME in ComboBox and CODE to TextBox - not shown as not relevant). Problem shows up when I select item from ComboBox drop-down list. When I select item, instead of showing NAME in ComboBox, I see NAME | CODE.
Edit: In the model, property is set correctly, which I confirmed by printing its value. So, issue is related only to displaying proper value in ComboBox.
Try this:
private void comboGoodsName_SelectedIndexChanged(object sender, EventArgs e)
{
// if combobox has selected item then continue
if (comboGoodsName.SelectedIndex > -1)
{
// split the selecteditem text on the pipe into a string array then pull the first element in the array i.e. NAME
string nameOnly = comboGoodsName.GetItemText(this.comboGoodsName.SelectedItem).Split('|')[0];
// handing off the reset of the combobox selected value to a delegate method - using methodinvoker on the forms main thread is an efficient to do this
// see https://msdn.microsoft.com/en-us/library/system.windows.forms.methodinvoker(v=vs.110).aspx
this.BeginInvoke((MethodInvoker)delegate { this.comboGoodsName.Text = nameOnly; });
}
}
Related
I have a combobox in which I can type in text and it suggests results based on list of items containing that text. Everything seems to be working fine, except when I type in the first letter, the combobox automatically selects the first item in the results list as can be seen in the screenshot (http://prntscr.com/pple6f). I need to press the key again to clear the text field and type in the proper name. Only then the results are correct (http://prntscr.com/pplekc)
I have the following method to check for combobox text update
private void comboBox1_TextUpdate(object sender, EventArgs e)
{
comboBox1.Items.Clear();
listNew.Clear();
var source = new AutoCompleteStringCollection();
foreach (var item in listOnit)
{
if (item.ToLower().Contains(this.comboBox1.Text.ToLower()))
{
listNew.Add(item);
}
}
comboBox1.Items.AddRange(listNew.ToArray());
comboBox1.SelectionStart = this.comboBox1.Text.Length;
Cursor = Cursors.Default;
comboBox1.DroppedDown = true;
}
AutoCompleteMode is set to None, same with AutoCompleteSource.
I need the combobox to start filtering the results as soon as I start typing, not having to press the same letter twice. Are there any other options/properties that I need to check?
i am trying to implement my own ComboBox class in C# because, untill 3.5 NET Framework (if i'm not mistaking) suggestion lookup is made with a "StartWith" function (i.e. if the list contains "Doe, John" and user types "John", that item is not displayed). Basically i'm adding or removing items on text change event, getting them from the initial content of the list. Everything works pretty fine for what i am looking for, the only issue is, when ComboBox is clicked out, an item is still being selected even though it is not equal to the inserted text. Following the example i did, i want that "Doe, John" is selected (and set as ComboBox.Text property) only if user clicked on it, if user just typed "John" and no item is strictly equal to it (not just contain it), then Text property must remain as the user inserted it. Here's the code of my derived class
public class customTB : ComboBox
{
private object[] startlist;
public customTB() : base()
{
this.AutoCompleteMode = System.Windows.Forms.AutoCompleteMode.None;
this.AutoCompleteSource = System.Windows.Forms.AutoCompleteSource.None;
this.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDown;
this.Sorted = true;
this.KeyPress += customTB_KeyPress;
this.TextChanged += customTB_TextChanged;
this.Enter += customTB_Enter;
}
void customTB_Enter(object sender, EventArgs e)
{
this.DroppedDown = (this.Items.Count > 0);
}
void customTB_TextChanged(object sender, EventArgs e)
{
UpdateList();
}
void customTB_KeyPress(object sender, KeyPressEventArgs e)
{
this.DroppedDown = (this.Items.Count>0);
}
void UpdateList()
{
if (this.startlist == null)
{
//get starting lists elems
this.startlist = new Object[this.Items.Count];
this.Items.CopyTo(this.startlist, 0);
}
this.BeginUpdate();
foreach (object o in startlist)
{
if (o.ToString().Contains(this.Text))
{
if (!this.Items.Contains(o))
this.Items.Add(o);
}
else if (this.Items.Contains(o))
this.Items.Remove(o);
}
this.EndUpdate();
}
}
If tried, any time you try to exit the ComboBox, Text is highlighted and its value is set to an item.
As example of what i would like to have is:
items contains "Doe John", "Smith John", "Smith Marie".
if user types "John", then dropdown items are "Doe John" and "Smith John" but if he doesn't click any of the dropdown elements and exit the ComboBox (i.e. clicking outside), the Text remains "John"
Have one boolean variable itemClicked
Set itemClicked to false inside Enter event handler
Set itemClicked to true inside SelectionChangeCommitted event handler
Set Text property to string.Empty if not itemClicked inside DropDownClosed event handler
I'm trying to retrieve the value of a DataGridViewComboBoxCell in the following way
When adding items to the ComboBox:
public void LoadLayouts()
{
ImmutableSet<string> layoutNames = _store.Current.Keys;
var dgvComboBox = (DataGridViewComboBoxColumn)this.schedulesDataGrid.Columns[1];
foreach (string name in layoutNames)
{
dgvComboBox.Items.Add(name);
}
}
When trying to read back the value:
var combo = (DataGridViewComboBoxCell) this.schedulesDataGrid[args.ColumnIndex, args.RowIndex];
string LayoutChosen = (string)combo.Value;
However, even if I can see that there is a value selected in the ComboBox, the Value comes back as null, and the FormattedValue comes back as "".
I've tried just setting the array of names as my DataSource, but then I'm not sure what to set for my Display and Value Members, considering I only have a single value (the name of the layout)
Thoughts?
At the time you attempt to read the cell's value, the row has not committed changes. If you have row headers visible, you will see the pencil icon on the row that has not been committed. This normally happens after the cell looses focus. You can force the issue by hooking into the in-place editing control combo-box and causing it to post EndEdit when it changes values:
void dgv_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
{
var comboBox = e.Control as ComboBox;
if (comboBox != null)
{
// remove any handler we may have added previously
comboBox.SelectionChangeCommitted -= new EventHandler(comboBox_SelectionChangeCommitted);
// add handler
comboBox.SelectionChangeCommitted += new EventHandler(comboBox_SelectionChangeCommitted);
}
}
void comboBox_SelectionChangeCommitted(object sender, EventArgs e)
{
// Allow current dispatch to complete (combo-box submitting its value)
// then EndEdit to commit the change to the row
dgv.BeginInvoke(new Action(() => dgv.EndEdit()));
}
I am calling the following on ToolStripMenu item click :
protected void windowNewMenu_Click(object sender, EventArgs e)
{
if (_selectedThings.Contains(((ToolStripMenuItem)sender).Tag))
{
selectedItemsPropertyGrid.SelectedObject = ((ToolStripMenuItem)sender).Tag;
selectedItemsComboBox.SelectedText = (((ToolStripMenuItem)sender).Tag.GetType()).ToString();
}
}
However the second line that is supposed to change does not seem to produce any visible changes to the ComboBox. Any Suggestions?
SelectedText is for highlighting a portion of the text, not selecting an item in the list. For that, you need SelectedItem.
Or you can just use:
selectedItemsComboBox.Text = ...
I've a very trivial requirement which makes me go nuts. I've a DataGridView in windows forms application. This contains one databound ComboBox Column. I'm using DisplayMember and ValueMember properties of that combobox.
Now my requirement is ComboBox should show the list of DisplayMembers in drop down list but when user selects one item from it, I should display the part of that DisplayMember in the combobox cell visible to the user. For example.
My display member list looks as below:
"Cust1 - Customer 1"
"Cust2 - Customer 2"
"Cust3 - Customer 3"
and when user selects any one of them from the above list (Say user selected 'Cust2 - Customer 2') then I need to display the value in the combobox column cell as only "Cust2" instead of complete DisplayMember text.
This DisplayMember list is a combination of two fields from the datasource bound to it i.e. First part points to CustomerCode field and second part points Customer name. I need to display only CustomerCode in the ComboBox cell after user selects one item from the drop down list.
How can I do this? Or should I come up with my own control which will have a different AutoCompleteCustomSource and display member value. Even I'm confused with that approach too.
Update: As no one has come up with any solution to my problem. Now I'm starting a bounty for that, also if anyone can suggest me other way to implement the same functionality, it would be great.
I've even tried to come up with my own control and tried to work on simple combobox to display a different value than the selected dropdown list, even that didn't work. Is there any other way to implement this? Any tips and tricks are greatly appreciable.
#Anurag: Here is the code which I've used.
Created a datagridview in the design mode. Created one column of type 'DataGridViewComboBoxColumn' that and named it as CustomerColumn.
In the designer file it looks like below:
private System.Windows.Forms.DataGridViewComboBoxColumn CustomerColumn;
This is the entity class which I've used for datasource
public class Customer
{
public int Id { get; set; }
public string CustCode { get; set; }
public string CustName { get; set; }
public string NameWithCode { get; set; }// CustCode - CustName format
}
In the form load event I'm doing the following:
CustomerColumn.DataSource = GetCustomers();
CustomerColumn.DisplayMember = "NameWithCode";
CustomerColumn.ValueMember = "Id";
I'm answering my own question because I've implemented my own solution to this by using custom control.
This custom control is created by keeping a textbox above combo box in such a way that only drop down button of combobox is visible.
Now I've created a custom column in datagridview deriving the DataGridViewEditingControl from my usercontrol.
I've added a property in Usercontrol which will take drop down list source from the control which is hosting datagridview.
Now in the EditingControlShowing event I'm setting this property as below
private void dataGridView2_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
{
if(dataGridView2.CurrentCell.ColumnIndex.Equals(0) && e.Control is UserControl1)
{
var uscontrol = e.Control as UserControl1;
uscontrol.DropDownListSource = source;
}
}
This drop down list source is used in the usercontrol to set the autocompletesource to the textbox and datasource to the combobox as below:
Whenever I set the DropDownDataSource I'm firing an event in the usercontrol which will do the following. This is to ensure that every time EditingControlShowing event occurs for this column in DataGridView, this source is updated for textbox and combobox in usercontrol.
private void DropDownSourceChanged(object sender, EventArgs eventArgs)
{
textBox1.AutoCompleteCustomSource = DropDownListSource;
textBox1.AutoCompleteMode = AutoCompleteMode.SuggestAppend;
textBox1.AutoCompleteSource = AutoCompleteSource.CustomSource;
comboBox1.DataSource = DropDownListSource;
}
Now whenever user starts typing in the textbox autocomplete source will display dropdown list with 'NameWithCode' values and if user selects one of them then I'll set it to the Text propery overidden in my usercontrol which will be used for the cell value in the DataGridView. Now based on the Textbox text (which is NameWithCode) I can get the code part and set it to the text property.
If user uses combobox dropdown button to select the item then I'll get the combobox selected text and set it in the Textbox which is ultimately used by the cell for getting value.
This way I could achieve the solution I want.
#Homam, solution also works but when I change the ComboBox's DropDownStyle to allow the user to type the value in the combobox it behaves weirdly and not getting up to the mark solution for my requirement. Hence I used this solution.
I know that this is not perfect solution, but I looked for a better one and I didn't find, so I went to a workaround
I did the following:
when the user open the ComboBox, I change the DisplayMember to "NameWithCode"
when the user close it, I return it to "CustCode"
You can Access to the ComboBox control by DataGridView.EditingControlShowing event for the DataGridView.
The code:
private void dataGridView1_EditingControlShowing(object sender,
DataGridViewEditingControlShowingEventArgs e)
{
var comboBox = e.Control as ComboBox;
comboBox.DropDown += (s1, e1) => comboBox.DisplayMember = "NameWithCode";
comboBox.DropDownClosed += (s2, e2) =>
{
// save the last selected item to return it after
// reassign the Display Member
var selectedItem = comboBox.SelectedItem;
comboBox.DisplayMember = "CustCode";
comboBox.SelectedItem = selectedItem;
};
}
Note: You have to start the DisplayMember with "CustCode"
Good luck!
Each time at the offensive of event dataGridView1_EditingControlShowing there is addition of new handlers for events comboBox.DropDown and comboBox.DropDownClosed. It results in the increase of number of these handlers and their repeated calls. This code decides this problem.
private void dataGridView1_EditingControlShowing(object sender,
DataGridViewEditingControlShowingEventArgs e)
{
var comboBox = e.Control as ComboBox;
comboBox.DropDown += comboBox_DropDown;
comboBox.DropDownClosed += comboBox_DropDownClosed;
}
private void comboBox_DropDown(object sender, System.EventArgs e)
{
var comboBox = sender as ComboBox;
if(comboBox != null)
{
comboBox.DropDown -= comboBox_DropDown;
comboBox.DisplayMember = "NameWithCode";
}
}
private void comboBox_DropDownClosed(object sender, System.EventArgs e)
{
var comboBox = sender as ComboBox;
if(comboBox != null)
{
comboBox.DropDownClosed -= comboBox_DropDownClosed;
var selectedItem = comboBox.SelectedItem;
comboBox.DisplayMember = "CustCode";
comboBox.SelectedItem = selectedItem;
}
}