Develop Reference

Combobox with Textbox content issue

I am running into an issue when using a textbox as the content of a combobox in WPF. When I have some items in the combobox already and then enter an extension of one of those items in the textbox, the textbox clears itself when it matches one of the existing items. An example:
The combobox contains the following:
'test1'
'test2'
I then attempt to enter the value 'test23'. When I get to 'test2' the matching value in the combobox is highlighted. When I proceed to type the '3' in 'test23', the textbox is cleared and all I am left with is a '3'. Obviously this is not a desired behavior.
I've looked through the configurable properties on microsoft's documentation pages and I haven't been able to find a property or combination that allows me to disable this behavior. Does anyone know what's going on here as well how I might fix it? Thanks.

If your are trying to add extension text to your default text in combobox items, try in code behind to declare the text items as a stringbuilder and use the property Append as follow
Code behind:
System.Text.StringBuilder text = new System.Text.StringBuilder();
TextBox textitem = new TextBox();
text="set the default text you want";
textitem.text=text;
Combobox.items.add(textitem);
text.append("the extension text you want");
Hope it helps.

uable to retrieve radio button value from database

I have a method called void showdata() and If I do this...
textBox1.Text = ds.Tables[0].Rows[rno][0].ToString();
comboBox1.Text = ds.Tables[0].Rows[rno][1].ToString();
I am able to retrieve values from database but I am unable to retrieve value from radiobuttons e.g.
rBMale.Text = ds.Tables[0].Rows[rno][3].ToString();
by using navigation buttons.
When I say values I mean the green dot that you see from the application not the string value. I have named rBMale as radiobutton.
Does anyone know why that is?
Thanks

It is not clear, but it seems that you want to set the Checked property of the RadioButton.
rBMale.Checked = Convert.ToBoolean(ds.Tables[0].Rows[rno][3]);
This property is used to paint the RadioButton with the glyph to represent the value for true or for false

The Text property of radio buttons and check boxes is the on screen text that tells the user what the button is (in theory) and has little or nothing to do with its value. What you are probably looking for is the Checked property, which is a bool.
try something along these lines:
rBMale.Checked = Convert.ToBoolean(ds.Tables[0].Rows[rno][3]);

C# Datagridview: get selected item in combobox columns

I'm working on a GUI that allows the user to manipulate xml files. I display the xml file in a datagridview organized neatly by columns through xml elements. I allow the user to add columns as an extention on my project. The column gets added to the dataset table, then updated to the datagridveiew that I use to display the xml file in. I've included the ability for the user to add a combobox column to select choices instead of entering them in constantly like.. true or false. However, that is where the problem lies. Saving a normal column was easy. The combobox column is being a pain.
I have a "save combobox column" to have it updated to the xml and a "save" button to save in a destination of the user's choice.
I've done some research and it seems like the combobox class has such a feature to gain access to the selecteditem in the combobox put in by the user.
Where we have:
ComboBox box = new ComboBox();
box.SelectedItem;
I tried applying this to the combobox column class but it does not have such a function. Thus, I cannot figure out how to directly obtain the value of the user's selected item. I tried experimenting with comboboxcell's as well, but that didn't lead me anywhere either. Both those classes I played around with do not have a... "selected item" function and even google does not have a solution for me. =( I've also tried using the cell.value, but it is "null" for some reason. Even when the user selects an item in the box, it doesn't get saved into the cell's value.
TLDR:
My question in short is, how, if possible, do you gain access to the comboboxcolumn cell's selected item? Additionally, how would you then ensure that the item value is saved in the cell?
Thanks in advance. I'm using .NET 3.5 SP1, through Visual Studio 2008 C#.
Sincerely,
tf.rz

The Control in a DataGridView is not a ComboBox, it is a DataGridViewComboBox and has different properties and methods. From MSDN
Unlike the ComboBox control, the DataGridViewComboBoxCell does not have SelectedIndex and SelectedValue properties. Instead, selecting a value from a drop-down list sets the cell Value property.
However, you mentioned that the Cell.Value is null for you. Well there may be another step you are missing according to the following article (How to: Access Objects in a Windows Forms DataGridViewComboBoxCell Drop-Down List).
You must set the DataGridViewComboBoxColumn.ValueMember or DataGridViewComboBoxCell.ValueMember property to the name of a property on your business object. When the user makes a selection, the indicated property of the business object sets the cell Value property.

If we have bound a datagridcomboboxcell with a different DisplayMember and ValueMember, like so:
dgcombocell.DisplayMember = "Name";
dgcombocell.ValueMember = "Id";
dgcombocell.DataSource = dataset1.Tables[0];
Then for getting SelectedText, and SelectedValue, we can write this code:
string SelectedText = Convert.ToString((DataGridView1.Rows[0].Cells["dgcombocell"] as DataGridViewComboBoxCell).FormattedValue.ToString());
int SelectedVal = Convert.ToInt32(DataGridView1.Rows[0].Cells["dgcombocell"].Value);
I hope it solves your problem.

Use this to get or set selected value:
object selectedValue = currentRow.Cells["comboboxColumnName"].Value
Don't forget to set DisplayMember and ValueMember for your DataGridViewComboBoxColumn

This is how it is done
DataGridViewComboBoxCell comboCell = (DataGridViewComboBoxCell)dgv.Rows[0].Cells[1];
MessageBox.Show(""+comboCell.Items.IndexOf(comboCell.Value));

A .Net combox is actually a composite control made up of a textbox and a dropdownlist. Use box.Text to get the currently displayed information.
EDIT: The row or the cell should have a .FindControl() method. You'll need to do something like:
Combobox box = (Combobox)(row.FindControl("[combobox ID]"));
string val = box.Text;
Basically, you're finding the control within its container (row or cell), then casting the control found as a combobox, then accessing its .Text property.

I use this:
private int GetDataGridViewComboBoxCellSelectedIndex(DataGridViewCell d)
{
return ((DataGridViewComboBoxCell)d).Items.IndexOf(d.Value);
}

Data-binding taking too long to update

In my application I have this code in my view model:
hiddenTextContainer.PreHideVerticalOffset = VerticalOffset;
hiddenTextContainer.HiddenText = Text.Remove(SelectionStart, SelectionLength);
hiddenTextContainer.HasHiddenText = true;
hiddenTextContainer.NonHiddenTextStart = SelectionStart;
Text = Text.Substring(SelectionStart, SelectionLength);
SelectionStart = Text.Length;
hiddenTextContainer.ImmediatePostHideVerticalOffset = VerticalOffset;
This code is used to hide selected text in a textbox. Text is a string property data bound to the text property of a textbox and VerticalOffset is a double property data bound to the VerticalOffset property of that same textbox.
I need to save the VerticalOffset before and after the hiding of selected text takes place, but with my code below both hiddenTextContainer.PreHideVerticalOffset and hiddenTextContainer.ImmediatePostHideVerticalOffset are always set to the same value no matter what.
I have figured out that this is because the text of the textbox has not been updated by the time the code reaches:
hiddenTextContainer.ImmediatePostHideVerticalOffset = VerticalOffset;
Is there any way I can fix this?

It is probably not that the property of text is being updated too slowly, it's that the Measure and Arrange is being performed asynchronously. I'd suggest explicitly calling Window.UpdateLayout (or similar, depending on the container you need to recalculate).
Possibly, you'll need to do, InvalidateArrange or InvalidateMeasure first.

Combobox population problem

So I have a combobox - the designer code:
this.cmbStatusBox.Items.AddRange(new object[] {
"Ordered",
"Cooking",
"In-transit",
"Delivered"});
The formload code:
if (mainForm.boolEdit == true)
{
this.cmbStatusBox.Items.AddRange(new object[] {
"Cooking",
"In-transit",
"Delivered"});
}
else
{
this.cmbStatusBox.Items.AddRange(new object[] {
"Ordered"});
}
As you can see, I am trying to make the combobox have different values.
As things stand, i get both whats in the designer and in formload in the comboboxes.
How can i stop this?
I also have an edit function, so when i edit a record, i want the combo box to be populated by what is already saved.
Just a random question, can you stop the user entering a value that isn't in the combo box?
Thankyou

If you want to replace the current contents then you'll need to call
this.cmbStatusBox.Items.Clear();
before adding your new values.
ComboBox MSDN page
ComboBox.Items MSDN page
The DropDownStyle property also specifies whether the text portion can be edited.
Source
The values are:
Simple Specifies that the list is always visible and that the text portion is editable. This means that the user can enter a new value and is not limited to selecting an existing value in the list.
DropDown Specifies that the list is displayed by clicking the down arrow and that the text portion is editable. This means that the user can enter a new value and is not limited to selecting an existing value in the list. When using this setting, the Append value of AutoCompleteMode works the same as the SuggestAppend value. This is the default style.
DropDownList Specifies that the list is displayed by clicking the down arrow and that the text portion is not editable. This means that the user cannot enter a new value. Only values already in the list can be selected. The list displays only if AutoCompleteMode is Suggest or SuggestAppend.
Source

Just remove the items from the designer code.