I am trying to get required data into controls when i select specific Student Name from a combobox. i am using SelectedValueChanged event for this and the valuemember for that combobox in order to populate it with required data.
StudentsNamesComboBox.DisplayMember = "StudentName";
StudentsNamesComboBox.ValueMember = "SectionId";
here the studentnameCombobox has a different value from the parameter value required to get specific record from database using storedprocedure.
cmd.Parameters.AddWithValue("#AdmissionNumber", Convert.ToInt16(StudentsNamesComboBox.SelectedValue));
the problem i am facing is that i can't get the required parameter value (#AdmissionNumber) from the selected name in the studentNamesCombox.
any idea how to get the required parameter value without changing the studentNamesCombox valuemember? any other way around? because changing vlauemember will affect the whole functionality.
Regards
When you are populating StudentName combobox, why don't you set the ValueMember of that combobox to "AdmissionNumber".
You do not need SectionI of the student in that combobox. SectionId is already available in the other combobox. In StudentName combobox all the items have same sectionId. Correct me if my assumption is wrong.
This way ComboBox.SelectedValue will give the value associated with the selected item which in your case will be "AdmissionNumber".
To get the name of the selected student you need to use ComboBox.SelectedItem.Text. That will give the Selected StudentName in your case.
Related
Here's what I have so far:
I have a ComboBox that I'm filling via pulling some playlists from a C# Spotify API.
I get the values - playlist.Id and playlist.Name from a playlist object.
Each playlist populates its Id and Name into a row in my ComboBox dropdown so the user can see a list of their personal playlists.
Next, the user chooses their selected playlist in the ComboBox and can pull a ListView of all the tracks (artists etc).
This step requires selecting the user's ComboBox selection but I can only use the playlist.Id value. However, I need to include the playlist.Name in the box so the user knows what playlist to select.
Obviously, this is pulling the name AND Id from the selected ComboBox option and I can't use these two values for the tracklist pull. I only want the Id string.
Is there any way to select only part of the ComboBox string (just the ID) or assign a value and a text separately to one row in my ComboBox?
Appreciate I'm probably doing this a silly way.
I've also tried:
Creating a separate array with just the playlist Id's and trying to use the selected index of ComboBox to match with the array index (only containing the id and not the name).
userPlaylists.Items.ForEach(playlist =>
{
playlistArray[i] = playlist.Id;
comboPlaylists.Items.Add(playlist.Name + playlist.Id);
i++;
});
There are ways to extract part of the ComboBox text but this isn't the right way. Instead, you should use Data Binding. Set the DataSource, DisplayMember, and ValueMember properties of the ComboBox so that you can later access the SelectedValue which would be the ID.
Here's an example:
comboPlaylists.DisplayMember = "Name";
comboPlaylists.ValueMember = "Id";
// I'm assuming that `userPlaylists.Items` is a generic list.
// Otherwise, you might want to use `userPlaylists.Items.ToList()` instead.
comboPlaylists.DataSource = userPlaylists.Items;
Now, when you want to get the Id of the selected PlayList, you can use something like this:
var id = (int)comboPlaylists.SelectedValue; // Assuming the ID is an integer.
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);
}
I am working on a project for my college where I need to bind data from database into the combobox. I need to store the roll no / enrollment no in the "value" field of combobox and name of the student in the "text" property of the combobox. How can I do that?>???
Please reply ASAP....
You will need to set the DataSource of the combobox to your datasource. Then the ValueMember for the Roll No and the DisplayMember for the name of the student.
e.g
cboStudents.DataSource = dataSet1.Tables["Students"];
cboStudents.ValueMember = "RollNumber";
cboStudents.DisplayMember = "StudentName";
The two complex-bound controls you've most likely encountered are the ComboBox and the Listbox. To complex-bind one of these controls, you need to set the DataSource (where values originate), the DisplayMember (the name of the column of data that supplies the visible list items), and the ValueMember (the name of the column of data that supplies the possible control values).
combobox.DataSource = dataTable
combobox.ValueMember = "id"
combobox.DisplayMember = "name"
I have a comboBox that displays different Municipalities (these Municipalities belongs to a particular Province) in our country. Since there are Municipalities having the same name, I binded the "MunicipalityName" (a table column from 'MUNICIPALITY' table in my database) to DisplayMember property of the comboBox and "Municipality_ID" to ValueMember property of the comboBox.
When the user saves his details, I supply the SelectedValue from ValueMember of the MUNICIPALITY and insert it to Employee table.
cmd.Parameters.Add(new SqlParameter("#Municipality_ID", (object)comboBoxMunicipality.SelectedValue.ToString()));
I find it hard when it comes to retrieval of data when an Employee needs to update his information. I have to manually check the Municipality_ID of that employee and compare it to the binded data in the comboBox, then loop through it, determine what index that Municipality_ID located, and set the SelectedIndex property of the comboBox. (Quiet lengthy compared to code snippet below)
I have this code, but I find conflicts since Municipality_Name is not unique.
//set SelectedIndex based from DisplayMember of the comboBox
comboBoxMunicipality.SelectedIndex = comboBoxMunicipality.FindStringExact(dataTable.Rows[0]["MunicipalityName"].ToString());
Is there a way to set the SelectedIndex of the comboBox like the code above, but this time, comparing it to the ValueMember?
Is there a shortcut?
//something like this?
comboBoxMunicipality.SelectedIndex =
comboBoxMunicipality.FindByValue(dataTable.Rows[0]["Municipality_ID"].ToString());
I hope you get my point guys... Please help. Thanks.
How about this?
comboBoxMunicipality.SelectedValue = theMunicipalityIDtoSelect
Edit 1
I believe my problem stems from the following. The function that fills the dropdown portion sets the Display Member to the CountyName. Then when I try and set the SelectedText or EditValue, as has been suggested, that function only returns the CountyID which it try's to match to something in the DropDown list DisplayMember. I need it to match it to something in the ValueMember list.
Using the following I got it to work but it is a HACK and I'd greatly appreciate finding a real solution.
lkuResidenceCounty.ItemIndex = Convert.ToInt32(row["ResidencyCountyID"].ToString());
Original Post
I have a lookup box(DevExpress) on a member form that I fill the possible values in from the DB with this code -->
lkuResidenceCounty.Properties.DataSource = ConnectBLL.BLL.Person.CountyList();
lkuResidenceCounty.Properties.PopulateColumns();
lkuResidenceCounty.Properties.DisplayMember = "CountyName";
lkuResidenceCounty.Properties.ValueMember = "CountyID";
lkuResidenceCounty.Properties.Columns[0].Visible = false;
lkuResidenceCounty.Properties.Columns[2].Visible = false;
lkuResidenceCounty.Properties.Columns[3].Visible = false;
This works just fine as the CountyName is displayed as expected.
However, When I try and load an existing member's value for this field using the below, which is part of a function that takes a row from the DataSet -->
lkuResidenceCounty.Properties.ValueMember = row["ResidencyCountyID"].ToString();
I get a blank box. I have stepped through the code and the correct ID is being returned for the member.
Unfortunately the stored procedure to fill the dropdown options pulls from a Maintenance Table with the columns "CountyName" & "CountyID". So that is correct. Unfortunately, the stored procedure to load a specific person's current county pulls from the Person Table where there is a column called "ResidencyCountyID". It is so named because there is also a "ResponsibilityCountyID" column.
I need a way for them both to coexist, any solutions?
Thanks!
DisplayMember and ValueMember are used to populate the control with the list of selectable values. To set the selected value of a populated LookUpEdit control, set its EditValue property:
lkuResidenceCounty.EditValue = row["ResidencyCountyID"].ToString();
In response to your edit: According to the documentation:
The currently selected row determines values for the editor's edit value and display text. The value for BaseEdit.EditValue is obtained from the RepositoryItemLookUpEditBase.ValueMember field, while the text to display in the edit box is obtained from the RepositoryItemLookUpEditBase.DisplayMember field of the selected row.
When you change BaseEdit.EditValue,
the editor locates and selects the row
whose
RepositoryItemLookUpEditBase.ValueMember
field contains the new value. The text
in the edit box is changed to reflect
the newly selected row.
I don't use these controls but it sounds to me that it shouldn't be working as you described. I think the ToString() is the problem because EditValue accepts an object so it's probably expecting an int for the value. Try:
lkuResidenceCounty.EditValue = (int)row["ResidencyCountyID"];
The ValueMember property tells the list what field to pull from when setting the Value property. Once you've set the ValueMember to "CountyID", then when the list is Databound, it will set all the list items' value properties to their respect objects' CountyID fields.
Hence, you should not do:
lkuResidenceCounty.Properties.ValueMember = row["ResidencyCountyID"].ToString();
but rather
lkuResidenceCounty.Properties.ValueMember = "CountyID";
was perfectly fine, as long as you've correctly identified the field you're trying to databind. Once the list get's databound you should see the results you're expecting.
However, after looking at your code, it seems that you're mismatching your field. In one place you're using ResidencyCountyID and in another you're using CountyID. That is most likely your source of confusion. Figure out what the actual field name is and make sure you set the ValueMember to that.
UPDATE
After reading your comment, what your looking for is the SelectedValue property. The SelectedValue property tells the list to force the selected value to whatever input you give it.
Essentially you have two things going on here. ValueMember tells the list what to use as the value from your data source, and SelectedValue which tells the list what the currently selected value should be.
Why is it that you need the same LookUpEdit to have two value members? Is it being used standalone or in a grid? If standalone, you could swap out the two repository editors depending on the current row. But, are there more than 2 possible values for the ValueMember? That would also complicate things.
UPDATE
Looking at your edit, I think I understand what's going on a little more. So, you don't wish to change your ValueMember (which refers to a data column), but rather to change the value of the editor? If so, then you should definitely use EditValue (not SelectedText, which I don't believe is meant to be set), and assign it to row["value_field"] like so:
lkuResidenceCounty.EditValue = row["ResidencyCountyID"];
What happens when you do that?