I have a list of objects that I'm adding to.
private List<Employee> employees = new List<Employee>();
I have a button on my form application to create a new employee object and add it to the list. Prior to clicking it, it displays "Add Hourly Employee". After clicking it, it changes to "Save Hourly Employee". I'm just using a boolean to determine what text to display.
private void addHrlyEmpBtn_Click(object sender, EventArgs e)
{
resetBtn.Enabled = true;
cancelBtn.Enabled = true;
if (!addHourly)
{
resetBtn.Enabled = true;
cancelBtn.Enabled = true;
textBox4.Enabled = false;
textBox4.Text = (employees.Count + 1).ToString();
textBox7.Enabled = false;
addHrlyEmpBtn.Text = "Save Hourly Employee";
}
else if (addHourly)
{
//Grab values, create new object, and add to list.
//Set addHourly to false;
}
//Other stuff
}
I'm trying to display employees.Count + 1 to textBox4, but for some reason it isn't working. No text is being displayed at all. Idealy, I'd like to have the text box disabled but still display the value. And I only want it to display when !addHourly.
Am I doing something wrong?
There's nothing wrong in principal with the code you wrote.
I would strongly suggest giving meaningful names to all of your variables. Names like textBox4 are likely to cause confusion for yourself and future maintainers of the code.
If the value is not changing as you expect, you are most likely not entering that if branch.
Set a breakpoint at
if (!addHourly)
See if addHourly has the value you expect.
Check if addHrlyEmpBtn_Click is being called at all.
if it isn't try associating the Click event with addHrlyEmpBtn_Click method from the designer
or add addHrlyEmpBtn.Click += addHrlyEmpBtn_Click; in the constructor
Related
Once again I am in need of your assistance. I have two combobox's one called cmbRFR and one called cmbSubRFR. The items in the cmbRFR are:
Null
POSITIONING
ARTEFACT
PATIENT ID
EXPOSURE ERROR
TEST IMAGES
I need to set it up so that when the user selects one of the items in cmbRFR, it changes the items displayed in cmbSubRFR. cmbSubRFR should work as follows.
When user selects Null, the combobox should also display Null/a blank item.
When user selects POSITIONING:
Anatomy cut-off
Rotation
Obstructed view
Tube or grid centering
Motion
When user selects ARTEFACT the combobox should also display ARTEFACT.
When user select PATIENT ID:
Incorrect Patient
Incorrect Study/Side
User Defined Error
When user select EXPOSURE ERROR:
Under Exposure
Over Exposure
Exposure Malfunction
When user selects TEST IMAGES:
Quality Control
Service/Test
I have no code to provide for this one as I have no idea how to go about doing this. I have looked around at some other questions that are similar to this however I have found nothing that might help me.
Any suggestions would be helpful.
public partial class Form1 : Form
{
string cmbRFR_item;
public Form1()
{
InitializeComponent();
}
private void change_cmbSubRFR_items()
{
cmbSubRFR.Items.Clear();//Clear all items in cmbSubRFR comboBox.
switch (cmbRFR_item)//Adding your new items to cmbSubRFR.
{
case "Null":
cmbSubRFR.Items.Add("Null/a blank item");
cmbSubRFR.Text = "Null/a blank item";
break;
case "POSITIONING":
cmbSubRFR.Items.Add("Anatomy cut-off");
cmbSubRFR.Items.Add("Rotation");
cmbSubRFR.Items.Add("Obstructed view");
cmbSubRFR.Items.Add("Tube or grid centering");
cmbSubRFR.Items.Add("Motion");
cmbSubRFR.Text = "";
break;
case "ARTEFACT":
cmbSubRFR.Items.Add("ARTEFACT");
cmbSubRFR.Text = "ARTEFACT";
break;
case "PATIENT ID":
cmbSubRFR.Items.Add("Incorrect Patient");
cmbSubRFR.Items.Add("Incorrect Study/Side");
cmbSubRFR.Items.Add("User Defined Error");
cmbSubRFR.Text = "";
break;
case "EXPOSURE ERROR":
cmbSubRFR.Items.Add("Under Exposure");
cmbSubRFR.Items.Add("Over Exposure");
cmbSubRFR.Items.Add("Exposure Malfunction");
cmbSubRFR.Text = "";
break;
case "TEST IMAGES":
cmbSubRFR.Items.Add("Quality Control");
cmbSubRFR.Items.Add("Service/Test");
cmbSubRFR.Text = "";
break;
}
}
private void cmbRFR_SelectedIndexChanged(object sender, EventArgs e)
{
if (cmbRFR_item!= cmbRFR.SelectedItem.ToString())//This will control your changes in cmbRFR about selected item and call change_cmbSubRFR_items()
{
cmbRFR_item = cmbRFR.SelectedItem.ToString();
change_cmbSubRFR_items();
}
}
}
There are two ways to go about solving this. First the "correct way", which is to set the DataSource property. Create lists for each combobox, like this:
var _positioningItems = new List<string> { "Anatomy cut-off", "Rotation", "Obstructed view" };
var _patientIdItems = new List<string> { "Incorrect Patient", "Incorrect Study/Side", "User Defined Error" };
Then subscribe to the OnSelectedIndexChange event on the cmbRFR combobox and then in the event handler, set the DataSource to the appropriate list.
The other way to do it, which I'm not in favor of, is to create comboboxes for each cmbRFR item, then hide them all and only show the appropriate one to the user. Subscribe to the OnSelectedIndexChange event on the cmbRFR combobox and hide/show the appropriate combobox.
When the DataGridView in my application is populated, the following method is fired:
public void OrderSelectionChanged()
{
ConfirmOrCancelChangesDialog();
// Get values from selected order and populate controls
if (view.OrderTable.SelectedRows.Count != 0)
{
OrderViewObject ovm = (OrderViewObject)view.OrderTable.SelectedRows[0].DataBoundItem;
selectedOrder = orderModel.GetOrderById(ovm.OrderId);
// Populate view controls with data from selected order
view.OrderID = selectedOrder.Id.ToString();
---->> view.OrderDateCreated = selectedOrder.DateCreated; <<-----
view.OrderDeliveryDate = selectedOrder.DeliveryDate;
PopulateOrderAddressControls(selectedOrder.Address);
PopulateOrderItemTableControl();
PopulateOrderWeightAndSumControls();
view.OrderNote = selectedOrder.Note;
// Enable buttons
view.DeleteOrderButtonEnabled = true;
view.NewOrderItemButtonEnabled = true;
}
else
{
view.DeleteOrderButtonEnabled = false;
}
}
For some reason, the "isSaved" variable is being changed from true to false at the row I marked with arrows and I can't figure out why. This is not supposed to happen and was never an issue before, but suddenly appeared.
The variable "isSaved" is being checked in the following method:
public void ConfirmOrCancelChangesDialog()
{
if (!isSaved)
{
DialogResult dialog = MessageBox.Show(Properties.Resources.SaveChanges,
Properties.Resources.SaveChangesTitle, MessageBoxButtons.YesNo);
if (dialog == DialogResult.Yes)
{
SaveOrder();
}
else
{
UndoChanges();
}
}
}
This is causing the save or cancel dialog to appear everytime the application is started, which obviously is wrong. Since the selection changed method is fired three times and isSaved is changed during the first run, the dialog pops up during the second time around. Through debugging step by step I could figure out at what point isSaved is changing, but not how or why.
View is the form, OrderDateCreated is a getter/setter for a DateTimePicker, selectedOrder is just an order object and DateCreated a Date. Am I missing something here?
Cheers!
It seem related to your code setting values to view object.
If you didn't create properties by your own, that object may have set properties which detects any change and setting the isSaved properties to false.
Try this workaround:
bool wasSaved = isSaved; //reference properly to your isSaved variable, and store it in the wasSaved local var
view.OrderID = selectedOrder.Id.ToString();
view.OrderDateCreated = selectedOrder.DateCreated;
view.OrderDeliveryDate = selectedOrder.DeliveryDate;
isSaved = wasSaved; //revert to the previous state
I have a BindingList< KeyValuePair < string, string > > that is bound to a ComboBox control. Based on some conditions, the BindingList will be added a new KeyValuePair. Now, the Newly added item shows up at index 0 of the Combobox, instead of at the end.
While debugging, I found that the BindingList has got the right order. (i.e, the new KeyValuePair is appended)
Also, I check the SelectedValue of the ComboBox in it's SelectedIndexChanged handler and it seems to be not of the ListItem that got selected. Instead, it is that of the supposed ListItem, if the ComboBox had got the right order as in its DataSource, - the BindingList..
The code is a small part of a large project.. Plz let me know if the question is not clear. I can put the relevant parts of the code as per our context.
How could something like this happen? What can I do differently?
I have this class something like this.
public class DropdownEntity
{
//removed all except one members and properties
private string frontEndName
public string FrontEndName
{
get {return this.frontEndName; }
set {this.frontEndName= value; }
}
//One Constructor
public DropdownEntity(string _frontEndName)
{
this.FrontEndName = _frontEndName;
//Removed code which initializes several members...
}
//All methods removed..
public override string ToString()
{
return frontEndName;
}
}
In my windows form, I have a tab control with several tabs. In one of the tabs pages, I have a DataGridView. The user is supposed to edit the cells and click on a Next - button. Then, some processing will be done, and the TabControl will be navigated to the next tab page.
The next tab page has the combobox that has the problem I mentioned. This page also has a back button, which will take back.. the user can modify the gridview cells again.. and click on the next button. This is when the order gets messed up.
I am posting here the Click event handler of the Next Button.. Along with the class, with the rest of the code removed.
public partial class AddUpdateWizard : Form
{
//Removed all members..
BindingList<KeyValuePair<string, string>> DropdownsCollection;
Dictionary<string, DropdownEntity> DropdownsDict;
//Defined in a partial definition of the class..
DataGridView SPInsertGridView = new DataGridView();
ComboBox DropdownsCmbBox = new ComboBox();
Button NextBtn2 = new Button();
Button BackBtn3 = new Button();
//Of course these controls are added to one of the panels
public AddUpdateWizard(MainForm mainForm)
{
InitializeComponent();
DropdownsDict = new Dictionary<string, DropdownEntity>();
}
private void NextBtn2_Click(object sender, EventArgs e)
{
string sqlArgName;
string frontEndName;
string fieldType;
for (int i = 0; i < SPInsertGridView.Rows.Count; i++)
{
sqlArgName = "";
frontEndName = "";
fieldType = "";
sqlArgName = SPInsertGridView.Rows[i].Cells["InsertArgName"].Value.ToString().Trim();
if (SPInsertGridView.Rows[i].Cells["InsertArgFrontEndName"].Value != null)
{
frontEndName = SPInsertGridView.Rows[i].Cells["InsertArgFrontEndName"].Value.ToString().Trim();
}
if (SPInsertGridView.Rows[i].Cells["InsertArgFieldType"].Value != null)
{
fieldType = SPInsertGridView.Rows[i].Cells["InsertArgFieldType"].Value.ToString().Trim();
}
//I could have used an enum here, but this is better.. for many reasons.
if (fieldType == "DROPDOWN")
{
if (!DropdownsDict.ContainsKey(sqlArgName))
DropdownsDict.Add(sqlArgName, new DropdownEntity(frontEndName));
else
DropdownsDict[sqlArgName].FrontEndName = frontEndName;
}
else
{
if (fieldType == "NONE")
nonFieldCount++;
if (DropdownsDict.ContainsKey(sqlArgName))
{
DropdownsDict.Remove(sqlArgName);
}
}
}
//DropdownsCollection is a BindingList<KeyValuePair<string, string>>.
//key in the BindingList KeyValuePair will be that of the dictionary.
//The value will be from the ToString() function of the object in the Dictionary.
DropdownsCollection = new BindingList<KeyValuePair<string,string>>(DropdownsDict.Select(kvp => new KeyValuePair<string, string>(kvp.Key, kvp.Value.ToString())).ToList());
DropdownsCmbBox.DataSource = DropdownsCollection;
DropdownsCmbBox.DisplayMember = "Value";
DropdownsCmbBox.ValueMember = "Key";
//Go to the next tab
hiddenVirtualTabs1.SelectedIndex++;
}
private void BackBtn3_Click(object sender, EventArgs e)
{
hiddenVirtualTabs1.SelectedIndex--;
}
//On Selected Index Changed of the mentioned Combobox..
private void DropdownsCmbBox_SelectedIndexChanged(object sender, EventArgs e)
{
if (DropdownsCmbBox.SelectedValue != null)
{
if (DropdownsDict.ContainsKey((DropdownsCmbBox.SelectedValue.ToString())))
{
var dropdownEntity = DropdownsDict[DropdownsCmbBox.SelectedValue.ToString()];
DropdownEntityGB.Text = "Populate Dropdowns - " + dropdownEntity.ToString();
//Rest of the code here..
//I see that the Datasource of this ComboBox has got the items in the right order.
// The Combobox's SelectedValue is not that of the selected item. Very Strange behavior!!
}
}
}
}
The very first time the user clicks the Next Button, it's fine. But if he clicks the Back Button again and changes the Data Grid View cells.. The order will be gone.
I know, it can be frustrating to look at. It's a huge thing to ask for help. Any help would be greatly appreciated!
Please let me know if you need elaboration at any part.
Thanks a lot :)
I think you have two problems here.
First, if you want to retain the order of the items you should use an OrderedDictionary instead of a regular one. A normal collection will not retain the order of the items when you use Remove method. You can see more info about this related to List here.
You could use such dictionary like this:
DropDownDict = new OrderedDictionary();
// Add method will work as expected (as you have it now)
// Below you have to cast it before using Select
DropDownCollection = new BindingList<KeyValuePair<string, string>>(DropDownDict.Cast<DictionaryEntry>().Select(kvp => new KeyValuePair<string, string>(kvp.Key.ToString(), kvp.Value.ToString())).ToList());
The second problem could be that you change the display name (FrontEndName) of already existing items, but the key is preserved. When you add a new item, try to remove the old one that you're not using anymore and add a new item.
The Sorted Property of the Combobox is set to True! I didn't check that until now. I messed up. Terribly sorry for wasting your time Adrian. Thanks a lot for putting up with my mess here.. :)
This is kind of a oddball problem so I will try to describe the best that I can.
I have a DataGridView that shows a list of contracts and various pieces of information about them. There are three view modes: Contract Approval, Pre-Production, and Production. Each mode has it's own set of columns that need to be displayed.
What I have been doing is I have three radio buttons one for each contract style. all of them fire their check changed on this function
private void rbContracts_CheckedChanged(object sender, EventArgs e)
{
dgvContracts.Columns.Clear();
if (((RadioButton)sender).Checked == true)
{
if (sender == rbPreProduction)
{
dgvContracts.Columns.AddRange(searchSettings.GetPreProductionColumns());
this.contractsBindingSource.DataMember = "Preproduction";
this.preproductionTableAdapter.Fill(this.searchDialogDataSet.Preproduction);
}
else if (sender == rbProduction)
{
dgvContracts.Columns.AddRange(searchSettings.GetProductionColumns());
this.contractsBindingSource.DataMember = "Production";
this.productionTableAdapter.Fill(this.searchDialogDataSet.Production);
}
else if (sender == rbContracts)
{
dgvContracts.Columns.AddRange(searchSettings.GetContractsColumns());
this.contractsBindingSource.DataMember = "Contracts";
this.contractsTableAdapter.Fill(this.searchDialogDataSet.Contracts);
}
}
}
Here is the GetxxxColumns function
public DataGridViewColumn[] GetPreProductionColumns()
{
this.dgvTxtPreAccount.Visible = DgvTxtPreAccountVisable;
this.dgvTxtPreImpromedAccNum.Visible = DgvTxtPreImpromedAccNumVisable;
this.dgvTxtPreCreateDate.Visible = DgvTxtPreCreateDateVisable;
this.dgvTxtPreCurrentSoftware.Visible = DgvTxtPreCurrentSoftwareVisable;
this.dgvTxtPreConversionRequired.Visible = DgvTxtPreConversionRequiredVisable;
this.dgvTxtPreConversionLevel.Visible = DgvTxtPreConversionLevelVisable;
this.dgvTxtPreProgrammer.Visible = DgvTxtPreProgrammerVisable;
this.dgvCbxPreEdge.Visible = DgvCbxPreEdgeVisable;
this.dgvCbxPreEducationRequired.Visible = DgvCbxPreEducationRequiredVisable;
this.dgvTxtPreTargetMonth.Visible = DgvTxtPreTargetMonthVisable;
this.dgvCbxPreEdgeDatesDate.Visible = DgvCbxPreEdgeDatesDateVisable;
this.dgvTxtPreStartDate.Visible = DgvTxtPreStartDateVisable;
this.dgvTxtPreUserName.Visible = DgvTxtPreUserNameVisable;
this.dgvCbxPreProductionId.Visible = DgvCbxPreProductionIdVisable;
return new System.Windows.Forms.DataGridViewColumn[] {
this.dgvTxtPreAccount,
this.dgvTxtPreImpromedAccNum,
this.dgvTxtPreCreateDate,
this.dgvTxtPreCurrentSoftware,
this.dgvTxtPreConversionRequired,
this.dgvTxtPreConversionLevel,
this.dgvTxtPreProgrammer,
this.dgvCbxPreEdge,
this.dgvCbxPreEducationRequired,
this.dgvTxtPreTargetMonth,
this.dgvCbxPreEdgeDatesDate,
this.dgvTxtPreStartDate,
this.dgvTxtPreUserName,
this.dgvCbxPreProductionId,
this.dgvTxtCmnHold,
this.dgvTxtCmnConcern,
this.dgvTxtCmnAccuracyStatus,
this.dgvTxtCmnEconomicStatus,
this.dgvTxtCmnSoftwareStatus,
this.dgvTxtCmnServiceStatus,
this.dgvTxtCmnHardwareStatus,
this.dgvTxtCmnAncillaryStatus,
this.dgvTxtCmnFlowStatus,
this.dgvTxtCmnImpromedAccountNum,
this.dgvTxtCmnOpportunityId};
}
public DataGridViewColumn[] GetProductionColumns()
{
this.dgvcTxtProAccount.Visible = DgvTxtProAccountVisable;
this.dgvTxtProImpromedAccNum.Visible = DgvTxtProImpromedAccNumVisable;
this.dgvTxtProCreateDate.Visible = DgvTxtProCreateDateVisable;
this.dgvTxtProConvRequired.Visible = DgvTxtProConvRequiredVisable;
this.dgvTxtProEdgeRequired.Visible = DgvTxtProEdgeRequiredVisable;
this.dgvTxtProStartDate.Visible = DgvTxtProStartDateVisable;
this.dgvTxtProHardwareRequired.Visible = DgvTxtProHardwareReqiredVisable;
this.dgvTxtProStandardDate.Visible = DgvTxtProStandardDateVisable;
this.dgvTxtProSystemScheduleDate.Visible = DgvTxtProSystemScheduleDateVisable;
this.dgvTxtProHwSystemCompleteDate.Visible = DgvTxtProHwSystemCompleteDateVisable;
this.dgvTxtProHardwareTechnician.Visible = DgvTxtProHardwareTechnicianVisable;
return new System.Windows.Forms.DataGridViewColumn[] {
this.dgvcTxtProAccount,
this.dgvTxtProImpromedAccNum,
this.dgvTxtProCreateDate,
this.dgvTxtProConvRequired,
this.dgvTxtProEdgeRequired,
this.dgvTxtProStartDate,
this.dgvTxtProHardwareRequired,
this.dgvTxtProStandardDate,
this.dgvTxtProSystemScheduleDate,
this.dgvTxtProHwSystemCompleteDate,
this.dgvTxtProHardwareTechnician,
this.dgvTxtCmnHold,
this.dgvTxtCmnConcern,
this.dgvTxtCmnAccuracyStatus,
this.dgvTxtCmnEconomicStatus,
this.dgvTxtCmnSoftwareStatus,
this.dgvTxtCmnServiceStatus,
this.dgvTxtCmnHardwareStatus,
this.dgvTxtCmnAncillaryStatus,
this.dgvTxtCmnFlowStatus,
this.dgvTxtCmnImpromedAccountNum,
this.dgvTxtCmnOpportunityId};
}
public DataGridViewColumn[] GetContractsColumns()
{
this.dgvTxtConAccount.Visible = this.DgvTxtConAccountVisable;
this.dgvTxtConAccuracyStatus.Visible = this.DgvTxtConAccuracyStatusVisable;
this.dgvTxtConCreateDate.Visible = this.DgvTxtConCreateDateVisable;
this.dgvTxtConEconomicStatus.Visible = this.DgvTxtConEconomicStatusVisable;
this.dgvTxtConHardwareStatus.Visible = this.DgvTxtConHardwareStatusVisable;
this.dgvTxtConImpromedAccNum.Visible = this.DgvTxtConImpromedAccNumVisable;
this.dgvTxtConServiceStatus.Visible = this.DgvTxtConServiceStatusVisable;
this.dgvTxtConSoftwareStatus.Visible = this.DgvTxtConSoftwareStatusVisable;
this.dgvCbxConPreProductionId.Visible = this.DgvCbxConPreProductionIdVisable;
this.dgvCbxConProductionId.Visible = this.DgvCbxConProductionVisable;
return new System.Windows.Forms.DataGridViewColumn[] {
this.dgvTxtConAccount,
this.dgvTxtConImpromedAccNum,
this.dgvTxtConCreateDate,
this.dgvTxtConAccuracyStatus,
this.dgvTxtConEconomicStatus,
this.dgvTxtConSoftwareStatus,
this.dgvTxtConServiceStatus,
this.dgvTxtConHardwareStatus,
this.dgvCbxConPreProductionId,
this.dgvCbxConProductionId,
this.dgvTxtCmnHold,
this.dgvTxtCmnConcern,
this.dgvTxtCmnAccuracyStatus,
this.dgvTxtCmnEconomicStatus,
this.dgvTxtCmnSoftwareStatus,
this.dgvTxtCmnServiceStatus,
this.dgvTxtCmnHardwareStatus,
this.dgvTxtCmnAncillaryStatus,
this.dgvTxtCmnFlowStatus,
this.dgvTxtCmnImpromedAccountNum,
this.dgvTxtCmnOpportunityId};
}
The issue is when I check a button the first time, everything shows up ok. I choose another view, everything is ok. But when I click on the first view the columns are out of order (it is like they are in reverse order but it is not exactly the same). this happens only to the first page you click on, the other two are fine. You can click off and click back on as many times as you want after those initial steps, The first list you selected at the start will be out of order the other two will be correct.
Any ideas on what could be causing this?
EDIT--
Things I have found so far:
ColumnDisplayIndexChanged fires many many times (over 200 times) when I view the first selection a second time. if the function does nothing it still loads the page, if i put a dialog box to show it fired (it was a lot of clicks) eventually i either get a big red X in the data grid view area or it loads fine (depending on the page, I get a X for pre-production but the other two loads fine (the message box still shows up hundreds of times) when you select them first)
My best guess is that this.XXX.Fill is changing the DisplayIndex value if the change is occuring after the column range creation function has returned. There are a few things you could consider however.
Create the range of columns once rather than each time a different view is selected.
Is memory an issue? If the datasets are not large and should not be large in the future you could fill 3 seperate containers and change the binding to a different container rather than refilling a single container everytime.
I think I would at the very least create the column ranges only once rather than each time.
Edit
private DataGridViewColumns[] PreProducitonColumns {get;set;}
private DataGridViewColumns[] ProductionColumns {get;set;}
private DataGridViewColumns[] ContractsColumns {get;set;}
private void Form_Load()
{
this.PreProducitonColumns = searchSettings.GetPreProductionColumns();
this.ProductionColumns = searchSettings.GetProductionColumns();
this.ContractsColumns = searchSettings.GetContractsColumns();
}
private void rbContracts_CheckedChanged(object sender, EventArgs e)
{
dgvContracts.Columns.Clear();
if (((RadioButton)sender).Checked == true)
{
if (sender == rbPreProduction)
{
dgvContracts.Columns.AddRange(PreProducitonColumns);
this.contractsBindingSource.DataMember = "Preproduction";
this.preproductionTableAdapter.Fill(this.searchDialogDataSet.Preproduction);
}
else if (sender == rbProduction)
{
dgvContracts.Columns.AddRange(ProductionColumns);
this.contractsBindingSource.DataMember = "Production";
this.productionTableAdapter.Fill(this.searchDialogDataSet.Production);
}
else if (sender == rbContracts)
{
dgvContracts.Columns.AddRange(ContractsColumns);
this.contractsBindingSource.DataMember = "Contracts";
this.contractsTableAdapter.Fill(this.searchDialogDataSet.Contracts);
}
}
}
I took the easy way out. I just created 3 DataGridView and set them visible based off of the radio button.
I have a datagridview which we will call dataGridViewExample.
My object (the uncommon datatypes is because my database is SQLite):
class MyObject
{
public Int64 Vnr { get; set; }
public string Name { get; set; }
public Single Price { get; set; }
public int Amount { get; set; }
}
Here is the relevant code:
//This form gets called with a .ShowDialog(); in my form1.
private List<MyObjecte> ExampleList = new List<MyObject>();
public MyForm()
{
dataGridViewExample.DataSource = OrdreInkøbsListe;
}
private void AddtoDataGridViewExample()
{
//Add a new MyObject to the list
ExampleList.Add(new myObject()
{
Vnr = newVnr,
Amount = newAmount,
Price = newPrice,
Name = newName
});
//refresh datasource
dataGridViewExample.DataSource = null;
dataGridViewExample.Refresh();
dataGridViewExample.DataSource = OrdreInkøbsListe;
ddataGridViewExample.Refresh();
}
When MyForm gets called with a .ShowDialog, it shows up fine and displays my DataGridView example just fine. As you can read from the code, the ExampleListis initially empty, so it just shows an empty datagridview with 4 columns: Vnr, Name, Price & Amount. If I click inside it etc. nothing happens - so everything is working as planned, so far.
Everytime I call AddtoDataGridViewExample() it adds the new object to the Datagridview, and the datagridview does update, listing all the objects added so far (they show themself as rows, again according to plan).
Now, remember that I just said that nothing happened if you clicked inside DataGridViewExample before I have called AddtoDataGridViewExample()?
Well, after having called AddtoDataGridViewExample() once or more, the program will crash if I click inside DataGridViewExample (for example: the users wants to select a row). It throws an IndexOutOfRangeException and talks about an -1 index.
It also throws the exception in the other form, on the line where I call MyForm with .ShowDialog();
I really am stuck on this, do you guys have any idea what is wrong??
My only clue is that I do believe the refresh of DataGridViewExample's datasource might be the cause of the problem.
Another important note: I have yet bound any events to my DataGridViewExample. So you can rule that idea out.
Here is all DataGridViewExample's properties:
this.dataGridViewExample.AllowUserToAddRows = false;
this.dataGridViewExample.AllowUserToDeleteRows = false;
this.dataGridViewExample.AllowUserToResizeColumns = false;
this.dataGridViewExample.AllowUserToResizeRows = false;
this.dataGridViewExample.AutoSizeColumnsMode = System.Windows.Forms.DataGridViewAutoSizeColumnsMode.Fill;
this.dataGridViewExample.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize;
this.dataGridViewExample.Location = new System.Drawing.Point(591, 53);
this.dataGridViewExample.MultiSelect = false;
this.dataGridViewExample.Name = "dataGridViewExample";
this.dataGridViewExample.ReadOnly = true;
this.dataGridViewExample.RowHeadersVisible = false;
this.dataGridViewExample.SelectionMode = System.Windows.Forms.DataGridViewSelectionMode.FullRowSelect;
this.dataGridViewExample.ShowEditingIcon = false;
this.dataGridViewExample.Size = new System.Drawing.Size(240, 150);
this.dataGridViewExample.TabIndex = 31;
I guess the click event tries to get the currently selected row and do something with it, while dataGridViewExample.DataSource = null; clears the datasource, and the currently selected row becomes null.
If you set the DataGridView.DataSource to the list, you don't need to reset it to null, refresh, and reset it to the list again (and refresh again) to see the changes. It will be enough to just refresh the DataGridView.
You can also just try using an BindingList<T> object instead of a List<T>, which will automatically notify your grid of its internal changes (Adding and removing elements), and there's also an INotifyPropertyChanged interface you can implement on your MyObject class, that will make every property change in an object show on the grid (For any changes made to the object in the code, and not through the grid itself).
Have you tried running the debugger and break when InedxOutOfRangeException is thrown to see where the exception is thrown?
Select Debug > Exceptions then there's a Find button on the dialog so you don't have to browse through all of the possibilities.
I had similar situation. I assigned generic list of certain object to DataGridView. Then I was setting null to DataSource and after that refresh. After that I assign list of objects to DataSource. While clicked on grid while runtime error occured IndexOutOfRange. My solution was to assign new empty list of my object to that grid and refresh and after changes on my working list I do assign to DataSource and call Refresh. Now, it is working without any crashes. Please look on my code before:
grid.DataSource = null;
grid.Refresh();
if(cases.Count() > 0)
{
grid.DataSource = cases;
grid.Refresh();
}
And now on my code after:
grid.DataSource = new List<MyCase>();
grid.Refresh();
//do something with cases
if(cases.Count() > 0)
{
grid.DataSource = cases;
grid.Refresh();
}