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Display String in a Database as a Checkbox

I have a Windows Form that was mainly made using the graphical editor. It is connected to a database called, Database1. One of the tables in the database is called Table1, and contains the column CheckBox1. When I connected the form to the database, Database1DataSet.xsd and Database1DataSet.Designer.cs were automatically created.
CheckBox1 can either hold "Yes" or blank (this wasn't my decision). I would like to make a checkbox checked if the value in the CheckBox1 column is "Yes", and unchecked if the value is blank. If I drag a bound checkbox onto the form, it doesn't work because I assume that the values in the column need to be either 1 or 0. So I'm trying to work around this.
In my form, I have the following
// Form Constructor
public myForm()
{
// Initializes all the components in the form
InitializeComponent();
// Change the checkboxes checked state
this.myCheckBox.Checked = myCheckBox_Update();
}
// Method for determining if the checkbox should be checked
private bool myCheckBox_Update()
{
// This SHOULD bring in the current record of the database
DataRowView current = (DataRowView)this.Table1BindingSource.Current;
try
{
// This SHOULD determine if the value in the CheckBox1 field has a value
return current.Row["CheckBox1"].ToString().Length > 0;
}
catch (NullReferenceException ex)
{
MessageBox.Show("NullReferenceException was thrown!", "Error");
return false;
}
}
In the InitializeComponent() function, there is the following
// This line is generated when I drag a bound checkbox to the form
// this.myCheckBox.DataBindings.Add(new System.Windows.Forms.Binding("CheckState", this.Table1BindingSource, "CheckBox1", true));
// For the miscellaneous information about the checkbox
this.myCheckBox.AutoSize = true;
this.myCheckBox.Location = new System.Drawing.Point(3, 3);
this.myCheckBox.Name = "myCheckBox";
this.myCheckBox.Size = new System.Drawing.Size(92, 23);
this.myCheckBox.TabIndex = 0;
this.myCheckBox.Text = "Check Box";
this.myCheckBox.UseVisualStyleBackColor = true;
However, it keeps throwing a NullReferenceException. I'm assuming that this is because this.Table1BindingSource.Current cannot be cast as a DataRowView.
I have looked at several other posts on SO that are somewhat related to this problem (e.g. This post, or this post), but I haven't found anything that has worked so far. The second link's answer doesn't work because I am iterating through the records with this.Table1BindingSource.MoveNext();, and I won't know the index.
Can someone steer me in the right direction? I'd really appreciate it
EDIT: The BindingSource is initialized with this
private System.Windows.Forms.BindingSource Table1BindingSource;
this.Table1BindingSource = new System.Windows.Forms.BindingSource(this.components);

I'll put this in an answer since it's not fit for a comment.
You may also try checking the value for null in your try statement.
try
{
// This SHOULD determine if the value in the CheckBox1 field has a value
object val = current.Row["CheckBox1"];
if (val == null)
{
return false;
}
else
{
return current.Row["CheckBox1"].ToString().Length > 0;
}
}
Or at least set a breakpoint at the if (val == null) statement and make sure val has a value that you would expect.
If by 'blank' you mean a String.Empty, then your code would work as you expect it to, but if blank means null, then you'll have to check for null, you can't call ToString() on a null value.

What I ended up doing is just changing the values in my database from "Yes" and blank to 1 and 0. Then in the InitializeComponent() method, I added the following line (or it might be generated for you if you drag it from the data source panel)
this.myCheckBox.DataBindings.Add(new System.Windows.Forms.Binding("CheckState", this.Table1BindingSource, "CheckBox1", true));

Delete data using 2 DialogForm

hi i have question for remove data from 2 forms dialog
in first dialogform it's contain list of data, and in second dialogform it's contain detail of data and delete button... i already successfully delete data in database but i confused how to remove data from list...
if just select data and delete i know it's can be done with this code
quizzes.RemoveAt(listBoxQuizzes.SelectedIndex);
but problem here in dialogform1 not available button delete, just view details data. so if user want to delete data, he must open dialogform2 (detail data)
i already done delete data in database with this code
Global.deleteData("DELETE FROM Quiz_Occurrences WHERE ID = " + id);
and close detaildataform (dialogform2) by
this.Close();
and move to dialogform1 (listdatabox)
the problem in here, data which just i delete still in there because it's still not remove yet (already delete from database but not remove from list). and need to restart program to see effect of delete data
Update Progress
i changed data to global var, so it's technically i can remove data in dialogform2
this is code (modifier listbox in dialogform1)
int no = 1;
foreach (CQuizOccurrence myQuizOccurrence in Global.quizOccurrences) {
}
if i want to delete it from dialogform1, i can use
Global.quizOccurrences.removeAT(listBoxQuizzes.SelectedIndex);
but if i want to delete it from dialogform2
Global.quizOccurrences.removeAT(.........); //still not have idea how can i reference index
Update solution from #nitin
so first i write in formdialog2
public Frmdialog1 frm_dialog { get; set; }
then i write this in formdialog1
frmdialog2.frm_dialog=this;
then back again to formdialog1 to write
frm_dialog.quizzes.RemoveAt(frm_dialog.listBoxQuizzes.SelectedIndex);
is that right because i get many error

If you are opening second dialog from first one u can Have property in Frmdialog2 like
public Frmdialog1 frm_dialog { get; set; }
After creating object of Frmdialog2 in Frmdialog1 you can set this property as
frmdialog2.frm_dialog=this;
Now u can remove item from this listbox in Frmdialog2 iteself after deleting record from database as
frm_dialog.quizzes.RemoveAt(frm_dialog.listBoxQuizzes.SelectedIndex);
NOTE: Modifier for your listbox should be public

i'm finally be able to do as i want after ask many different question about this topic
first i try to change var to global, so i can remove data in listbox dialogform1 from dialogform2 (i think it's the easiest way)
//in dialog form1
foreach (CQuizOccurrence myQuizOccurrence in Global.quizOccurrences) {
//load data from Global.quizOccurences
}
//call function close to close dialogform1
then in dialogform2, match Global.quizOccurrences data with date&time detail data (using list & foreach)
List<CQuizOccurrence> matchData = new List<CQuizOccurrence>();
foreach (CQuizOccurrence myQuizOccurrence in Global.quizOccurrences)
{
DateTime dtDatabase = (DateTime)myQuizOccurrence.occurred;
string dt = dtDatabase.ToString();
if (dt == dateOccur) {
matchData.Add(myQuizOccurrence);
}
}
foreach (CQuizOccurrence myQuizOccurrence in matchData)
{
Global.quizOccurrences.Remove(myQuizOccurrence);
}
//call function show dialog for formdialog1

form1 could subscibe to the form2's close event.
inside form1
form2 f2dialog = new form2(/*I guess you are passing data here*/);
f2.dialog.Closing += eventhandler;
somewhere else
void eventhandler(object sender, eventargs e)
{
//refresh globaldata since by now you have ran delete query
//rebind or call listbox.items.refresh() or both <-------------this how do you get data from rver? the server is updated but does global know that?
}
then you need to call code to get data from database again. and rebind to data
listbox.datacontext = Global.GetData();//or however this is done
you have to manually reset this eveerytime you change your database
databinding is not as smart as you think it is.

ASP.NET Chart Click, Pass Data and in New Tab

I am trying to get an asp.net chart and it's legend to allow me to open up another page in another tab passing the values of the piece of the chart I clicked on with it. I have been able to get it to open up another tab when clicking on the chart by doing the following but it does not pass the data.
Chart2.Series[0].LegendUrl = "chartdetails.aspx";
Chart2.Series[0].Url = "chartdetails.aspx";
Chart2.Series[0].LegendMapAreaAttributes="target=\"_blank\"";
Chart2.Series[0].LegendPostBackValue = "#VALY-#VALX";
Chart2.Series[0].MapAreaAttributes="target=\"_blank\"";
Chart2.Series[0].PostBackValue = "#VALY-#VALX";
If I leave out the urls and mapareaattributes I can then get it to go to the onclick where I am able to get the data, put it in a session variable and use Reponse.Redirect to open the new page where it sees the session variable data,however it doesn't open in another tab, it opens in the same tab.
Chart2.Series[0].LegendPostBackValue = "#VALY-#VALX";
Chart2.Series[0].PostBackValue = "#VALY-#VALX";
protected void Chart2_Click(object sender, ImageMapEventArgs e)
{
HttpContext.Current.Session["VAL"] = e.PostBackValue;
Response.Redirect("chartdetails.aspx", false);
}
How can I get it to do both? Does Response.Redirect have a way to open a new tab? Some research leads me to believe it does not. Is there a way to get both the server side onclick event to run, so I can set the session variable and the chart.series.url to fire after the server side click runs so the session variable would be set before I open the new tab?
I'm feeling like this may be a case of "I can't have my cake and eat it too."

As it turns out I can have my cake and eat it too. If I set the url, postbackvalues, and legendmapareaattributes in my Page_Load and set up the click for the chart to put the PostBackValue in the session variable when you click on the chart it saves the value in the session variable that is listed in the PostBackValue of the Series of the chart. It then opens in a new tab chartdetails.aspx where I can access the information from the session variable.
Chart2.Series[0].LegendUrl = "chartdetails.aspx";
Chart2.Series[0].LabelUrl = "chartdetails.aspx";
Chart2.Series[0].Url = "chartdetails.aspx";
Chart2.Series[0].LegendPostBackValue = "#VALY-#VALX";
Chart2.Series[0].LabelPostBackValue = "#VALY-#VALX";
Chart2.Series[0].PostBackValue = "#VALY-#VALX";
Chart2.Series[0].LegendMapAreaAttributes = "target=\"_blank\"";
Chart2.Series[0].LabelMapAreaAttributes = "target=\"_blank\"";
Chart2.Series[0].MapAreaAttributes="target=\"_blank\"";
protected void Chart2_Click(object sender, ImageMapEventArgs e)
{
HttpContext.Current.Session["VAL"] = e.PostBackValue;
}

I can't use postback to get the value on the series for some reason. So, I want to share my way inspired by #Adam that is loop over the series points after data binding the chart and set URL.
GET:
Series s=new Series("Test");
/*
* After Data bind to the series s
*/
for (int p = 0; p < s.Points.Count; p++)
{
s.Points[p].Url ="test.aspx?name1=value1&name2=value2";
s.Points[p].MapAreaAttributes = "target=\"_blank\"";
}
POST:
(I put javascript function in url. So, It will execute the javascript for me to send a form I created in the function to the text.aspx.)
Series s=new Series("Test");
/*
* After Data bind to the series s
*/
for (int p = 0; p < s.Points.Count; p++)
{
s.Points[p].Url ="javascript:(function(){" +
"var mapForm = document.createElement('form');mapForm.target = '_blank';" +
"mapForm.method = 'POST';mapForm.action = 'test.aspx';" +
"var mapInput = document.createElement('input');mapInput.type = 'hidden';" +
"mapInput.name = 'partID';mapInput.value = 'put any value you need';" +
"mapForm.appendChild(mapInput);document.body.appendChild(mapForm);" +
"mapForm.submit();document.body.removeChild(mapForm);})();";
}
Reference:
Javascript pass values using POST

ASP.net with C# List increment on postback

I have an odd problem. In my program, a user manipulates dropdown boxes and presses an ADD button to fill in a listbox with the selected items. Eventually, I send these items to a MYSQL database with an INSERT command. When the user is hitting the ADD button, the items are added to a generic List and the listbox, and on postback everything seems fine and I can add stuff all day long. However, when I hit the Submit/save button, to send the data to the server, the list keeps copying the added data over and over again to itself on every postback no matter what causes the postback. I can see the result in the lstbox, and I can see the List.count going up.
I have no code in my page_load section. I do use a session property thing to hold the List data though.
public List<string> activityProp
{
get
{
if (HttpContext.Current.Session["codelist"] == null)
{
HttpContext.Current.Session["codelist"] = new List<string>();
}
return HttpContext.Current.Session["codelist"] as List<string>;
}
set
{
HttpContext.Current.Session["codelist"] = value;
}
}
and here is the code for the button. The sqlsetter() method just has a generic SQL command structure in it with an insert string. It is only fired from this button.
protected void cmdSave_Click(object sender, EventArgs e)
{
//this will use the 'test' class to do a rule check on the day
test therules = new test();
bool comp = therules.check(dayProp, timeProp, activityProp);
if (comp == true)
{
lblComp.Text = "You're ok!";
lblComp.ForeColor = Color.Green;
lblError.Text = "";
SQLdaysetter();
}
else
{
string zeerror = therules.getError();
lblComp.Text = "You're not ok!";
lblError.Text = "at " + zeerror;
lblComp.ForeColor = Color.Red;
lblError.ForeColor = Color.Red;
}
}
SQL stuff:
using (MySqlConnection conn = new MySqlConnection(ConfigurationManager.ConnectionStrings["theConnectionString"].ConnectionString))
{
conn.Open();
using (MySqlCommand cmdIns = new MySqlCommand(sqlstate, conn))
{
cmdIns.ExecuteNonQuery();
cmdIns.Dispose();
}
conn.Close();
}
Maybe this stuff isn't even related to the problem, any ideas where to look?

I had some things in the OnInit event and evidently they were getting run every time the page reloaded. I'm still not sure why
Jake, take 10 minutes and read up on the Page Life Cycle (especially the events section). It will save you valuable time in the future.
http://msdn.microsoft.com/en-us/library/ms178472.aspx

BindingSource sees changes, DataTable doesn't

I have recently switched over from Java/RMI to C# / .net, and am working on my first project using databinding to update records in Oracle. On this first form I'm building, I have a detail view for vehicle records (VIN, year/make/model, license plate number, that sort of thing). The first thing I did in terms of writing to the DB was saving updates:
private void btn_saveDesc_Click(object sender, EventArgs e)
{
bool isSaved = false;
hJA_VEHICLEBindingSource.EndEdit();
DataSet1.HJA_VEHICLEDataTable ch =
(DataSet1.HJA_VEHICLEDataTable)dataSet1.HJA_VEHICLE.GetChanges();
if (ch == null)
{
MessageBox.Show("There are no changes to save.");
}
else
{
Service<TVDDataService.IService1>.Use(svcProxy =>
{
isSaved = svcProxy.SaveVehicles(ch);
});
if (isSaved)
{
// update the vehicle in the local dataset
var modifiedRows = from row in dataSet1.HJA_VEHICLE
where row.RowState == DataRowState.Modified
select row;
foreach (DataRow row in modifiedRows)
{
row.Delete();
}
dataSet1.HJA_VEHICLE.Merge(ch);
dataSet1.HJA_VEHICLE.AcceptChanges();
}
if(isSaved)
{
MessageBox.Show("The record has been saved.");
}
else
{
MessageBox.Show("The record could not be saved.");
}
}
}
That all seemed ok, so I moved on to adding new records. I made a button (I saw online where various people had said it was as good or better to make your own than use a binding navigator) and put this in its handler:
DataRowView drv = (DataRowView)hJA_VEHICLEBindingSource.AddNew();
currVeh_id = nextID(); // generate arbitrary ID for the record
drv["VEH_ID"] = currVeh_id;
drv["GRNTE_ID"] = lastSelectedGranteeID; // just to have an initial value
hJA_VEHICLEBindingSource.Filter = "VEH_ID = " + currVeh_id;
So there (above) I'm putting initial values into some required columns (VEH_ID is the PK). Then I ran the app, entered a value in the textbox for VIN, and went to save (same code as above) and this time GetChanges() returned null.
So I tried this in the "add new" button handler, in place of the first thing:
DataSet1.HJA_VEHICLERow newRow =
(DataSet1.HJA_VEHICLERow)dataSet1.HJA_VEHICLE.NewRow();
currVeh_id = nextID();
newRow.VEH_ID = currVeh_id;
newRow.GRNTE_ID = lastSelectedGranteeID;
dataSet1.HJA_VEHICLE.AddHJA_VEHICLERow(newRow);
hJA_VEHICLEBindingSource.Filter = "VEH_ID = " + currVeh_id;
Now I have something really interesting happening.
- I can successfully enter and save data on any number of new records, until I select an existing record. If I move to an existing record and then add a new record, then when I go to save the new record, the values that were explicitly set in code get written to the DB but data entered into the GUI do not "take" for the new record.
- I can successfully change any number of existing records, until I enter a new record. If I add one or more new records, save, and then try to save changes to an existing record, the call to GetChanges() returns null (so again, apparently it is not "seeing" what's been entered through the GUI).
So in both of these cases, the change from old to new, or new to old, appears to introduce some condition that makes the datatable unaware of what was entered into the GUI. But in changing from old to new it only takes selecting an existing record, whereas with changing from new to old, it only breaks after saving (if I do a new record but then abandon it without saving, I can modify existing records without problems).
I added this into the save handler, just prior to the actual save (in a loop because ch is a datatable, but really the code is set up to where you have to either save or abandon the new record before moving on - thus the loop only executes once):
foreach (DataSet1.HJA_VEHICLERow r in ch)
{
DataRowView drv = (DataRowView)hJA_VEHICLEBindingSource.Current;
MessageBox.Show(drv["VIN_ID"].ToString());
MessageBox.Show(r.VEH_ID + "\n" + r.GRNTE_ID + "\n'"
+ r.VIN_ID + "'");
}
Where VIN_ID is the column to which this particular textbox is bound (I tried this with other fields on the form too, to verify it wasn't just something flaky about that one textbox). The first message box (DataRowView from the binding source) shows the vin that I entered into the textbox. The second message box (row from the table returned by GetChanges()) shows the empty string for VIN_ID, although it has the correct (set through code) values for VEH_ID and GRNTE_ID. The same thing happens if I select a different value for GRNTE_ID using the combo box bound to that column; the row from the datatable still has the value that was set through code, "unaware" of the value selected through the GUI.
Why would the datatable and binding source have different values for the same field? And why would the datatable be able to "see" values entered through the GUI only until the user switches from existing to new, or from new to existing?
Thanks.
Angel:
I'm doing that in my Service:
public bool SaveVehicles(DataSet1.HJA_VEHICLEDataTable vehicles)
{
bool saved = false;
if (vehicles != null && !vehicles.HasErrors)
{
HJA_VEHICLETableAdapter ta = new HJA_VEHICLETableAdapter();
int result = ta.Update(vehicles);
saved = (result > 0);
}
return saved;
}
This is called from this block from my original post:
Service<TVDDataService.IService1>.Use(svcProxy =>
{
isSaved = svcProxy.SaveVehicles(ch);
});
Johannes:
The call to EndEdit() is the second line in the save handler (near the top of my post). Should I be calling it somewhere else as well?
Thanks.
Just to clarify: SaveVehicles cannot be the source of the problem, since the problem is appearing before SaveVehicles is ever called. What condition could cause a discrepancy between the BindingSource and the DataTable after EndEdit() has been called and before anything actually writes to the DB?

You have to update your table adapter after use EndEdit(); also you can update your complete DataSet with the follow snippet :
this.BindingSource1.EndEdit();
this.TableAdapter1.Update(this.DataSet1);
Hopes Helps...

*IF you are using a BindingSource as well:
Just do a simple BindingSource.EndEdit() and your TextBox data will be sent over to the DataTable.
Example:-
_bsHeader.EndEdit();
if (_dsHeader.HasChanges())
{
DataTable dsInsert = _dsHeader.GetChanges(DataRowState.Added).Copy();
_objDal.Insert(dsInsert);
}
Hope this helps anyone who stumbles here.