|
So I have implemented the binary tree shown here (http://msdn.microsoft.com/en-us/library/ms379572.aspx[^]). I have no prior knowledge in I/O and its related areas, so any quick reads would be nice.
My question is, how would i save the tree (including the root as well as the internal and leaf nodes) into a file? How would i use the file after its saved? I have a decoder (just a simple program that traverses all of the tree's nodes and writes them out in console), but I would have no idea how to recall the file and decode it.
Any help is appreciated.
|
|
|
|
|
You might be able to use xml serialization to save and load the binary tree.
|
|
|
|
|
What I would do is firstly save the traversal. Pre / Post. And then the data. .Net makes IO easy. Try the StreamWriter and StreamReader classes
Stephen Lintott Bsc IT (RAU)
|
|
|
|
|
I want to be able to have the user select between two radio buttons. This will determine what page is loaded into a webbrowser object on part of the form. I even tried simple buttons, but the webbrowser only loads the first Url loaded. If button1 is selected first then only the url for button1 is loaded requardless of how many times button2 is pressed and etc for the other url. Is there something I need to set for the webBrowse object? This is annoying because it seems simple, but somehow isn't working.
modified on Friday, September 5, 2008 9:38 AM
|
|
|
|
|
Well I figured it out. Seems I had the AllowNavigation property set to false on the webBrowser control. silly me. Works now.
|
|
|
|
|
When you figure out the answer to a question that you post here, change the header of the original message to end with some variation of "SOLVED".
"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001
|
|
|
|
|
I'm creating a simple C# print class... this print class doesn't actually does the printing but more on layout and inserting objects into the page that is to be printed. You can insert objects in the page using the X-axis and Y-axis of the page.. No problems with that except that the Size and Height of the font is not relative to the X and Y axis cause i'm trying to insert a line break and i need the height of the text with the font used. How do I convert the height to something like Dots Per Inch?
|
|
|
|
|
hi
use the PrinterUnitConvert class in the System.Drawing.Printing namespace.
regards
|
|
|
|
|
Hi
I've added a crystal report in my project & added tables of my sql server database in that report. In the display section of the crystal report, I also added the column of the tables those i want to display in my report. Now, I am querying the database and binding the dataset to report but my reports always shows no records. I've checked my code by debugging & there are always 4 recods in the table of the dataset but my reports shows nothing. My code is here:
string query = "SELECT AccountBalanceLog.[Date], Company.CompanyName, Accounts.AccountNo, AccountBalanceLog.BalanceIn, AccountBalanceLog.BalanceOut FROM AccountBalanceLog INNER JOIN Accounts ON AccountBalanceLog.AccountNo = Accounts.AccountNo INNER JOIN Company ON Accounts.CompanyID = Company.CompanyID INNER JOIN Employee ON Accounts.EmployeeID = Employee.EmployeeID WHERE Employee.EmployeeID='1' AND Company.CompanyID='2' AND Accounts.AccountNo='Oanda1'";
SqlConnection Conn = new SqlConnection(MyConnectionString.ConnectionString);
SqlCommand myCommand = new SqlCommand(query, Conn);
Conn.Open();
SqlDataAdapter adp = new SqlDataAdapter(myCommand);
DataSet ds = new DataSet();
adp.Fill(ds);
ReportDocument doc = new ReportDocument();
string cwd = System.IO.Directory.GetCurrentDirectory();
if (cwd.EndsWith("\\bin\\Debug"))
{
cwd = cwd.Replace("\\bin\\Debug", "");
}
doc.FileName = cwd + "\\CrystalReport2.rpt";
doc.SetDataSource(ds);
crystalReportViewer1.ReportSource = doc;
Conn.Close();
please guide me where is am missing something.
thanks in advance...
Regards...
Mudasser Hassan
|
|
|
|
|
I'm using this code(see below)to import data from an excel spreadsheet into my database.now the problem is that it throws "Object reference not set to an instance of an object"exception whenever it gets to this line
Microsoft.Office.Interop.Excel.Workbook theWorkbook = ExcelObj.Workbooks.Open(ofd.FileName, 0, true, 5,
"", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows,"\t", false, false, 0, true, true, true);
what am i missing or what am i doing wrong? plz help
public void ImportToStudent()
{
try
{
//Gets the filename, not the path
string filename = ofd.SafeFileName;
string connection = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + "E:\\..\\PSAtechZTimetableSystem\\SpreadSheet.xls" + "; Extended Properties='Excel 8.0; IMEX=1; HDR=YES'";
// Here is the call to Open a Workbook in Excel
// It uses most of the default values (except for the read-only which we set to true)
Microsoft.Office.Interop.Excel.Workbook theWorkbook = ExcelObj.Workbooks.Open(ofd.FileName, 0, true, 5,
"", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows,"\t", false, false, 0, true, true, true);
// get the collection of sheets in the workbook
Microsoft.Office.Interop.Excel.Sheets sheets = theWorkbook.Worksheets;
// get the first and only worksheet from the collection of worksheets
Microsoft.Office.Interop.Excel.Worksheet worksheet = (Microsoft.Office.Interop.Excel.Worksheet)sheets.get_Item(1);
using (SqlConnection conPSAtechZ = new SqlConnection(connection))
{
conPSAtechZ.ConnectionString = connection;
using (SqlCommand commandExcel = conPSAtechZ.CreateCommand())
{
System.Data.DataTable table = new System.Data.DataTable();
commandExcel.CommandText = "SELECT [StudentID] AS [StudentID]," + "[ModuleCode] AS [ModuleCode], " + "FROM [Sheet1$]";
//Open the Excel Connection
conPSAtechZ.Open();
using (SqlDataReader dr = commandExcel.ExecuteReader(CommandBehavior.CloseConnection))
{
while (dr.Read() && dr.HasRows)
{
lblResults.Text = "Importing...";
try
{
studentdal.RegisterStudents(new RegisterStudent(Convert.ToString(dr["StudentID"]), Convert.ToString(dr["ModuleCode"])));
commandExcel.CommandType = CommandType.StoredProcedure;
lblResults.Text = "Successfully Imported!!";
}
catch (Exception Ex)
{
MessageBox.Show("Error!!\n " + Ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
dr.Close();
}
}
}
}
catch (Exception EX)
{
MessageBox.Show("The spreadsheet is not in the correct format!\n\n" + EX.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
|
|
|
|
|
Twyce wrote: I'm using this code(see below)to import data from an excel spreadsheet into my database.now the problem is that it throws "Object reference not set to an instance of an object"exception whenever it gets to this line
Microsoft.Office.Interop.Excel.Workbook theWorkbook = ExcelObj.Workbooks.Open(ofd.FileName, 0, true, 5,
"", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows,"\t",
false, false, 0, true, true, true);
what am i missing or what am i doing wrong? plz help
It means that one of the objects you're trying to access is null. Start your application in the debugger, step into this line (it'll automatically when throwing the exception) and see which of them is null.
modified 12-Sep-18 21:01pm.
|
|
|
|
|
It's likely the variable ofd is null when you reach the error line.
Mark Brock
"We're definitely not going to make a G or a PG version of this. It's not PillowfightCraft." -- Chris Metzen
Click here to view my blog
|
|
|
|
|
You posted "twyce" 
|
|
|
|
|
I'm using this code(see below)to import data from an excel spreadsheet into my database.now the problem is that it throws "Object reference not set to an instance of an object"exception whenever it gets to this line
Microsoft.Office.Interop.Excel.Workbook theWorkbook = ExcelObj.Workbooks.Open(ofd.FileName, 0, true, 5,
"", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows,"\t", false, false, 0, true, true, true);
what am i missing or what am i doing wrong? plz help
public void ImportToStudent()
{
try
{
//Gets the filename, not the path
string filename = ofd.SafeFileName;
string connection = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + "E:\\..\\PSAtechZTimetableSystem\\SpreadSheet.xls" + "; Extended Properties='Excel 8.0; IMEX=1; HDR=YES'";
// Here is the call to Open a Workbook in Excel
// It uses most of the default values (except for the read-only which we set to true)
Microsoft.Office.Interop.Excel.Workbook theWorkbook = ExcelObj.Workbooks.Open(ofd.FileName, 0, true, 5,
"", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows,"\t", false, false, 0, true, true, true);
// get the collection of sheets in the workbook
Microsoft.Office.Interop.Excel.Sheets sheets = theWorkbook.Worksheets;
// get the first and only worksheet from the collection of worksheets
Microsoft.Office.Interop.Excel.Worksheet worksheet = (Microsoft.Office.Interop.Excel.Worksheet)sheets.get_Item(1);
using (SqlConnection conPSAtechZ = new SqlConnection(connection))
{
conPSAtechZ.ConnectionString = connection;
using (SqlCommand commandExcel = conPSAtechZ.CreateCommand())
{
System.Data.DataTable table = new System.Data.DataTable();
commandExcel.CommandText = "SELECT [StudentID] AS [StudentID]," + "[ModuleCode] AS [ModuleCode], " + "FROM [Sheet1$]";
//Open the Excel Connection
conPSAtechZ.Open();
using (SqlDataReader dr = commandExcel.ExecuteReader(CommandBehavior.CloseConnection))
{
while (dr.Read() && dr.HasRows)
{
lblResults.Text = "Importing...";
try
{
studentdal.RegisterStudents(new RegisterStudent(Convert.ToString(dr["StudentID"]), Convert.ToString(dr["ModuleCode"])));
commandExcel.CommandType = CommandType.StoredProcedure;
lblResults.Text = "Successfully Imported!!";
}
catch (Exception Ex)
{
MessageBox.Show("Error!!\n " + Ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
dr.Close();
}
}
}
}
catch (Exception EX)
{
MessageBox.Show("The spreadsheet is not in the correct format!\n\n" + EX.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
|
|
|
|
|
 Please edit your post and use <pre></pre> tags
|
|
|
|
|
Hi
any ideas of how to do this?
I have data in a MDB, and i want to import the data to a SQL Database
I need to upload it in a ASP.Net page coded in C#, copy to the SQL Server and then, delete the file.
Any ideas?
I tried some code and make it work, but gives me an error when i try to delete the file (it says that the file is being used for other process). So i want to know if there is another way to do this.
thanks
|
|
|
|
|
Did you close all the connections before trying to delete the database file?
|
|
|
|
|
Yes, i closed all the connections before deleting the database. 
|
|
|
|
|
Greetings Comrades,
Does anybody knows how to clear Stream?
Stream memoryStream = new MemoryStream();
...
memoryStream.Flush() - does nothing
memoryStream.SetLength(0) - calls AccessViolationException ("memory is corrupt")
Any help will be just fine. Thanks!!!
One nation - underground
|
|
|
|
|
you close and dispose it.
|
|
|
|
|
Did you use this :
memoryStream.Dispose();
|
|
|
|
|
But in this case am I able to continue using MemoryStream ?
One nation - underground
|
|
|
|
|
Nope. The only way to clear it out is to Seek to position 0 and write 0's to every known position. Depending on the size of the Stream, it's porobably going to be faster, or at least easier, to just kill the existing stream and create a new one.
|
|
|
|
|
Thank you.
One nation - underground
|
|
|
|
|
Try this out
MemoryStream ms = new MemoryStream();
.......
......
ms.SetLength(0);
ms.Position = 0;
Hope this Works!!! 
|
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
