I Have a WinForm with 2 Text boxes to input ServerName and Database, RadioButtons to switch between providers, and 1 Button to build ConnectionStrings depending of inputs.
_ServerName and _DatabaseName are Global variables.
I would like to build the connection string outside the Form and get the result returned to a label control in my Form,
the code in my external class is as next:
public static string _ServerName { get; set; }
public static string _Base { get; set; }
public static SqlConnection _Con { get; set; }
static void ConOption1()
{
Global._Con = new SqlConnection();
Global._Con.ConnectionString = #"data source=" + Global._ServerName + "; initial catalog=" + Global._Base + "; Integrated Security=True";
}
The code in my form (Form1) is:
private void button1_Click(object sender, EventArgs e)
{
Global._ServerName = textBox1.Text;
Global._Base = textBox2.Text;
ConOption1();
label1.Text = Global._Con.ToString();
}
The problem here is that I cannot call conOption1 from Form1 to get the built string in Label1.text, thanks for your help.
You did not mark ConOption1 as being public.
What do you exactly mean by "I cannot call conOption1 to get the built string"? The compiler not only won't compile your code but will also point at the exact problem. There is no point in asking the question on SO "Where is the error", as the compiler already told you where is the error.
Related
I tried using a parameter with Catel's Command:
public Command MyCommand { get; private set; }
MyCommand = new Command(MyCommand_Execute);
private void MyCommand_Execute(object parameter)
{
}
and get the following error:
The best overloaded method match for
'Catel.MVVM.Command.Command(System.Action, System.Func, object)'
has some invalid arguments
I followed the sample Catel code, any ideas?
The finalize this question with an actual answer:
Use the generic implementation of the Command class, which is Command:
public Command<int> MyCommand { get; private set; }
MyCommand = new Command<int>(MyCommand_Execute);
private void MyCommand_Execute(int parameter)
{
}
I'm working on a WPF project which includes update/delete/insert operation on many tables. For simplicity, I use a datagrid for each table. The users can operate on these tables directly. Once done, click a button, the tables in database get updated. Twoway bind is perfect in this case. Below code seems working fine.
However, one thing I do not like is: the _DBConnection is always open. It is closed until the form exists. Usually, I always open connection whenever I need to, use it, close it immediately.
So, my question is: is below code the correct way to do the twoway bind?
thanks
public partial class MainWindow : Window
{
private OleDbConnection _DBConnection;
private OleDbDataAdapter _DataAdapterAdmin;
private DataSet _DataSetAdmin;
public MainWindow()
{
InitializeComponent();
}
private void InitAdminGrid()
{
string cmd = "SELECT * FROM Admin ORDER BY LastName";
_DataAdapterAdmin = new OleDbDataAdapter(cmd, _DBConnection);
_DataSetAdmin = new DataSet();
_DataAdapterAdmin.Fill(_DataSetAdmin);
dgAdministration.BeginInit();
dgAdministration.DataContext = _DataSetAdmin.Tables[0];
dgAdministration.Items.Refresh();
dgAdministration.EndInit();
}
private void MainWindow_Loaded(object sender, RoutedEventArgs e)
{
string connectionString = clsDataAccess.GetConnectionString();
_DBConnection = new OleDbConnection(connectionString);
_DBConnection.Open();
InitAdminGrid();
}
private void btnStart_Click(object sender, RoutedEventArgs e)
{
try
{
OleDbCommandBuilder cmd = new OleDbCommandBuilder(_DataAdapterAdmin);
_DataAdapterAdmin.Update(_DataSetAdmin);
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString(), "Exception", MessageBoxButton.OK, MessageBoxImage.Error);
}
}
private void MainWindow_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
if (_DBConnection != null)
{
_DBConnection.Close();
_DBConnection.Dispose();
}
}
}
I have the following Global class file:
Global.cs
public static class Global
{
private static string _globalVar = "";
public static string GlobalVar
{
get { return _globalVar; }
set { _globalVar = value; }
}
}
I set the new value of string GlobarVar in Form1.cs as '1234'.
Form1.cs
public Form1()
{
InitializeComponent();
Global.GlobalVar = "1234";
}
I tried to display the value to Form2.cs using the message box
public Form2()
{
InitializeComponent();
MessageBox.Show(Global.GlobalVar); // displays blank values
}
Am I missing something?
Four options:
You're not constructing Form1 before you construct Form2
Something else is setting Global.GlobalVar back to null or an empty string
Your forms are in different app domains, so they'll have entirely separate Global types
You're running the application twice; static variables don't live on across different processes
It's hard to tell which of these is the case, but personally I'd try to avoid using global state to start with. It's a pain for testability and reasoning about how your program works.
Try your property page (file Global.cs) like these:
public class Global
{
private static string _globalVar;
public string GlobalVar
{
get { return _globalVar; }
set { _globalVar = value; }
}
}
Our winforms application has long allowed a "print" option which basically uses RDLC.
The customer has requested that we add a feature allowing users to send the "printed" output via email.
Now, we know that an EMF file is created (in the TEMP folder) as a sort of hidden byproduct of our current printing process.
Seems to us we can simply grab this EMF file and attach it to a new email and the job is done.
Is this the best option?
Can we rely on an EMF file be opened by any Windows machine?
How we identify the EMF file? ... just seems to be named %TEMP%\DiaryGrid_1.emf currently. OK so DiaryGrid is the name of our RDLC file but the _1 gets added somewhere along the way.
I did it before. I did it exporting programatically the report to a pdf to a specific location, then we email the pdf file and delete it. I will try to find the code for you (Not in home now)
EDITED:
Sorry for the later. Now i'm in home and I will give you some code blocks that I think will give you some help to acomplish your task. I will include some comments to the code so you can understand some things that are specific in my project. This code are tested and are working well in my clients, but i'm sure that it can be improved. Please, let me know if you can improve this code ;)
First of all, we will export the report to pdf.
private string ExportReportToPDF(string reportName)
{
Warning[] warnings;
string[] streamids;
string mimeType;
string encoding;
string filenameExtension;
byte[] bytes = ReportViewer1.LocalReport.Render(
"PDF", null, out mimeType, out encoding, out filenameExtension,
out streamids, out warnings);
string filename = Path.Combine(Path.GetTempPath(), reportName);
using (var fs = new FileStream(filename, FileMode.Create))
{
fs.Write(bytes, 0, bytes.Length);
fs.Close();
}
return filename;
}
Now, we need a class that control the Mail system. Every mail system has their own caracteristics, so maybe you will need modify this class. The behaviour of the class is simple. You only need to fill the properties, and call the Send method. In my case, windows don't let me delete the pdf file once I send it (Windows says the file is in use), so I program the file to be deleted in the next reboot. Take a look to the delete method. Please, note that the send method use a cutom class named MailConfig. This is a small class that has some config strings like Host, User Name, and Password. The mail will be send using this params.
public class Mail
{
public string Title { get; set; }
public string Text { get; set; }
public string From { get; set; }
public bool RequireAutentication { get; set; }
public bool DeleteFilesAfterSend { get; set; }
public List<string> To { get; set; }
public List<string> Cc { get; set; }
public List<string> Bcc { get; set; }
public List<string> AttachmentFiles { get; set; }
#region appi declarations
internal enum MoveFileFlags
{
MOVEFILE_REPLACE_EXISTING = 1,
MOVEFILE_COPY_ALLOWED = 2,
MOVEFILE_DELAY_UNTIL_REBOOT = 4,
MOVEFILE_WRITE_THROUGH = 8
}
[DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
static extern bool MoveFileEx(string lpExistingFileName,
string lpNewFileName,
MoveFileFlags dwFlags);
#endregion
public Mail()
{
To = new List<string>();
Cc = new List<string>();
Bcc = new List<string>();
AttachmentFiles = new List<string>();
From = MailConfig.Username;
}
public void Send()
{
var client = new SmtpClient
{
Host = MailConfig.Host,
EnableSsl = false,
};
if (RequireAutentication)
{
var credentials = new NetworkCredential(MailConfig.Username,
MailConfig.Password);
client.Credentials = credentials;
}
var message = new MailMessage
{
Sender = new MailAddress(From, From),
From = new MailAddress(From, From)
};
AddDestinataryToList(To, message.To);
AddDestinataryToList(Cc, message.CC);
AddDestinataryToList(Bcc, message.Bcc);
message.Subject = Title;
message.Body = Text;
message.IsBodyHtml = false;
message.Priority = MailPriority.High;
var attachments = AttachmentFiles.Select(file => new Attachment(file));
foreach (var attachment in attachments)
message.Attachments.Add(attachment);
client.Send(message);
if (DeleteFilesAfterSend)
AttachmentFiles.ForEach(DeleteFile);
}
private void AddDestinataryToList(IEnumerable<string> from,
ICollection<MailAddress> mailAddressCollection)
{
foreach (var destinatary in from)
mailAddressCollection.Add(new MailAddress(destinatary, destinatary));
}
private void DeleteFile(string filepath)
{
// this should delete the file in the next reboot, not now.
MoveFileEx(filepath, null, MoveFileFlags.MOVEFILE_DELAY_UNTIL_REBOOT);
}
}
Now, you can create a form to ask for the destinataries, add some validation, etc, return to you an instance of the Mail class... or you can simply "hard code" the values and fill the class.
Here is the code that I use in a button to call this form, in my example it is named SendMailView.
private void BtnSendByMail_Click(object sender, EventArgs e)
{
SendMailView sendMailView = new SendMailView();
if (sendMailView.ShowDialog()== DialogResult.OK)
{
Mail mail = sendMailView.CurrentItem;
mail.AttachmentFiles.Add(ExportReportToPDF("Invoice.pdf"));
mail.DeleteFilesAfterSend = true;
mail.RequireAutentication = true;
mail.Send();
}
sendMailView.Dispose();
}
In this example senMailView.CurrentItem is the instance of the mail class. We simply need to call to the Send methis and the work is done.
This is the largest answer I ever wrote in SO... I hope it help you :D If you have any problem using it, call me. By the way, i'm not very proud of my english, so forgive me if the text has any mistake.
I'm trying to drag data from the Winforms portion of my application on a WPF controls that's contained inside an "ElementHost". And it crashes when I try doing so.
Trying the same thing but from Winforms to Winforms works fine. (See example code below)
I need help on making this work... have any clues what I'm doing wrong?
Thanks!
Example:
In the sample code below, I'm just trying to drag a custom MyContainerClass object created when initating the drag on the label control on a 1) System.Windows.Forms.TextBox (Winforms) and 2) System.Windows.TextBox (WPF, added to an ElementHost).
Case 1) works fine but case 2) is crashing when trying to retrieve the drop data using GetData(). GetDataPresent("WindowsFormsApplication1.MyContainerClass") returns "true" so In theory, I should be able to retrive my drop data of that type like in Winforms.
Here is the stack trace of the crash:
"Error HRESULT E_FAIL has been returned from a call to a COM component" with the following stack trace:
at System.Runtime.InteropServices.Marshal.ThrowExceptionForHRInternal(Int32 errorCode, IntPtr errorInfo)
at System.Windows.Forms.DataObject.GetDataIntoOleStructs(FORMATETC& formatetc, STGMEDIUM& medium)
at System.Windows.Forms.DataObject.System.Runtime.InteropServices.ComTypes.IDataObject.GetDataHere(FORMATETC& formatetc, STGMEDIUM& medium)
at System.Windows.Forms.DataObject.System.Runtime.InteropServices.ComTypes.IDataObject.GetData(FORMATETC& formatetc, STGMEDIUM& medium)
at System.Windows.DataObject.OleConverter.GetDataInner(FORMATETC& formatetc, STGMEDIUM& medium)
at System.Windows.DataObject.OleConverter.GetDataFromOleHGLOBAL(String format, DVASPECT aspect, Int32 index)
at System.Windows.DataObject.OleConverter.GetDataFromBoundOleDataObject(String format, DVASPECT aspect, Int32 index)
at System.Windows.DataObject.OleConverter.GetData(String format, Boolean autoConvert, DVASPECT aspect, Int32 index)
at System.Windows.DataObject.OleConverter.GetData(String format, Boolean autoConvert)
at System.Windows.DataObject.GetData(String format, Boolean autoConvert)
at System.Windows.DataObject.GetData(String format)
at WindowsFormsApplication1.Form1.textBox_PreviewDragEnter(Object sender, DragEventArgs e) in WindowsFormsApplication1\WindowsFormsApplication1\Form1.cs:line 48
Here is some code:
// -- Add an ElementHost to your form --
// -- Add a label to your form --
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
System.Windows.Controls.TextBox textBox = new System.Windows.Controls.TextBox();
textBox.Text = "WPF TextBox";
textBox.AllowDrop = true;
elementHost2.Child = textBox;
textBox.PreviewDragEnter += new System.Windows.DragEventHandler(textBox_PreviewDragEnter);
System.Windows.Forms.TextBox wfTextBox = new System.Windows.Forms.TextBox();
wfTextBox.Text = "Winforms TextBox";
wfTextBox.AllowDrop = true;
wfTextBox.DragEnter += new DragEventHandler(wfTextBox_DragEnter);
Controls.Add(wfTextBox);
}
void wfTextBox_DragEnter(object sender, DragEventArgs e)
{
bool dataPresent = e.Data.GetDataPresent("WindowsFormsApplication1.MyContainerClass");
// NO CRASH here!
object data = e.Data.GetData("WindowsFormsApplication1.MyContainerClass");
}
void textBox_PreviewDragEnter(object sender, System.Windows.DragEventArgs e)
{
bool dataPresent = e.Data.GetDataPresent("WindowsFormsApplication1.MyContainerClass");
// Crash appens here!!
// {"Error HRESULT E_FAIL has been returned from a call to a COM component."}
object data = e.Data.GetData("WindowsFormsApplication1.MyContainerClass");
}
private void label1_MouseDown(object sender, MouseEventArgs e)
{
label1.DoDragDrop(new MyContainerClass(label1.Text), DragDropEffects.Copy);
}
}
public class MyContainerClass
{
public object Data { get; set; }
public MyContainerClass(object data)
{
Data = data;
}
}
#Pedery & jmayor: Thanks for the suggestions guys! (see my findings below)
After quite a few experimentation, trials and errors, and a bit of "Reflector'ing", I managed to figure out exactly why I was receiving the cryptic error message "Error HRESULT E_FAIL has been returned from a call to a COM component".
It was due to the fact that when dragging data WPF <-> Winforms in a same app, that data has to be Serializable!
I've checked how difficult it would be to transform all of our classes to "Serializable" and I would have a been a real pain for a couple of reasons... one, we would need to practically make all of classes serializable and two, some of these classes have references to Controls! And Controls aren't serializable. So a major refactoring would have been needed.
So... since we wanted to pass any object of any class to drag from/to WPF inside the same application, I decided to create a wrapper class, with the Serializable attribute and implementing ISerializable. I would have 1 contructor with 1 parameter of type "object" which would be the actual drag data. That wrapper, when serializing/de-serializing, would serialize not the object itself... but rather the IntPtr to the object (which we can do since we only want that functionnality inside our 1 instance only application.) See code sample below:
[Serializable]
public class DataContainer : ISerializable
{
public object Data { get; set; }
public DataContainer(object data)
{
Data = data;
}
// Deserialization constructor
protected DataContainer(SerializationInfo info, StreamingContext context)
{
IntPtr address = (IntPtr)info.GetValue("dataAddress", typeof(IntPtr));
GCHandle handle = GCHandle.FromIntPtr(address);
Data = handle.Target;
handle.Free();
}
#region ISerializable Members
public void GetObjectData(SerializationInfo info, StreamingContext context)
{
GCHandle handle = GCHandle.Alloc(Data);
IntPtr address = GCHandle.ToIntPtr(handle);
info.AddValue("dataAddress", address);
}
#endregion
}
To keep the IDataObject functionnality, I created the following DataObject wrapper:
public class DataObject : IDataObject
{
System.Collections.Hashtable _Data = new System.Collections.Hashtable();
public DataObject() { }
public DataObject(object data)
{
SetData(data);
}
public DataObject(string format, object data)
{
SetData(format, data);
}
#region IDataObject Members
public object GetData(Type format)
{
return _Data[format.FullName];
}
public bool GetDataPresent(Type format)
{
return _Data.ContainsKey(format.FullName);
}
public string[] GetFormats()
{
string[] strArray = new string[_Data.Keys.Count];
_Data.Keys.CopyTo(strArray, 0);
return strArray;
}
public string[] GetFormats(bool autoConvert)
{
return GetFormats();
}
private void SetData(object data, string format)
{
object obj = new DataContainer(data);
if (string.IsNullOrEmpty(format))
{
// Create a dummy DataObject object to retrieve all possible formats.
// Ex.: For a System.String type, GetFormats returns 3 formats:
// "System.String", "UnicodeText" and "Text"
System.Windows.Forms.DataObject dataObject = new System.Windows.Forms.DataObject(data);
foreach (string fmt in dataObject.GetFormats())
{
_Data[fmt] = obj;
}
}
else
{
_Data[format] = obj;
}
}
public void SetData(object data)
{
SetData(data, null);
}
#endregion
}
And we are using the above classes like this:
myControl.DoDragDrop(new MyNamespace.DataObject(myNonSerializableObject));
// in the drop event for example
e.Data.GetData(typeof(myNonSerializableClass));
I know I know... it's not very pretty... but it's doing what we wanted. We also created a dragdrop helper class which masks the DataObject creation and has templated GetData functions to retrieve the data without any cast... a bit like:
myNonSerializableClass newObj = DragDropHelper.GetData<myNonSerializableClass>(e.Data);
So thanks again for the replies! You guys gave me good ideas where to look at for possible solutions!
-Oli
I had a "similar" issue some time ago so I can at least tell you what I found out.
It seems .Net is resorting to OLE remoting when drag/drop operations are performed in but the simplest of cases. For some reason GetDataPresent will in these cases be successful and GetData will fail. This is furthermore mystified by the fact that there are several versions of the IDataObject in the .Net framework.
Windows Forms defaults to System.Windows.Forms.IDataObject. However, in your case you could try to give System.Runtime.InteropServices.ComTypes.IDataObject a shot instead. You can also check out my discussion here.
Hope this helps.
Seems wonderfull at first sight. I tried it but got some errors on implementations.
I began to correct some errors when I decided to look for something a little bit more simplier, that do not have pointers (humm I don't like that, particularly with carbage collection, but I have no idea if it could have real impact) and that do not use Interop.
I come up with that. It works for me and I hope it will work for anybody else. It is only intended to be used for local drag drop (inside the same app).
How to use to drag:
DragDrop.DoDragDrop(listBoxOfAvailableScopes, new DragDropLocal(GetSelectedSimulResultScopes()),
DragDropEffects.Copy);
How to use to drop (get):
DragDropLocal dragDropLocal = (DragDropLocal)e.Data.GetData(typeof(DragDropLocal));
SimulResultScopes simulResultScopes = (SimulResultScopes)dragDropLocal.GetObject();
Code:
namespace Util
{
[Serializable]
public class DragDropLocal
{
private static readonly Dictionary<Guid, object> _dictOfDragDropLocalKeyToDragDropSource = new Dictionary<Guid, object>();
private Guid _guid = Guid.NewGuid();
public DragDropLocal(object objToDrag)
{
_dictOfDragDropLocalKeyToDragDropSource.Add(_guid, objToDrag);
}
public object GetObject()
{
object obj;
_dictOfDragDropLocalKeyToDragDropSource.TryGetValue(_guid, out obj);
return obj;
}
~DragDropLocal()
{
_dictOfDragDropLocalKeyToDragDropSource.Remove(_guid);
}
}
}
Maybe the events are in the opposite way. The PreviewDragEnter should be related with the WPFTextBox. Also watch out the DragEventArgs class. There is one in System.Windows.Form ( Windows Form version) and the one under System.Windows( for WPF version).