ErrorProvider.GetError(Control) Method
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Returns the current error description string for the specified control.
public:
System::String ^ GetError(System::Windows::Forms::Control ^ control);
public string GetError (System.Windows.Forms.Control control);
member this.GetError : System.Windows.Forms.Control -> string
Public Function GetError (control As Control) As String
- control
- Control
The item to get the error description string for.
The error description string for the specified control.
control
is null
.
The following code example uses the GetError method to check for an error before opening a file dialog box. To run this example, paste the following code into a form containing a TextBox named TextBox1
, an OpenFileDialog named OpenFileDialog1
, a button named Button1
, and an ErrorProvider named ErrorProvider1
. Ensure all events are associated with their event handlers.
private:
void TextBox1_Validating( Object^ sender,
System::ComponentModel::CancelEventArgs^ e )
{
// If nothing is entered,
// an ArgumentException is caught; if an invalid directory is entered,
// a DirectoryNotFoundException is caught. An appropriate error message
// is displayed in either case.
try
{
System::IO::DirectoryInfo^ directory = gcnew System::IO::DirectoryInfo( TextBox1->Text );
directory->GetFiles();
ErrorProvider1->SetError( TextBox1, "" );
}
catch ( System::ArgumentException^ )
{
ErrorProvider1->SetError( TextBox1, "Please enter a directory" );
}
catch ( System::IO::DirectoryNotFoundException^ )
{
ErrorProvider1->SetError( TextBox1, "The directory does not exist."
"Try again with a different directory." );
}
}
// This method handles the LostFocus event for TextBox1 by setting the
// dialog's InitialDirectory property to the text in TextBox1.
void TextBox1_LostFocus( Object^ sender, System::EventArgs^ e )
{
OpenFileDialog1->InitialDirectory = TextBox1->Text;
}
// This method demonstrates using the ErrorProvider.GetError method
// to check for an error before opening the dialog box.
void Button1_Click( System::Object^ sender, System::EventArgs^ e )
{
//If there is no error, then open the dialog box.
if ( ErrorProvider1->GetError( TextBox1 )->Equals( "" ) )
{
::DialogResult dialogResult = OpenFileDialog1->ShowDialog();
}
}
private void textBox1_Validating(object sender,
System.ComponentModel.CancelEventArgs e)
{
// If nothing is entered,
// an ArgumentException is caught; if an invalid directory is entered,
// a DirectoryNotFoundException is caught. An appropriate error message
// is displayed in either case.
try
{
System.IO.DirectoryInfo directory =
new System.IO.DirectoryInfo(textBox1.Text);
directory.GetFiles();
errorProvider1.SetError(textBox1, "");
}
catch(System.ArgumentException ex1)
{
errorProvider1.SetError(textBox1, "Please enter a directory");
}
catch(System.IO.DirectoryNotFoundException ex2)
{
errorProvider1.SetError(textBox1, "The directory does not exist." +
"Try again with a different directory.");
}
}
// This method handles the LostFocus event for textBox1 by setting the
// dialog's InitialDirectory property to the text in textBox1.
private void textBox1_LostFocus(object sender, System.EventArgs e)
{
openFileDialog1.InitialDirectory = textBox1.Text;
}
// This method demonstrates using the ErrorProvider.GetError method
// to check for an error before opening the dialog box.
private void button1_Click(System.Object sender, System.EventArgs e)
{
//If there is no error, then open the dialog box.
if (errorProvider1.GetError(textBox1)=="")
{
DialogResult dialogResult = openFileDialog1.ShowDialog();
}
}
Private Sub TextBox1_Validating(ByVal sender As Object, _
ByVal e As System.ComponentModel.CancelEventArgs) _
Handles TextBox1.Validating
' If nothing is entered,
' an ArgumentException is caught; if an invalid directory is entered,
' a DirectoryNotFoundException is caught. An appropriate error message
' is displayed in either case.
Try
Dim directory As New System.IO.DirectoryInfo(TextBox1.Text)
directory.GetFiles()
ErrorProvider1.SetError(TextBox1, "")
Catch ex1 As System.ArgumentException
ErrorProvider1.SetError(TextBox1, "Please enter a directory")
Catch ex2 As System.IO.DirectoryNotFoundException
ErrorProvider1.SetError(TextBox1, _
"The directory does not exist." & _
"Try again with a different directory.")
End Try
End Sub
' This method handles the LostFocus event for TextBox1 by setting the
' dialog's InitialDirectory property to the text in TextBox1.
Private Sub TextBox1_LostFocus(ByVal sender As Object, _
ByVal e As System.EventArgs) Handles TextBox1.LostFocus
OpenFileDialog1.InitialDirectory = TextBox1.Text
End Sub
' This method demonstrates using the ErrorProvider.GetError method
' to check for an error before opening the dialog box.
Private Sub Button1_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles Button1.Click
'If there is no error, then open the dialog box.
If ErrorProvider1.GetError(TextBox1) = "" Then
Dim dialogResult As DialogResult = OpenFileDialog1.ShowDialog()
End If
End Sub
Продукт | Версії |
---|---|
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
Windows Desktop | 3.0, 3.1, 5, 6, 7, 8, 9 |
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