Control::CausesValidation Property
Gets or sets a value indicating whether the control causes validation to be performed on any controls that require validation when it receives focus.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
Property Value
Type: System::Booleantrue if the control causes validation to be performed on any controls requiring validation when it receives focus; otherwise, false. The default is true.
If the CausesValidation property is set to false, the Validating and Validated events are suppressed.
The CausesValidation property value is typically set to false for controls such as a Help button.
The following code example uses the derived class TextBox and validates an e-mail address that the user enters. If the e-mail address is not in the standard format (containing "@" and "."), the validation fails, an ErrorProvider icon is displayed, and the event is canceled. One of the buttons on the form has its CausesValidation property set to false. Clicking or setting focus to this button does not trigger validation. This example requires that a TextBox, an ErrorProvider control, and a Button have been created on a form.
public: Form1() { InitializeComponent(); //Set button2 to be non-validating. this->button2->CausesValidation = false; } private: void textBox1_Validating( Object^ sender, System::ComponentModel::CancelEventArgs^ e ) { String^ errorMsg; if ( !ValidEmailAddress( textBox1->Text, &errorMsg ) ) { // Cancel the event and select the text to be corrected by the user. e->Cancel = true; textBox1->Select( 0, textBox1->Text->Length ); // Set the ErrorProvider error with the text to display. this->errorProvider1->SetError( textBox1, errorMsg ); } } void textBox1_Validated( Object^ sender, System::EventArgs^ e ) { // If all conditions have been met, clear the ErrorProvider of errors. errorProvider1->SetError( textBox1, "" ); } public: bool ValidEmailAddress( String^ emailAddress, [Out]interior_ptr<String^> errorMessage ) { // Confirm that the e-mail address String* is not empty. if ( emailAddress->Length == 0 ) { *errorMessage = "e-mail address is required."; return false; } // Confirm that there is an "@" and a "." in the e-mail address, and in the correct order. if ( emailAddress->IndexOf( "@" ) > -1 ) { if ( emailAddress->IndexOf( ".", emailAddress->IndexOf( "@" ) ) > emailAddress->IndexOf( "@" ) ) { *errorMessage = ""; return true; } } *errorMessage = "e-mail address must be valid e-mail address format.\n" + "For example 'someone@example.com' "; return false; }
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.