ErrorIconAlignment Enumeration
Specifies constants indicating the locations that an error icon can appear in relation to the control with an error.
[Visual Basic] <Serializable> Public Enum ErrorIconAlignment [C#] [Serializable] public enum ErrorIconAlignment [C++] [Serializable] __value public enum ErrorIconAlignment [JScript] public Serializable enum ErrorIconAlignment
Remarks
This enumeration is used by ErrorProvider.
Members
| Member name | Description |
|---|---|
| BottomLeft | The icon appears aligned with the bottom of the control and the left of the control. |
| BottomRight | The icon appears aligned with the bottom of the control and the right of the control. |
| MiddleLeft | The icon appears aligned with the middle of the control and the left of the control. |
| MiddleRight | The icon appears aligned with the middle of the control and the right of the control. |
| TopLeft | The icon appears aligned with the top of the control and to the left of the control. |
| TopRight | The icon appears aligned with the top of the control and to the right of the control. |
Example
[Visual Basic, C#, C++] The following example demonstrates using the ErrorProvider class to notify the user of a data entry error. The example creates a Form that contains a TextBox control, a NumericUpDown control, and a ComboBox control, each validating its content, and an ErrorProvider for each control. The example sets error icon options using the BlinkRate and BlinkStyle properties and the SetIconAlignment and SetIconPadding methods. The SetError method is called with or without appropriate error text during a control's Validated event, depending upon the content in the control.
[Visual Basic] Imports System Imports System.Drawing Imports System.Windows.Forms Namespace ErrorProvider Public NotInheritable Class Form1 Inherits System.Windows.Forms.Form Private label1 As System.Windows.Forms.Label Private label2 As System.Windows.Forms.Label Private label3 As System.Windows.Forms.Label Private label4 As System.Windows.Forms.Label Private label5 As System.Windows.Forms.Label Private label6 As System.Windows.Forms.Label Friend WithEvents favoriteColorComboBox As System.Windows.Forms.ComboBox Friend WithEvents nameTextBox1 As System.Windows.Forms.TextBox Friend WithEvents ageUpDownPicker As System.Windows.Forms.NumericUpDown Private ageErrorProvider As System.Windows.Forms.ErrorProvider Private nameErrorProvider As System.Windows.Forms.ErrorProvider Private favoriteColorErrorProvider As System.Windows.Forms.ErrorProvider <System.STAThread()> _ Public Shared Sub Main() System.Windows.Forms.Application.Run(New Form1()) End Sub 'Main Public Sub New() Me.nameTextBox1 = New System.Windows.Forms.TextBox() Me.label1 = New System.Windows.Forms.Label() Me.label2 = New System.Windows.Forms.Label() Me.ageUpDownPicker = New System.Windows.Forms.NumericUpDown() Me.favoriteColorComboBox = New System.Windows.Forms.ComboBox() Me.label3 = New System.Windows.Forms.Label() Me.label4 = New System.Windows.Forms.Label() Me.label5 = New System.Windows.Forms.Label() Me.label6 = New System.Windows.Forms.Label() ' Name Label Me.label1.Location = New System.Drawing.Point(56, 32) Me.label1.Size = New System.Drawing.Size(40, 23) Me.label1.Text = "Name:" ' Age Label Me.label2.Location = New System.Drawing.Point(40, 64) Me.label2.Size = New System.Drawing.Size(56, 23) Me.label2.Text = "Age (3-5)" ' Favorite Color Label Me.label3.Location = New System.Drawing.Point(24, 96) Me.label3.Size = New System.Drawing.Size(80, 24) Me.label3.Text = "Favorite color" ' ErrorBlinkStyle.AlwaysBlink Label Me.label4.Location = New System.Drawing.Point(264, 32) Me.label4.Size = New System.Drawing.Size(160, 23) Me.label4.Text = "ErrorBlinkStyle.AlwaysBlink" ' ErrorBlinkStyle.BlinkIfDifferentError Label Me.label5.Location = New System.Drawing.Point(264, 64) Me.label5.Size = New System.Drawing.Size(200, 23) Me.label5.Text = "ErrorBlinkStyle.BlinkIfDifferentError" ' ErrorBlinkStyle.NeverBlink Label Me.label6.Location = New System.Drawing.Point(264, 96) Me.label6.Size = New System.Drawing.Size(200, 23) Me.label6.Text = "ErrorBlinkStyle.NeverBlink" ' Name TextBox Me.nameTextBox1.Location = New System.Drawing.Point(112, 32) Me.nameTextBox1.Size = New System.Drawing.Size(120, 20) Me.nameTextBox1.TabIndex = 0 ' Age NumericUpDown Me.ageUpDownPicker.Location = New System.Drawing.Point(112, 64) Me.ageUpDownPicker.Maximum = New System.Decimal(New Integer() {150, 0, 0, 0}) Me.ageUpDownPicker.TabIndex = 4 ' Favorite Color ComboBox Me.favoriteColorComboBox.Items.AddRange(New Object() {"None", "Red", "Yellow", _ "Green", "Blue", "Purple"}) Me.favoriteColorComboBox.Location = New System.Drawing.Point(112, 96) Me.favoriteColorComboBox.Size = New System.Drawing.Size(120, 21) Me.favoriteColorComboBox.TabIndex = 5 ' Set up how the form should be displayed and add the controls to the form. Me.ClientSize = New System.Drawing.Size(464, 150) Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.label6, Me.label5, Me.label4, _ Me.label3, Me.favoriteColorComboBox, Me.ageUpDownPicker, Me.label2, _ Me.label1, Me.nameTextBox1}) Me.Text = "Error Provider Example" ' Create and set the ErrorProvider for each data entry control. nameErrorProvider = New System.Windows.Forms.ErrorProvider() nameErrorProvider.SetIconAlignment(Me.nameTextBox1, ErrorIconAlignment.MiddleRight) nameErrorProvider.SetIconPadding(Me.nameTextBox1, 2) nameErrorProvider.BlinkRate = 1000 nameErrorProvider.BlinkStyle = System.Windows.Forms.ErrorBlinkStyle.AlwaysBlink ageErrorProvider = New System.Windows.Forms.ErrorProvider() ageErrorProvider.SetIconAlignment(Me.ageUpDownPicker, ErrorIconAlignment.MiddleRight) ageErrorProvider.SetIconPadding(Me.ageUpDownPicker, 2) ageErrorProvider.BlinkStyle = System.Windows.Forms.ErrorBlinkStyle.BlinkIfDifferentError favoriteColorErrorProvider = New System.Windows.Forms.ErrorProvider() favoriteColorErrorProvider.SetIconAlignment(Me.ageUpDownPicker, ErrorIconAlignment.MiddleRight) favoriteColorErrorProvider.SetIconPadding(Me.ageUpDownPicker, 2) favoriteColorErrorProvider.BlinkRate = 1000 favoriteColorErrorProvider.BlinkStyle = System.Windows.Forms.ErrorBlinkStyle.NeverBlink End Sub 'New Private Sub nameTextBox1_Validated(sender As Object, e As System.EventArgs) Handles nameTextBox1.Validated If IsNameValid() Then ' Clear the error, if any, in the error provider. nameErrorProvider.SetError(Me.nameTextBox1, "") Else ' Set the error if the name is not valid. nameErrorProvider.SetError(Me.nameTextBox1, "Name is required.") End If End Sub Private Sub ageUpDownPicker_Validated(sender As Object, e As System.EventArgs) Handles ageUpDownPicker.Validated If IsAgeTooYoung() Then ' Set the error if the age is too young. ageErrorProvider.SetError(Me.ageUpDownPicker, "Age not old enough") ElseIf IsAgeTooOld() Then ' Set the error if the age is too old. ageErrorProvider.SetError(Me.ageUpDownPicker, "Age is too old") Else ' Clear the error, if any, in the error provider. ageErrorProvider.SetError(Me.ageUpDownPicker, "") End If End Sub Private Sub favoriteColorComboBox_Validated(sender As Object, e As System.EventArgs) Handles favoriteColorComboBox.Validated If Not IsColorValid() Then ' Set the error if the favorite color is not valid. favoriteColorErrorProvider.SetError(Me.favoriteColorComboBox, "Must select a color.") Else ' Clear the error, if any, in the error provider. favoriteColorErrorProvider.SetError(Me.favoriteColorComboBox, "") End If End Sub ' Functions to verify data. Private Function IsNameValid() As Boolean ' Determine whether the text box contains a zero-length string. Return nameTextBox1.Text.Length > 0 End Function Private Function IsAgeTooYoung() As Boolean ' Determine whether the age value is less than three. Return ageUpDownPicker.Value < 3 End Function Private Function IsAgeTooOld() As Boolean ' Determine whether the age value is greater than five. Return ageUpDownPicker.Value > 5 End Function Private Function IsColorValid() As Boolean ' Determine whether the favorite color has a valid value. If Not (favoriteColorComboBox.SelectedItem Is Nothing) Then If Not(favoriteColorComboBox.SelectedItem.ToString().Equals("None")) Then Return true End If End If Return false End Function End Class 'Form1 End Namespace 'ErrorProvider [C#] using System; using System.Drawing; using System.Windows.Forms; namespace ErrorProvider { public class Form1 : System.Windows.Forms.Form { private System.Windows.Forms.Label label1; private System.Windows.Forms.Label label2; private System.Windows.Forms.Label label4; private System.Windows.Forms.Label label5; private System.Windows.Forms.Label label6; private System.Windows.Forms.Label label3; private System.Windows.Forms.TextBox nameTextBox1; private System.Windows.Forms.NumericUpDown ageUpDownPicker; private System.Windows.Forms.ComboBox favoriteColorComboBox; private System.Windows.Forms.ErrorProvider ageErrorProvider; private System.Windows.Forms.ErrorProvider nameErrorProvider; private System.Windows.Forms.ErrorProvider favoriteColorErrorProvider; [STAThread] static void Main() { Application.Run(new Form1()); } public Form1() { this.nameTextBox1 = new System.Windows.Forms.TextBox(); this.label1 = new System.Windows.Forms.Label(); this.label2 = new System.Windows.Forms.Label(); this.ageUpDownPicker = new System.Windows.Forms.NumericUpDown(); this.favoriteColorComboBox = new System.Windows.Forms.ComboBox(); this.label3 = new System.Windows.Forms.Label(); this.label4 = new System.Windows.Forms.Label(); this.label5 = new System.Windows.Forms.Label(); this.label6 = new System.Windows.Forms.Label(); // Name Label this.label1.Location = new System.Drawing.Point(56, 32); this.label1.Size = new System.Drawing.Size(40, 23); this.label1.Text = "Name:"; // Age Label this.label2.Location = new System.Drawing.Point(40, 64); this.label2.Size = new System.Drawing.Size(56, 23); this.label2.Text = "Age (3-5)"; // Favorite Color Label this.label3.Location = new System.Drawing.Point(24, 96); this.label3.Size = new System.Drawing.Size(80, 24); this.label3.Text = "Favorite color"; // ErrorBlinkStyle.AlwaysBlink Label this.label4.Location = new System.Drawing.Point(264, 32); this.label4.Size = new System.Drawing.Size(160, 23); this.label4.Text = "ErrorBlinkStyle.AlwaysBlink"; // ErrorBlinkStyle.BlinkIfDifferentError Label this.label5.Location = new System.Drawing.Point(264, 64); this.label5.Size = new System.Drawing.Size(200, 23); this.label5.Text = "ErrorBlinkStyle.BlinkIfDifferentError"; // ErrorBlinkStyle.NeverBlink Label this.label6.Location = new System.Drawing.Point(264, 96); this.label6.Size = new System.Drawing.Size(200, 23); this.label6.Text = "ErrorBlinkStyle.NeverBlink"; // Name TextBox this.nameTextBox1.Location = new System.Drawing.Point(112, 32); this.nameTextBox1.Size = new System.Drawing.Size(120, 20); this.nameTextBox1.TabIndex = 0; this.nameTextBox1.Validated += new System.EventHandler(this.nameTextBox1_Validated); // Age NumericUpDown this.ageUpDownPicker.Location = new System.Drawing.Point(112, 64); this.ageUpDownPicker.Maximum = new System.Decimal(new int[] {150,0,0,0}); this.ageUpDownPicker.TabIndex = 4; this.ageUpDownPicker.Validated += new System.EventHandler(this.ageUpDownPicker_Validated); // Favorite Color ComboBox this.favoriteColorComboBox.Items.AddRange(new object[] {"None","Red","Yellow", "Green","Blue","Purple"}); this.favoriteColorComboBox.Location = new System.Drawing.Point(112, 96); this.favoriteColorComboBox.Size = new System.Drawing.Size(120, 21); this.favoriteColorComboBox.TabIndex = 5; this.favoriteColorComboBox.Validated += new System.EventHandler(this.favoriteColorComboBox_Validated); // Set up how the form should be displayed and add the controls to the form. this.ClientSize = new System.Drawing.Size(464, 150); this.Controls.AddRange(new System.Windows.Forms.Control[] { this.label6,this.label5,this.label4,this.label3, this.favoriteColorComboBox,this.ageUpDownPicker, this.label2,this.label1,this.nameTextBox1}); this.Text = "Error Provider Example"; // Create and set the ErrorProvider for each data entry control. nameErrorProvider = new System.Windows.Forms.ErrorProvider(); nameErrorProvider.SetIconAlignment (this.nameTextBox1, ErrorIconAlignment.MiddleRight); nameErrorProvider.SetIconPadding (this.nameTextBox1, 2); nameErrorProvider.BlinkRate = 1000; nameErrorProvider.BlinkStyle = System.Windows.Forms.ErrorBlinkStyle.AlwaysBlink; ageErrorProvider = new System.Windows.Forms.ErrorProvider(); ageErrorProvider.SetIconAlignment (this.ageUpDownPicker, ErrorIconAlignment.MiddleRight); ageErrorProvider.SetIconPadding (this.ageUpDownPicker, 2); ageErrorProvider.BlinkStyle = System.Windows.Forms.ErrorBlinkStyle.BlinkIfDifferentError; favoriteColorErrorProvider = new System.Windows.Forms.ErrorProvider(); favoriteColorErrorProvider.SetIconAlignment (this.ageUpDownPicker, ErrorIconAlignment.MiddleRight); favoriteColorErrorProvider.SetIconPadding (this.ageUpDownPicker, 2); favoriteColorErrorProvider.BlinkRate = 1000; favoriteColorErrorProvider.BlinkStyle = System.Windows.Forms.ErrorBlinkStyle.NeverBlink; } private void nameTextBox1_Validated(object sender, System.EventArgs e) { if(IsNameValid()) { // Clear the error, if any, in the error provider. nameErrorProvider.SetError(this.nameTextBox1, ""); } else { // Set the error if the name is not valid. nameErrorProvider.SetError(this.nameTextBox1, "Name is required."); } } private void ageUpDownPicker_Validated(object sender, System.EventArgs e) { if (IsAgeTooYoung()) { // Set the error if the age is too young. ageErrorProvider.SetError(this.ageUpDownPicker, "Age not old enough"); } else if (IsAgeTooOld()) { // Set the error if the age is too old. ageErrorProvider.SetError(this.ageUpDownPicker, "Age is too old"); } else { // Clear the error, if any, in the error provider. ageErrorProvider.SetError(this.ageUpDownPicker, ""); } } private void favoriteColorComboBox_Validated(object sender, System.EventArgs e) { if (!IsColorValid()) { // Set the error if the favorite color is not valid. favoriteColorErrorProvider.SetError(this.favoriteColorComboBox, "Must select a color."); } else { // Clear the error, if any, in the error provider. favoriteColorErrorProvider.SetError(this.favoriteColorComboBox, ""); } } // Functions to verify data. private bool IsNameValid() { // Determine whether the text box contains a zero-length string. return (nameTextBox1.Text.Length > 0); } private bool IsAgeTooYoung() { // Determine whether the age value is less than three. return (ageUpDownPicker.Value < 3); } private bool IsAgeTooOld() { // Determine whether the age value is greater than five. return (ageUpDownPicker.Value > 5 ); } private bool IsColorValid() { // Determine whether the favorite color has a valid value. return ((favoriteColorComboBox.SelectedItem != null) && (!favoriteColorComboBox.SelectedItem.ToString().Equals("None"))); } } } [C++] #using <mscorlib.dll> #using <System.dll> #using <System.Windows.Forms.dll> #using <System.Drawing.dll> using namespace System; using namespace System::Drawing; using namespace System::Windows::Forms; public __gc class Form1 : public System::Windows::Forms::Form { private: System::Windows::Forms::Label* label1; System::Windows::Forms::Label* label2; System::Windows::Forms::Label* label4; System::Windows::Forms::Label* label5; System::Windows::Forms::Label* label6; System::Windows::Forms::Label* label3; System::Windows::Forms::TextBox* nameTextBox1; System::Windows::Forms::NumericUpDown* ageUpDownPicker; System::Windows::Forms::ComboBox* favoriteColorComboBox; System::Windows::Forms::ErrorProvider* ageErrorProvider; System::Windows::Forms::ErrorProvider* nameErrorProvider; System::Windows::Forms::ErrorProvider* favoriteColorErrorProvider; public: Form1() { this->nameTextBox1 = new System::Windows::Forms::TextBox(); this->label1 = new System::Windows::Forms::Label(); this->label2 = new System::Windows::Forms::Label(); this->ageUpDownPicker = new System::Windows::Forms::NumericUpDown(); this->favoriteColorComboBox = new System::Windows::Forms::ComboBox(); this->label3 = new System::Windows::Forms::Label(); this->label4 = new System::Windows::Forms::Label(); this->label5 = new System::Windows::Forms::Label(); this->label6 = new System::Windows::Forms::Label(); // Name Label this->label1->Location = System::Drawing::Point(56, 32); this->label1->Size = System::Drawing::Size(40, 23); this->label1->Text = S"Name:"; // Age Label this->label2->Location = System::Drawing::Point(40, 64); this->label2->Size = System::Drawing::Size(56, 23); this->label2->Text = S"Age (3-5)"; // Favorite Color Label this->label3->Location = System::Drawing::Point(24, 96); this->label3->Size = System::Drawing::Size(80, 24); this->label3->Text = S"Favorite color"; // ErrorBlinkStyle::AlwaysBlink Label this->label4->Location = System::Drawing::Point(264, 32); this->label4->Size = System::Drawing::Size(160, 23); this->label4->Text = S"ErrorBlinkStyle::AlwaysBlink"; // ErrorBlinkStyle::BlinkIfDifferentError Label this->label5->Location = System::Drawing::Point(264, 64); this->label5->Size = System::Drawing::Size(200, 23); this->label5->Text = S"ErrorBlinkStyle::BlinkIfDifferentError"; // ErrorBlinkStyle::NeverBlink Label this->label6->Location = System::Drawing::Point(264, 96); this->label6->Size = System::Drawing::Size(200, 23); this->label6->Text = S"ErrorBlinkStyle::NeverBlink"; // Name TextBox this->nameTextBox1->Location = System::Drawing::Point(112, 32); this->nameTextBox1->Size = System::Drawing::Size(120, 20); this->nameTextBox1->TabIndex = 0; this->nameTextBox1->Validated += new System::EventHandler(this, &Form1::nameTextBox1_Validated); // Age NumericUpDown this->ageUpDownPicker->Location = System::Drawing::Point(112, 64); int temp0 __gc [] = {150, 0, 0, 0}; this->ageUpDownPicker->Maximum = System::Decimal(temp0); this->ageUpDownPicker->TabIndex = 4; this->ageUpDownPicker->Validated += new System::EventHandler(this, &Form1::ageUpDownPicker_Validated); // Favorite Color ComboBox Object* temp1 [] = {S"None", S"Red", S"Yellow", S"Green", S"Blue", S"Purple"}; this->favoriteColorComboBox->Items->AddRange(temp1); this->favoriteColorComboBox->Location = System::Drawing::Point(112, 96); this->favoriteColorComboBox->Size = System::Drawing::Size(120, 21); this->favoriteColorComboBox->TabIndex = 5; this->favoriteColorComboBox->Validated += new System::EventHandler(this, &Form1::favoriteColorComboBox_Validated); // Set up how the form should be displayed and add the controls to the form. this->ClientSize = System::Drawing::Size(464, 150); System::Windows::Forms::Control* temp2 [] = {this->label6, this->label5, this->label4, this->label3, this->favoriteColorComboBox, this->ageUpDownPicker, this->label2, this->label1, this->nameTextBox1}; this->Controls->AddRange(temp2); this->Text = S"Error Provider Example"; // Create and set the ErrorProvider for each data entry control. nameErrorProvider = new System::Windows::Forms::ErrorProvider(); nameErrorProvider->SetIconAlignment (this->nameTextBox1, ErrorIconAlignment::MiddleRight); nameErrorProvider->SetIconPadding (this->nameTextBox1, 2); nameErrorProvider->BlinkRate = 1000; nameErrorProvider->BlinkStyle = System::Windows::Forms::ErrorBlinkStyle::AlwaysBlink; ageErrorProvider = new System::Windows::Forms::ErrorProvider(); ageErrorProvider->SetIconAlignment (this->ageUpDownPicker, ErrorIconAlignment::MiddleRight); ageErrorProvider->SetIconPadding (this->ageUpDownPicker, 2); ageErrorProvider->BlinkStyle = System::Windows::Forms::ErrorBlinkStyle::BlinkIfDifferentError; favoriteColorErrorProvider = new System::Windows::Forms::ErrorProvider(); favoriteColorErrorProvider->SetIconAlignment (this->ageUpDownPicker, ErrorIconAlignment::MiddleRight); favoriteColorErrorProvider->SetIconPadding (this->ageUpDownPicker, 2); favoriteColorErrorProvider->BlinkRate = 1000; favoriteColorErrorProvider->BlinkStyle = System::Windows::Forms::ErrorBlinkStyle::NeverBlink; } private: void nameTextBox1_Validated(Object* /*sender*/, System::EventArgs* /*e*/) { if (IsNameValid()) { // Clear the error, if any, in the error provider. nameErrorProvider->SetError(this->nameTextBox1, S""); } else { // Set the error if the name is not valid. nameErrorProvider->SetError(this->nameTextBox1, S"Name is required."); } } void ageUpDownPicker_Validated(Object* /*sender*/, System::EventArgs* /*e*/) { if (IsAgeTooYoung()) { // Set the error if the age is too young. ageErrorProvider->SetError(this->ageUpDownPicker, S"Age not old enough"); } else if (IsAgeTooOld()) { // Set the error if the age is too old. ageErrorProvider->SetError(this->ageUpDownPicker, S"Age is too old"); } else { // Clear the error, if any, in the error provider. ageErrorProvider->SetError(this->ageUpDownPicker, S""); } } void favoriteColorComboBox_Validated(Object* /*sender*/, System::EventArgs* /*e*/) { if (!IsColorValid()) { // Set the error if the favorite color is not valid. favoriteColorErrorProvider->SetError(this->favoriteColorComboBox, S"Must select a color."); } else { // Clear the error, if any, in the error provider. favoriteColorErrorProvider->SetError(this->favoriteColorComboBox, S""); } } // Functions to verify data. bool IsNameValid() { // Determine whether the text box contains a zero-length String*. return (nameTextBox1->Text->Length > 0); } bool IsAgeTooYoung() { // Determine whether the age value is less than three. return (ageUpDownPicker->Value < 3); } bool IsAgeTooOld() { // Determine whether the age value is greater than five. return (ageUpDownPicker->Value > 5); } bool IsColorValid() { // Determine whether the favorite color has a valid value. return ((favoriteColorComboBox->SelectedItem != 0) && (!favoriteColorComboBox->SelectedItem->Equals(S"None"))); } }; [STAThread] int main() { Application::Run(new Form1()); }
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Requirements
Namespace: System.Windows.Forms
Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
See Also
System.Windows.Forms Namespace | ErrorProvider | ErrorBlinkStyle | BlinkRate