VB.NET ErrorProvider.SetError方法代碼示例

' 導入命名空間
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

        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.favoriteColorComboBox, ErrorIconAlignment.MiddleRight)
            favoriteColorErrorProvider.SetIconPadding(Me.favoriteColorComboBox, 2)
            favoriteColorErrorProvider.BlinkRate = 1000
            favoriteColorErrorProvider.BlinkStyle = System.Windows.Forms.ErrorBlinkStyle.NeverBlink
        End Sub
 
        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, String.Empty)
            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, String.Empty)
            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, String.Empty)
            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 (favoriteColorComboBox.SelectedItem IsNot Nothing) Then
                    If Not(favoriteColorComboBox.SelectedItem.ToString().Equals("None")) Then
                        Return true 
                    End If
            End If
            Return false
        End Function 

    End Class
End Namespace 'ErrorProvider

' 導入命名空間
Imports System.Windows.Forms

public class DeferredValidation
   public Shared Sub Main
        Application.Run(New Form1)
   End Sub
End class


Public Class Form1
    Private Sub TextBox1_Validating(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles TextBox1.Validating, TextBox2.Validating, TextBox3.Validating
        If (TextBox1.Text.Length <> 0) And Not (TextBox1.Text Like "##") _
        Then
            ErrorProvider1.SetError(TextBox1, TextBox1.Name & " must contain exactly two digits")
        Else
            ErrorProvider1.SetError(TextBox1, "")
        End If

    End Sub

    Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
        e.Cancel = True
        If IsInvalidField(TextBox1) Then Exit Sub
        If IsInvalidField(TextBox3) Then Exit Sub
        e.Cancel = False
    End Sub

    Private Function IsInvalidField(ByVal ctl As Control) As Boolean
        If ErrorProvider1.GetError(ctl).Length = 0 Then
            Return False
        Else
            MessageBox.Show(ErrorProvider1.GetError(ctl))
            ctl.Focus()
            Return True
        End If
    End Function
End Class

<Global.Microsoft.VisualBasic.CompilerServices.DesignerGenerated()> _
Partial Public Class Form1
    Inherits System.Windows.Forms.Form

    'Form overrides dispose to clean up the component list.
    <System.Diagnostics.DebuggerNonUserCode()> _
    Protected Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing AndAlso components IsNot Nothing Then
            components.Dispose()
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.  
    'Do not modify it using the code editor.
    <System.Diagnostics.DebuggerStepThrough()> _
    Private Sub InitializeComponent()
        Me.components = New System.ComponentModel.Container
        Me.Label1 = New System.Windows.Forms.Label
        Me.TextBox1 = New System.Windows.Forms.TextBox
        Me.TextBox2 = New System.Windows.Forms.TextBox
        Me.Label2 = New System.Windows.Forms.Label
        Me.TextBox3 = New System.Windows.Forms.TextBox
        Me.Label3 = New System.Windows.Forms.Label
        Me.ErrorProvider1 = New System.Windows.Forms.ErrorProvider(Me.components)
        CType(Me.ErrorProvider1, System.ComponentModel.ISupportInitialize).BeginInit()
        Me.SuspendLayout()
        '
        'Label1
        '
        Me.Label1.AutoSize = True
        Me.Label1.Location = New System.Drawing.Point(8, 8)
        Me.Label1.Name = "Label1"
        Me.Label1.Size = New System.Drawing.Size(56, 13)
        Me.Label1.TabIndex = 0
        Me.Label1.Text = "Five Digits"
        '
        'TextBox1
        '
        Me.TextBox1.Location = New System.Drawing.Point(72, 8)
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.Size = New System.Drawing.Size(80, 20)
        Me.TextBox1.TabIndex = 1
        '
        'TextBox2
        '
        Me.TextBox2.Location = New System.Drawing.Point(72, 32)
        Me.TextBox2.Name = "TextBox2"
        Me.TextBox2.Size = New System.Drawing.Size(80, 20)
        Me.TextBox2.TabIndex = 3
        '
        'Label2
        '
        Me.Label2.AutoSize = True
        Me.Label2.Location = New System.Drawing.Point(8, 32)
        Me.Label2.Name = "Label2"
        Me.Label2.Size = New System.Drawing.Size(56, 13)
        Me.Label2.TabIndex = 2
        Me.Label2.Text = "Five Digits"
        '
        'TextBox3
        '
        Me.TextBox3.Location = New System.Drawing.Point(72, 56)
        Me.TextBox3.Name = "TextBox3"
        Me.TextBox3.Size = New System.Drawing.Size(80, 20)
        Me.TextBox3.TabIndex = 5
        '
        'Label3
        '
        Me.Label3.AutoSize = True
        Me.Label3.Location = New System.Drawing.Point(8, 56)
        Me.Label3.Name = "Label3"
        Me.Label3.Size = New System.Drawing.Size(56, 13)
        Me.Label3.TabIndex = 4
        Me.Label3.Text = "Five Digits"
        '
        'ErrorProvider1
        '
        Me.ErrorProvider1.ContainerControl = Me
        '
        'Form1
        '
        Me.AutoScaleDimensions = New System.Drawing.SizeF(6.0!, 13.0!)
        Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
        Me.ClientSize = New System.Drawing.Size(210, 83)
        Me.Controls.Add(Me.TextBox3)
        Me.Controls.Add(Me.Label3)
        Me.Controls.Add(Me.TextBox2)
        Me.Controls.Add(Me.Label2)
        Me.Controls.Add(Me.TextBox1)
        Me.Controls.Add(Me.Label1)
        Me.Name = "Form1"
        Me.Text = "Deferred Validation"
        CType(Me.ErrorProvider1, System.ComponentModel.ISupportInitialize).EndInit()
        Me.ResumeLayout(False)
        Me.PerformLayout()

    End Sub
    Friend WithEvents Label1 As System.Windows.Forms.Label
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
    Friend WithEvents TextBox2 As System.Windows.Forms.TextBox
    Friend WithEvents Label2 As System.Windows.Forms.Label
    Friend WithEvents TextBox3 As System.Windows.Forms.TextBox
    Friend WithEvents Label3 As System.Windows.Forms.Label
    Friend WithEvents ErrorProvider1 As System.Windows.Forms.ErrorProvider

End Class