ErrorProvider 类
提供用于指示窗体上的控件具有关联错误的用户界面。
**命名空间:**System.Windows.Forms
**程序集:**System.Windows.Forms（在 system.windows.forms.dll 中）
语法
声明
Public Class ErrorProvider
Inherits Component
Implements IExtenderProvider, ISupportInitialize
用法
Dim instance As ErrorProvider
public class ErrorProvider : Component, IExtenderProvider, ISupportInitialize
public ref class ErrorProvider : public Component, IExtenderProvider, ISupportInitialize
public class ErrorProvider extends Component implements IExtenderProvider, ISupportInitialize
public class ErrorProvider extends Component implements IExtenderProvider, ISupportInitialize
备注
ErrorProvider 显示一个简单的界面，向最终用户指出窗体上的控件具有与它关联的错误。如果为控件指定了错误描述字符串，控件旁将会出现一个图标。此图标按 BlinkStyle 指定的方式、以 BlinkRate 指定的速率闪烁。当鼠标悬停在此图标上时，会出现显示错误描述字符串的工具提示。
通常情况下，结合数据绑定控件使用 ErrorProvider。当将 ErrorProvider 同数据绑定控件一起使用时，必须指定 ContainerControl，可以在构造函数中指定，也可以通过设置 ContainerControl 属性指定。
提示
ErrorProvider 组件不提供对具有辅助功能的客户端的内置支持。若要在使用此组件时使应用程序可访问，必须提供一种附加的可访问反馈机制。
示例
下面的代码示例演示使用 ErrorProvider 类来通知用户有数据输入错误。该示例创建了一个包含 TextBox 控件、NumericUpDown 控件和 ComboBox 控件的 Form，并为每个控件创建 ErrorProvider，这些控件验证各自的内容。该示例使用 BlinkRate 和 BlinkStyle 属性及 SetIconAlignment 和 SetIconPadding 方法来设置错误图标选项。在控件的 Validated 事件过程中是否使用适当的错误文本调用 SetError 方法，取决于控件的内容。
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.favoriteColorComboBox, ErrorIconAlignment.MiddleRight)
favoriteColorErrorProvider.SetIconPadding(Me.favoriteColorComboBox, 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
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.favoriteColorComboBox, ErrorIconAlignment.MiddleRight);
favoriteColorErrorProvider.SetIconPadding (this.favoriteColorComboBox, 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")));
}
}
}
#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 ref 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 = gcnew System::Windows::Forms::TextBox;
this->label1 = gcnew System::Windows::Forms::Label;
this->label2 = gcnew System::Windows::Forms::Label;
this->ageUpDownPicker = gcnew System::Windows::Forms::NumericUpDown;
this->favoriteColorComboBox = gcnew System::Windows::Forms::ComboBox;
this->label3 = gcnew System::Windows::Forms::Label;
this->label4 = gcnew System::Windows::Forms::Label;
this->label5 = gcnew System::Windows::Forms::Label;
this->label6 = gcnew 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 = "Name:";
// Age Label
this->label2->Location = System::Drawing::Point( 40, 64 );
this->label2->Size = System::Drawing::Size( 56, 23 );
this->label2->Text = "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 = "Favorite color";
// ErrorBlinkStyle::AlwaysBlink Label
this->label4->Location = System::Drawing::Point( 264, 32 );
this->label4->Size = System::Drawing::Size( 160, 23 );
this->label4->Text = "ErrorBlinkStyle::AlwaysBlink";
// ErrorBlinkStyle::BlinkIfDifferentError Label
this->label5->Location = System::Drawing::Point( 264, 64 );
this->label5->Size = System::Drawing::Size( 200, 23 );
this->label5->Text = "ErrorBlinkStyle::BlinkIfDifferentError";
// ErrorBlinkStyle::NeverBlink Label
this->label6->Location = System::Drawing::Point( 264, 96 );
this->label6->Size = System::Drawing::Size( 200, 23 );
this->label6->Text = "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 += gcnew System::EventHandler( this, &Form1::nameTextBox1_Validated );
// Age NumericUpDown
this->ageUpDownPicker->Location = System::Drawing::Point( 112, 64 );
array<int>^temp0 = {150,0,0,0};
this->ageUpDownPicker->Maximum = System::Decimal( temp0 );
this->ageUpDownPicker->TabIndex = 4;
this->ageUpDownPicker->Validated += gcnew System::EventHandler( this, &Form1::ageUpDownPicker_Validated );
// Favorite Color ComboBox
array<Object^>^temp1 = {"None","Red","Yellow","Green","Blue","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 += gcnew 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 );
array<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 = "Error Provider Example";
// Create and set the ErrorProvider for each data entry control.
nameErrorProvider = gcnew 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 = gcnew System::Windows::Forms::ErrorProvider;
ageErrorProvider->SetIconAlignment( this->ageUpDownPicker, ErrorIconAlignment::MiddleRight );
ageErrorProvider->SetIconPadding( this->ageUpDownPicker, 2 );
ageErrorProvider->BlinkStyle = System::Windows::Forms::ErrorBlinkStyle::BlinkIfDifferentError;
favoriteColorErrorProvider = gcnew System::Windows::Forms::ErrorProvider;
favoriteColorErrorProvider->SetIconAlignment( this->favoriteColorComboBox, ErrorIconAlignment::MiddleRight );
favoriteColorErrorProvider->SetIconPadding( this->favoriteColorComboBox, 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." );
}
}
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, "" );
}
}
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.
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( "None" )));
}
};
[STAThread]
int main()
{
Application::Run( gcnew Form1 );
}
package ErrorProvider;
import System.*;
import System.Drawing.*;
import System.Windows.Forms.*;
public class Form1 extends 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;
/** @attribute STAThread()
*/
public static void main(String[] args)
{
Application.Run(new Form1());
} //main
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.set_Location(new System.Drawing.Point(56, 32));
this.label1.set_Size(new System.Drawing.Size(40, 23));
this.label1.set_Text("Name:");
// Age Label
this.label2.set_Location(new System.Drawing.Point(40, 64));
this.label2.set_Size(new System.Drawing.Size(56, 23));
this.label2.set_Text("Age (3-5)");
// Favorite Color Label
this.label3.set_Location(new System.Drawing.Point(24, 96));
this.label3.set_Size(new System.Drawing.Size(80, 24));
this.label3.set_Text("Favorite color");
// ErrorBlinkStyle.AlwaysBlink Label
this.label4.set_Location(new System.Drawing.Point(264, 32));
this.label4.set_Size(new System.Drawing.Size(160, 23));
this.label4.set_Text("ErrorBlinkStyle.AlwaysBlink");
// ErrorBlinkStyle.BlinkIfDifferentError Label
this.label5.set_Location(new System.Drawing.Point(264, 64));
this.label5.set_Size(new System.Drawing.Size(200, 23));
this.label5.set_Text("ErrorBlinkStyle.BlinkIfDifferentError");
// ErrorBlinkStyle.NeverBlink Label
this.label6.set_Location(new System.Drawing.Point(264, 96));
this.label6.set_Size(new System.Drawing.Size(200, 23));
this.label6.set_Text("ErrorBlinkStyle.NeverBlink");
// Name TextBox
this.nameTextBox1.set_Location(new System.Drawing.Point(112, 32));
this.nameTextBox1.set_Size(new System.Drawing.Size(120, 20));
this.nameTextBox1.set_TabIndex(0);
this.nameTextBox1.add_Validated(new System.EventHandler(
this.nameTextBox1_Validated));
// Age NumericUpDown
this.ageUpDownPicker.set_Location(new System.Drawing.Point(112, 64));
this.ageUpDownPicker.set_Maximum(new System.Decimal(new int[] {
150, 0, 0, 0 }));
this.ageUpDownPicker.set_TabIndex(4);
this.ageUpDownPicker.add_Validated(new System.EventHandler(
this.ageUpDownPicker_Validated));
// Favorite Color ComboBox
this.favoriteColorComboBox.get_Items().AddRange(new Object[] {
"None", "Red", "Yellow", "Green", "Blue", "Purple" });
this.favoriteColorComboBox.set_Location(
new System.Drawing.Point(112, 96));
this.favoriteColorComboBox.set_Size(new System.Drawing.Size(120, 21));
this.favoriteColorComboBox.set_TabIndex(5);
this.favoriteColorComboBox.add_Validated(new System.EventHandler(
this.favoriteColorComboBox_Validated));
// Set up how the form should be displayed and add the controls to
// the form.
this.set_ClientSize(new System.Drawing.Size(464, 150));
this.get_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.set_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.set_BlinkRate(1000);
nameErrorProvider.set_BlinkStyle(
System.Windows.Forms.ErrorBlinkStyle.AlwaysBlink);
nameErrorProvider.set_ContainerControl(this);
ageErrorProvider = new System.Windows.Forms.ErrorProvider();
ageErrorProvider.SetIconAlignment(this.ageUpDownPicker,
ErrorIconAlignment.MiddleRight);
ageErrorProvider.SetIconPadding(this.ageUpDownPicker, 2);
ageErrorProvider.set_BlinkStyle(
System.Windows.Forms.ErrorBlinkStyle.BlinkIfDifferentError);
ageErrorProvider.set_ContainerControl(this);
favoriteColorErrorProvider = new System.Windows.Forms.ErrorProvider();
favoriteColorErrorProvider.SetIconAlignment(this.favoriteColorComboBox,
ErrorIconAlignment.MiddleRight);
favoriteColorErrorProvider.SetIconPadding(this.favoriteColorComboBox, 2);
favoriteColorErrorProvider.set_BlinkRate(1000);
favoriteColorErrorProvider.set_BlinkStyle(
System.Windows.Forms.ErrorBlinkStyle.NeverBlink);
favoriteColorErrorProvider.set_ContainerControl(this);
} //Form1
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.");
}
} //nameTextBox1_Validated
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, "");
}
}
} //ageUpDownPicker_Validated
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, "");
}
} //favoriteColorComboBox_Validated
// Functions to verify data.
private boolean IsNameValid()
{
// Determine whether the text box contains a zero-length string.
return ((nameTextBox1.get_Text().get_Length()) > 0);
} //IsNameValid
private boolean IsAgeTooYoung()
{
// Determine whether the age value is less than three.
return (System.Convert.ToInt32(ageUpDownPicker.get_Value()) < 3);
} //IsAgeTooYoung
private boolean IsAgeTooOld()
{
// Determine whether the age value is greater than five.
return (System.Convert.ToInt32(ageUpDownPicker.get_Value()) > 5);
} //IsAgeTooOld
private boolean IsColorValid()
{
// Determine whether the favorite color has a valid value.
return (favoriteColorComboBox.get_SelectedItem() != null)
&& (!(favoriteColorComboBox.get_SelectedItem().
ToString().Equals("None")));
} //IsColorValid
} //Form1
下面的代码示例演示如何使用带有 DataSource 和 DataMember 的 ErrorProvider 向用户指示数据错误。
Private Sub InitializeComponent()
' Standard control setup.
'....
' You set the DataSource to a data set, and the DataMember to a table.
errorProvider1.DataSource = dataSet1
errorProvider1.DataMember = dataTable1.TableName
errorProvider1.ContainerControl = Me
errorProvider1.BlinkRate = 200
End Sub 'InitializeComponent
'...
' Since the ErrorProvider control does not have a visible component,
' it does not need to be added to the form.
Private Sub buttonSave_Click(ByVal sender As Object, ByVal e As System.EventArgs)
' Checks for a bad post code.
Dim CustomersTable As DataTable
CustomersTable = customersDataSet1.Tables("Customers")
Dim row As DataRow
For Each row In CustomersTable.Rows
If Convert.ToBoolean(row("PostalCodeIsNull")) Then
row.RowError = "The Customer details contain errors"
row.SetColumnError("PostalCode", "Postal Code required")
End If
Next row
End Sub 'buttonSave_Click
private void InitializeComponent()
{
// Standard control setup.
//....
// You set the DataSource to a data set, and the DataMember to a table.
errorProvider1.DataSource = dataSet1 ;
errorProvider1.DataMember = dataTable1.TableName ;
errorProvider1.ContainerControl = this ;
errorProvider1.BlinkRate = 200 ;
//...
// Since the ErrorProvider control does not have a visible component,
// it does not need to be added to the form.
}
private void buttonSave_Click(object sender, System.EventArgs e)
{
// Checks for a bad post code.
DataTable CustomersTable;
CustomersTable = customersDataSet1.Tables["Customers"];
foreach (DataRow row in (CustomersTable.Rows))
{
if (Convert.ToBoolean(row["PostalCodeIsNull"]))
{
row.RowError="The Customer details contain errors";
row.SetColumnError("PostalCode", "Postal Code required");
}
}
}
private:
void InitializeComponent()
{
// Standard control setup.
//....
// You set the DataSource to a data set, and the DataMember to a table.
errorProvider1->DataSource = dataSet1;
errorProvider1->DataMember = dataTable1->TableName;
errorProvider1->ContainerControl = this;
errorProvider1->BlinkRate = 200;
//...
// Since the ErrorProvider control does not have a visible component,
// it does not need to be added to the form.
}
private:
void buttonSave_Click( Object^ /*sender*/, System::EventArgs^ /*e*/ )
{
// Checks for a bad post code.
DataTable^ CustomersTable;
CustomersTable = customersDataSet1->Tables[ "Customers" ];
System::Collections::IEnumerator^ myEnum = (CustomersTable->Rows)->GetEnumerator();
while ( myEnum->MoveNext() )
{
DataRow^ row = safe_cast<DataRow^>(myEnum->Current);
if ( Convert::ToBoolean( row[ "PostalCodeIsNull" ] ) )
{
row->RowError = "The Customer details contain errors";
row->SetColumnError( "PostalCode", "Postal Code required" );
}
}
}
private void InitializeComponent()
{
// Standard control setup.
//....
// You set the DataSource to a data set, and the DataMember
// to a table.
errorProvider1.set_DataSource(dataSet1);
errorProvider1.set_DataMember(dataTable1.get_TableName());
errorProvider1.set_ContainerControl(this);
errorProvider1.set_BlinkRate(200);
//...
// Since the ErrorProvider control does not have a visible component,
// it does not need to be added to the form.
} //InitializeComponent
protected void buttonSave_Click(Object sender, System.EventArgs e)
{
// Checks for a bad post code.
DataTable customersTable;
customersTable = customersDataSet1.get_Tables().get_Item("Customers");
for (int iCtr = 0; iCtr < customersTable.get_Rows().get_Count();
iCtr++) {
DataRow row = customersTable.get_Rows().get_Item(iCtr);
if (Convert.ToBoolean(row.get_Item("PostalCodeIsNull"))) {
row.set_RowError("The Customer details contain errors");
row.SetColumnError("PostalCode", "Postal Code required");
}
}
} //buttonSave_Click
继承层次结构
System.Object
System.MarshalByRefObject
System.ComponentModel.Component
System.Windows.Forms.ErrorProvider
线程安全
此类型的任何公共静态（Visual Basic 中的 Shared）成员都是线程安全的，但不保证所有实例成员都是线程安全的。
平台
Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Mobile for Smartphone、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition
.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。
版本信息
.NET Framework
受以下版本支持：2.0、1.1、1.0