MessageBox 類別
定義
重要
部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。
顯示訊息視窗 (亦稱為對話方塊)，以顯示訊息給使用者。 它是強制回應視窗，除非使用者將它關閉，否則將無法在應用程式中執行其他動作。 MessageBox 可以包含文字、按鈕和通知與指示使用者的符號。
public ref class MessageBoxpublic class MessageBoxtype MessageBox = classPublic Class MessageBox- 繼承
-
MessageBox
範例
下列程式碼範例示範如何使用 MessageBox ，通知使用者在 中 TextBox 遺漏的專案。 這個範例需要從現有表單中呼叫 方法，並在其中具有 TextBox 具名 ServerName 。
private:
void validateUserEntry()
{
// Checks the value of the text.
if ( serverName->Text->Length == 0 )
{
// Initializes the variables to pass to the MessageBox::Show method.
String^ message = "You did not enter a server name. Cancel this operation?";
String^ caption = "No Server Name Specified";
MessageBoxButtons buttons = MessageBoxButtons::YesNo;
System::Windows::Forms::DialogResult result;
// Displays the MessageBox.
result = MessageBox::Show( this, message, caption, buttons );
if ( result == ::DialogResult::Yes )
{
// Closes the parent form.
this->Close();
}
}
}
private void validateUserEntry()
{
// Checks the value of the text.
if(serverName.Text.Length == 0)
{
// Initializes the variables to pass to the MessageBox.Show method.
string message = "You did not enter a server name. Cancel this operation?";
string caption = "Error Detected in Input";
MessageBoxButtons buttons = MessageBoxButtons.YesNo;
DialogResult result;
// Displays the MessageBox.
result = MessageBox.Show(message, caption, buttons);
if (result == System.Windows.Forms.DialogResult.Yes)
{
// Closes the parent form.
this.Close();
}
}
}
Private Sub ValidateUserEntry()
' Checks the value of the text.
If ServerName.Text.Length = 0 Then
' Initializes variables to pass to the MessageBox.Show method.
Dim Message As String = "You did not enter a server name. Cancel this operation?"
Dim Caption As String = "Error Detected in Input"
Dim Buttons As MessageBoxButtons = MessageBoxButtons.YesNo
Dim Result As DialogResult
'Displays the MessageBox
Result = MessageBox.Show(Message, Caption, Buttons)
' Gets the result of the MessageBox display.
If Result = System.Windows.Forms.DialogResult.Yes Then
' Closes the parent form.
Me.Close()
End If
End If
End Sub
下列程式碼範例示範如何詢問使用者是還是沒有問題，並根據回應做出決策。
private:
void Form1_FormClosing(Object^ sender, FormClosingEventArgs^ e)
{
// If the no button was pressed ...
if ((MessageBox::Show(
"Are you sure that you would like to close the form?",
"Form Closing", MessageBoxButtons::YesNo,
MessageBoxIcon::Question) == DialogResult::No))
{
// cancel the closure of the form.
e->Cancel = true;
}
}
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
const string message =
"Are you sure that you would like to close the form?";
const string caption = "Form Closing";
var result = MessageBox.Show(message, caption,
MessageBoxButtons.YesNo,
MessageBoxIcon.Question);
// If the no button was pressed ...
if (result == DialogResult.No)
{
// cancel the closure of the form.
e.Cancel = true;
}
}
Private Sub Form1_FormClosing( _
ByVal sender As System.Object, _
ByVal e As System.Windows.Forms.FormClosingEventArgs) _
Handles MyBase.FormClosing
Dim message As String = _
"Are you sure that you would like to close the form?"
Dim caption As String = "Form Closing"
Dim result = MessageBox.Show(message, caption, _
MessageBoxButtons.YesNo, _
MessageBoxIcon.Question)
' If the no button was pressed ...
If (result = DialogResult.No) Then
' cancel the closure of the form.
e.Cancel = True
End If
End Sub
備註
您無法建立 類別的新實例 MessageBox 。 若要顯示訊息方塊，請呼叫 static 方法 MessageBox.Show 。 訊息方塊中顯示的標題、訊息、按鈕和圖示是由您傳遞給此方法的參數所決定。