[VB.NET]ErrorProvider

June 15, 2009

.csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, “Courier New”, courier, monospace; background-color: #ffffff; /white-space: pre;/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }]]> ErrorProvider的運用除了上面介紹的正規使用方式外。有時我們在撰寫介面時，我們會希望當介面上的資料有任意錯誤發生，則不讓使用者關閉、或是彈出確認視窗。通常一般的作法可能會透過Flag另外去記錄資訊，藉此判別是否有錯誤的資料。其實透過ErrorProvider我們可以很容易很方便的達到這需求。程式碼如下：Public Class Form1 Private Sub TextBox1_Validated(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox3.Validated, TextBox2.Validated, TextBox1.Validated Dim ctrl As Control = DirectCast(sender, Control) ErrorProvider1.SetError(ctrl, If(IsNumeric(ctrl.Text), "", “此欄位只接受數字”)) End Sub Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click If IsError() Then If MsgBox(“部分設定有誤”) = MsgBoxResult.Ok Then Return End If End If Me.Close() End Sub Private Function IsError() As Boolean For Each ctrl As Control In Controls If ErrorProvider1.GetError(ctrl).Length > 0 Then Return True End If Next Return False End FunctionEnd Class<![CDATA[

VB.NET