Validating in vb net

Validating the information entered by users is an essential part of developing a professional Web-based user interface. NET validation controls use a combination of the benefits of traditional data validation. NET data validation controls process data validation on the Web server, but you can also optionally process data validation on the user's computer. Hence, if you configure the data validation controls to enable validation on the user's computer, the resulting HTML is browser-specific.

More precisely, the rendered HTML uses a script library called Web and implements Microsoft JScript functionality that is only supported by Microsoft Internet Explorer 4.0 and later versions.

Windows Formアプリケーションで入力チェックを行うには Validatingイベントを使用します。 例として、以下のような画面で考えてみます。 データ1(テキストボックス)に不正な値が含まれている場合に、ほかのコントロールにフォーカスを移動できないようにするには 1.データ1のValidatingイベント内で入力チェックをする 2.不正な値が含まれている場合は、Validatingイベントの引数 e.

Cancelに trueをセット を実施します。 Cause Vaidatingプロパティに false がセットされている場合は Validatingイベントは発生しないので注意が必要です。 データ1のText Boxで「.」を不正文字として扱う時のコード例は以下の通りです。 VBの例 -1 Then Message Box. Cancel = True End If End Sub '[キャンセル]ボタンのイベント Private Sub btn Cancel_Click(sender As Object, e As Event Args) Handles btn Cancel. Close() End Sub Text Boxコントロールのインベントは、ほかのコントロールへフォーカスが移動するとき以下の順でイベントが発生します。 コード例の中のコメントでも書いていますが、e.

He has been a featured speaker at many industry events including Microsoft Dev Days and the ASP. Shannon speaks and trains for companies such as App Dev ( and Learn It ( and has been a featured speaker in training videos with Learn Key. Data validation over the Web is performed in one of two locations: on the user's computer, or on the Web server.

NET and Web Services Solutions conference produced by PRO. He has also worked with large corporate clients including Microsoft, Universal Studios, MGM Studios, Monster.com/Flip Dog.com, Intel, Polygram Pictures, Prudential, Micro Accounting Systems, Sky Harbor International Airport, and Southern Automated Systems on projects using Microsoft technologies such as Visual Fox Pro, Visual Studio. Most applications perform their data validation on the user's local computer.

These address validation methods are more efficient than validating multiple addresses individually in a loop, mainly because they group addresses with the same domain and validate them in one pass, which speeds up the process and lowers the resource usage and the possibility of IP blacklisting. Dim addresses As New List(Of Mail Address)() From ' Validate address list and display results.

The following example shows how to verify a collection of email addresses. Dim results As IList(Of Mail Address Validation Result) = Mail Address Validator.

This increases performance and reduces traffic over the Web.

A slightly negative aspect of validating data on the user's computer is that the validation is performed via a script residing in the Web page. You only have two possible scripting languages that you can use on a user's computer: VBScript or Java Script.

Furthermore, the data validation scripts are protected inside the Web server so they are not vulnerable to malicious user modifications.

In its efforts to improve Web development on the whole, Microsoft included in ASP. NET validation controls), which offer an exceptional solution to data validation. NET comes with five validation controls as well as a summary control. NET Web application renders the data validation controls on the user's computer as HTML elements based upon the selected Target Schema property.

Some resources also refer to Jscript (Microsoft) and ECMAScript (European Computer Manufacturer's Association), but these are both derivatives of Java Script.

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