vb.net 教程 12-3 HtmlElement类 6

经过上面两节的学习，我们已经可以做到填充数据和提交表单了。

作为一个自动填表软件，自然需要同时完成以上两方面的功能。

简单的是我们可以直接将两段代码合并在一起：

    Private Sub btnOneKey1_Click(sender As Object, e As EventArgs) Handles btnOneKey1.Click        Dim strName As String = "张三"        Dim strAge As String = "12"        Dim htmlAlls As HtmlElementCollection        htmlAlls = wbMain.Document.All        For Each htmlSingle As HtmlElement In htmlAlls            Select Case htmlSingle.GetAttribute("name")                Case "studentname"                    htmlSingle.SetAttribute("value", strName)                Case "studentage"                    htmlSingle.SetAttribute("value", strAge)                Case Else                    '不处理            End Select        Next        For Each htmlSingle As HtmlElement In htmlAlls            Select Case htmlSingle.GetAttribute("name")                Case "submit1"                    htmlSingle.RaiseEvent("onclick")                Case Else                    '不处理            End Select        Next    End Sub

当然代码会遍历了网页内的所有元素，但实际上我们只需要Input标签的数据。

那么可以将

htmlAlls = wbMain.Document.All

修改为：

htmlAlls = wbMain.Document.GetElementsByTagName("Input")

完整代码：

    Private Sub btnOneKey2_Click(sender As Object, e As EventArgs) Handles btnOneKey2.Click        Dim strName As String = "李四"        Dim strAge As String = "21"        Dim htmlAlls As HtmlElementCollection        htmlAlls = wbMain.Document.GetElementsByTagName("Input")        For Each htmlSingle As HtmlElement In htmlAlls            Select Case htmlSingle.GetAttribute("name")                Case "studentname"                    htmlSingle.SetAttribute("value", strName)                Case "studentage"                    htmlSingle.SetAttribute("value", strAge)                Case Else                    '不处理            End Select        Next        For Each htmlSingle As HtmlElement In htmlAlls            Select Case htmlSingle.GetAttribute("name")                Case "submit1"                    htmlSingle.RaiseEvent("onclick")                Case Else                    '不处理            End Select        Next    End Sub

还是需要两次枚举，因为我们不能在数据没有填充完之前就提交。

那么，还可以采用一种指定对象的方法：HtmlDocument.GetElementById()，参数为网页元素的ID，通常这个是不重复的。

具体代码如下：

    Private Sub btnOneKey3_Click(sender As Object, e As EventArgs) Handles btnOneKey3.Click        Dim strName As String = "王五"        Dim strAge As String = "7"        Dim htmlName As HtmlElement        htmlName = wbMain.Document.GetElementById("studentname")        htmlName.SetAttribute("value", strName)        Dim htmlAge As HtmlElement        htmlAge = wbMain.Document.GetElementById("studentage")        htmlAge.SetAttribute("value", strAge)        Dim htmlSubmit As HtmlElement        htmlSubmit = wbMain.Document.GetElementById("submit1")        htmlSubmit.RaiseEvent("onclick")    End Sub

运行效果如下：

由于.net平台下C#和vb.NET很相似，本文也可以为C#爱好者提供参考。

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