【分享】vb过滤得到网页元素的通用函数

无·法 2017-01-17 09:12:46

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Option Explicit



Private Declare Function SafeArrayGetDim Lib "oleaut32.dll " (ByRef saArray() As Any) As Long



'名称：getElementsByAttributes

'功能：根据一个或多个条件对dom对象所有元素进行过滤得到目标元素

'参数：WebBrowser1，WebBrowser类型，要处理的webbrowser

'      strAttributes，string型，内容为属性列表，多项的话用逗号隔开，

'返回：如果有匹配到的结果那么返回的就是html元素对象数组，用户需要执行判断使用

'范例：getElementsByAttributes(WebBrowser1,"id='kw'")(0).value="vb" '设置百度搜索框内容为vb

'      getElementsByAttributes(WebBrowser1,"value='百度一下',type='submit'")(0).click '点击百度的搜索按钮

'      getElementsByAttributes(WebBrowser1,"tagname='input',value^='百度'")(0).click '得到文本开头为“百度”的按钮并执行点击

'      Dim v

'      For Each v In getElementsByAttributes(WebBrowser1, "tagname=img,src<>''")

'          Print v.src

'      Next



'作者：sysdzw

'日期：23:53 2017-1-17

Public Function getElementsByAttributes(WebBrowser1 As Object, ByVal strAttributes As String) As Variant

    Dim vTag As Object

    Dim i&, strTiaojians$, isElementOk As Boolean, intElement%, vrt()

    Dim reg As Object

    Dim matchs As Object

    Dim strAttrName As String, strAttrValue As String



    Set reg = CreateObject("vbscript.regExp")

    reg.Global = True

    reg.IgnoreCase = True

    reg.MultiLine = True

    reg.Pattern = "([a-z\dA-Z-_.]+)([!=<>^$*|~]+)(['""]?)([^,]*)\3"

    Set matchs = reg.Execute(strAttributes)



    For Each vTag In WebBrowser1.Document.All

        isElementOk = True

        For i = 0 To matchs.Count - 1 '循环判断strAttributes中的多个条件，只有都符合才能返回true，如果有一个不符合就返回false并且退出其他条件的判断

            strAttrName = LCase(matchs(i).SubMatches(0))

            If strAttrName = "classname" Then strAttrName = "class"

            If strAttrName = "tagname" Then

                If Not isConditionOk(LCase(vTag.tagname), matchs(i).SubMatches(1), LCase(matchs(i).SubMatches(3))) Then

                    isElementOk = False

                    Exit For

                End If

            ElseIf strAttrName = "innerhtml" Then

                If Not isConditionOk(LCase(vTag.innerhtml), matchs(i).SubMatches(1), LCase(matchs(i).SubMatches(3))) Then

                    isElementOk = False

                    Exit For

                End If

            ElseIf strAttrName = "innertext" Then

                If Not isConditionOk(LCase(vTag.innertext), matchs(i).SubMatches(1), LCase(matchs(i).SubMatches(3))) Then

                    isElementOk = False

                    Exit For

                End If

            ElseIf strAttrName = "class" Then

                strAttrValue = "NULL"

                If Not IsNull(vTag.getattribute("class")) Then

                    strAttrValue = vTag.getattribute("class")

                ElseIf Not IsNull(vTag.getattribute("classname")) Then

                    strAttrValue = vTag.getattribute("classname")

                End If

                If strAttrValue = "NULL" Then

                    isElementOk = False

                    Exit For

                ElseIf Not (isConditionOk(strAttrValue, matchs(i).SubMatches(1), LCase(matchs(i).SubMatches(3))) Or isConditionOk(strAttrValue, matchs(i).SubMatches(1), LCase(matchs(i).SubMatches(3)))) Then

                    isElementOk = False

                    Exit For

                End If

            ElseIf IsNull(vTag.getattribute(strAttrName)) Then

                isElementOk = False

                Exit For

            ElseIf Not isConditionOk(vTag.getattribute(strAttrName), matchs(i).SubMatches(1), matchs(i).SubMatches(3)) Then

                isElementOk = False

                Exit For

            End If

        Next



        If isElementOk Then

            ReDim Preserve vrt(intElement)

            Set vrt(intElement) = vTag

            intElement = intElement + 1

        End If

    Next

    If SafeArrayGetDim(vrt) = 0 Then

        getElementsByAttributes = Split("", "")

    Else

        getElementsByAttributes = vrt

    End If

End Function

'简略的调用方式

Public Function g(WebBrowser1 As Object, ByVal strAttributes As String) As Variant

    g = getElementsByAttributes(WebBrowser1, strAttributes)

End Function

'根据运算符检查条件是否符合

Private Function isConditionOk(ByVal strTagValue$, ByVal strCondition$, ByVal strValueForCheck$) As Boolean

    If strCondition = "=" Then

        isConditionOk = (strTagValue = strValueForCheck)

    ElseIf strCondition = "!=" Or strCondition = "<>" Then

        isConditionOk = (strTagValue <> strValueForCheck)

    ElseIf strCondition = "^=" Then '选取开头为strValueForCheck的

        isConditionOk = (Left(strTagValue, Len(strValueForCheck)) = strValueForCheck)

    ElseIf strCondition = "$=" Then '选取末尾为strValueForCheck的

        isConditionOk = (Right(strTagValue, Len(strValueForCheck)) = strValueForCheck)

    ElseIf strCondition = "*=" Then '选取包含strValueForCheck的

        isConditionOk = (InStr(strTagValue, strValueForCheck) > 0)

    ElseIf strCondition = "|=" Then '选取值为strValueForCheck或者值为strValueForCheck前缀的，即strValueForCheck后面加个-

        isConditionOk = (InStr(strTagValue, strValueForCheck) > 0 Or InStr(strTagValue, strValueForCheck & "-") > 0)

    ElseIf strCondition = "~=" Then '选取属性值用空格分隔的值中包含给定值的元素

        isConditionOk = (InStr(" " & strTagValue & " ", " " & strValueForCheck & " ") > 0)

    End If

End Function

使用范例，获取所有src属性不为空的元素并打印出来

Private Sub Command1_Click()

    Dim v

    For Each v In getElementsByAttributes(WebBrowser1, "tagname=img,src<>''")

        Print v.src

    Next

End Sub

条件可以组合，比如得到input按钮上名字为搜索的按钮对象，并且name不为search那么strAttributes条件就用"tagname='input',value='搜索',name!='search'"

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无·法 2019-05-13

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引用 30 楼 weixin_40174192 的回复:

可以再举个详细一点的使用方法吗，有点不太懂，例如要拿到a标签，并且class="bcd"的内容怎么办

Private Sub Command1_Click()

    Dim v

    For Each v In getElementsByAttributes(WebBrowser1, "tagname=a,class=bcd")

        Print v.href

    Next

End Sub