Question

VB中 Image或PictureBox 显示网络图片问题

VB中 Image或PictureBox 显示网络图片

Private Declare Function OleLoadPicturePath Lib "oleaut32.dll" (ByVal szURLorPath As Long, ByVal punkCaller As Long, ByVal dwReserved As Long, ByVal clrReserved As OLE_COLOR, ByRef riid As TGUID, ByRef ppvRet As IPicture) As Long

Private Type TGUID
Data1 As Long
Data2 As Integer
Data3 As Integer
Data4(0 To 7) As Byte
End Type

'加载函数
Public Function LoadPicture(ByVal strFileName As String) As Picture
Dim IID As TGUID
With IID
.Data1 = &H7BF80980
.Data2 = &HBF32
.Data3 = &H101A
.Data4(0) = &H8B
.Data4(1) = &HBB
.Data4(2) = &H0
.Data4(3) = &HAA
.Data4(4) = &H0
.Data4(5) = &H30
.Data4(6) = &HC
.Data4(7) = &HAB
End With

On Error GoTo LocalErr

OleLoadPicturePath StrPtr(strFileName), 0&, 0&, 0&, IID, LoadPicture
Exit Function
LocalErr:
Set LoadPicture = VB.LoadPicture(strFileName)
Err.Clear
End Function

Private Sub Command1_Click()

Set Image1.Picture = LoadPicture("http://img.baidu.com/img/logo-zhidao.gif")
End Sub

这里的代码是可以的，但是有时候加载得慢会让程序定住，不能进行任何操作，要加载完毕才能继续操作。

好象DoEvents这个不行哦。。
有什么方法可以在加载的同时，也可以进行其他操作呢？？

请教~~请教~~
还是会卡着的哦，还有其他方法么？

Answer 1

Private Declare Function OleLoadPicturePath Lib "oleaut32.dll" (ByVal szURLorPath As Long, ByVal punkCaller As Long, ByVal dwReserved As Long, ByVal clrReserved As OLE_COLOR, ByRef riid As TGUID, ByRef ppvRet As IPicture) As Long

Private Type TGUID
Data1 As Long
Data2 As Integer
Data3 As Integer
Data4(0 To 7) As Byte
End Type

'加载函数
Public Function LoadPicture(ByVal strFileName As String) As Picture
Dim IID As TGUID
With IID
.Data1 = &H7BF80980
.Data2 = &HBF32
.Data3 = &H101A
.Data4(0) = &H8B
.Data4(1) = &HBB
.Data4(2) = &H0
.Data4(3) = &HAA
.Data4(4) = &H0
.Data4(5) = &H30
.Data4(6) = &HC
.Data4(7) = &HAB
DoEvents
End With

On Error GoTo LocalErr

OleLoadPicturePath StrPtr(strFileName), 0&, 0&, 0&, IID, LoadPicture
Exit Function
LocalErr:
Set LoadPicture = VB.LoadPicture(strFileName)
Err.Clear
End Function

Private Sub Command1_Click()
Set Image1.Picture = LoadPicture("https://gss0.bdstatic.com/70cFsjip0QIZ8tyhnq/img/logo-zhidao.gif")
End Sub

我这里很快，不知道你加载的是什么图片。。。

Answer 2

试试这个

Private Declare Function URLDownloadToFile Lib "urlmon" Alias "URLDownloadToFileA" (ByVal pCaller As Long, ByVal szURL As String, ByVal szFileName As String, ByVal dwReserved As Long, ByVal lpfnCB As Long) As Long

Private Sub Command1_Click()
LoadPictureFromURL Image1, "http://blog.txtbbs.com/attachments/2007/07/31347_200707232052203.jpg"
Image1.Refresh
End Sub

Sub LoadPictureFromURL(PicCtrl As Control, URL As String)
URLDownloadToFile 0&, URL, "c:\tmppp", 0&, 0&
Do Until Len(Dir("c:\tmppp"))
DoEvents
Loop
PicCtrl.Picture = LoadPicture("c:\tmppp")
Kill "c:\tmppp"
End Sub