Question

VB GDI+的问题

对GDI+不是很了解,下面这代码,按钮多按几次,图片就显示不出来了,谁能改改?
Private Type GdiplusStartupInput
GdiplusVersion As Long
DebugEventCallback As Long
SuppressBackgroundThread As Long
SuppressExternalCodecs As Long
End Type

Private Enum GpStatus 'Status
Ok = 0
GenericError = 1
InvalidParameter = 2
OutOfMemory = 3
ObjectBusy = 4
InsufficientBuffer = 5
NotImplemented = 6
Win32Error = 7
WrongState = 8
Aborted = 9
FileNotFound = 10
ValueOverflow = 11
AccessDenied = 12
UnknownImageFormat = 13
FontFamilyNotFound = 14
FontStyleNotFound = 15
NotTrueTypeFont = 16
UnsupportedGdiplusVersion = 17
GdiplusNotInitialized = 18
PropertyNotFound = 19
PropertyNotSupported = 20
End Enum

Private Declare Function GdiplusStartup Lib "gdiplus" (token As Long, inputbuf As GdiplusStartupInput, Optional ByVal outputbuf As Long = 0) As GpStatus
Private Declare Function GdiplusShutdown Lib "gdiplus" (ByVal token As Long) As GpStatus
Private Declare Function GdipDrawImageRect Lib "gdiplus" (ByVal graphics As Long, ByVal Image As Long, ByVal X As Single, ByVal Y As Single, ByVal Width As Single, ByVal Height As Single) As GpStatus
Private Declare Function GdipCreateFromHDC Lib "gdiplus" (ByVal hDC As Long, graphics As Long) As GpStatus
Private Declare Function GdipDeleteGraphics Lib "gdiplus" (ByVal graphics As Long) As GpStatus
Private Declare Function GdipLoadImageFromFile Lib "gdiplus" (ByVal filename As String, Image As Long) As GpStatus
Private Declare Function GdipDisposeImage Lib "gdiplus" (ByVal Image As Long) As GpStatus

Dim gdip_Token As Long
Dim gdip_Image As Long
Dim gdip_Graphics As Long
Dim i As Integer

'-------------缩略图函数-----------
Public Sub ShowTNImg(PBox As Object, ImagePath As String, WidthMax As Long, HeightMax As Long)
LoadGDIP
If GdipCreateFromHDC(PBox.hDC, gdip_Graphics) <> 0 Then
MsgBox "出现错误！", vbCritical, "错误"
GdiplusShutdown gdip_Token
End
End If

'载入图片到内存中
GdipLoadImageFromFile StrConv(ImagePath, vbUnicode), gdip_Image

'使用GDI+直接从内存中缩略并绘图，GDI+有很好的反锯齿能力
If GdipDrawImageRect(gdip_Graphics, gdip_Image, 0, 0, WidthMax, HeightMax) <> Ok Then Debug.Print "显示失败"

DisposeGDIP
End Sub

Public Sub LoadGDIP()
Dim GpInput As GdiplusStartupInput
GpInput.GdiplusVersion = 1
If GdiplusStartup(gdip_Token, GpInput) <> 0 Then
MsgBox "加载GDI+失败！", vbCritical, "加载错误"
End
End If
End Sub

Public Sub DisposeGDIP()
GdipDisposeImage gdip_Image
GdipDeleteGraphics gdip_Graphics
GdiplusShutdown gdip_Token
End Sub
太长了,还有:

Private Sub Command1_Click()
i = i + 1
Picture1.Picture = LoadPicture("")
Call ShowTNImg(Picture1, "F:\1\" & i & ".jpg", Picture1.Width / 15, Picture1.Height / 15)
'Label1.Caption = i
End Sub

Private Sub Form_Load()
i = 0
End Sub

用别的电脑试了下,还真是....
我再找别人试下= =
破电脑,问题真多

Answer 1

没问题呀，我一口气按了50次都正常显示。