不失真縮放圖片__VB

Option Explicit'Form1上添加1個圖片框picture1Private Declare Function StretchBlt Lib "gdi32" (ByVal hdc As Long, ByVal x As Long, ByVal y As Long, ByVal nWidth As Long, ByVal nHeight As Long, ByVal hSrcDC As Long, ByVal xSrc As Long, ByVal ySrc As Long, ByVal nSrcWidth As Long, ByVal nSrcHeight As Long, ByVal dwRop As Long) As LongPrivate Declare Function SetStretchBltMode Lib "gdi32" (ByVal hdc As Long, ByVal nStretchMode As Long) As LongPrivate Const HALFTONE = 4Private Const SRCCOPY = &HCC0020 ' (DWORD) dest = sourcePrivate Sub Form_Load()        Picture1.Picture = LoadPicture("C:\images.jpg") '這時加入背景圖,使其一運行就充滿表單        Picture1.Visible = False        Picture1.AutoRedraw = True        Me.AutoRedraw = True        Call Form_Resize        Me.Refresh        Me.AutoRedraw = FalseEnd SubPrivate Sub Form_Resize()        Dim Rtn As Long        Dim hDC1 As Long, hDC2 As Long        hDC1 = Picture1.hdc        hDC2 = Me.hdc        Call SetStretchBltMode(hDC2, HALFTONE)        Rtn = StretchBlt(hDC2, 0, 0, Me.ScaleWidth, Me.ScaleHeight, hDC1, 0, 0, Picture1.ScaleWidth, Picture1.ScaleHeight, SRCCOPY)        Me.AutoRedraw = True        Me.RefreshEnd Sub

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