将VC的代码转换为Delphi。不够再加

Question

EdsError downloadEvfData(HDC hdc){    EdsStreamRef stream; // JPEG stream.
    EdsUInt32 zoom;
    EdsPoint zoomPosition;
    EdsPoint imagePosition;
    EdsUInt32 histogram[256 * 4]; //(YRGB) YRGBYRGBYRGBYRGB....
    
    EdsError err = EDS_ERR_OK;
    EdsEvfImageRef evfImage = NULL;
    EdsUInt32 bufferSize = 2 * 1024 * 1024;
    // Create memory stream.
    err = EdsCreateMemoryStream(bufferSize, &stream);    // Create EvfImageRef.
    if(err == EDS_ERR_OK)
    {
    err = EdsCreateEvfImageRef(stream, &evfImage);
    }    // Download live view image data.
    if(err == EDS_ERR_OK)
    {
    err = EdsDownloadEvfImage(camera, evfImage);    
    }
    
    // Get the incidental data of the image.
    if(err == EDS_ERR_OK)
    {
    // Get the zoom ratio
    EdsGetPropertyData(evfImage, kEdsPropID_Evf_ZoomPosition, 0 , sizeof(zoom), &zoom);
    // Get the focus and zoom border position
    EdsGetPropertyData(evfImage, kEdsPropID_Evf_ZoomPosition, 0 , sizeof(zoomPosition), &zoomPosition);
    // Get position of image data. (when enlarging)
    EdsGetPropertyData(evfImage, kEdsPropID_Evf_ImagePosition, 0, sizeof(imagePosition), &imagePosition);
    // Get histogram (RGBY).
    EdsGetPropertyData(evfImage, kEdsPropID_Evf_Histogram, 0, sizeof(histogram), &histogram);
    }
    //
    // Display image+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
    //
    Need to display the image in stream here
    //
    //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
    // Release stream
    if(stream != NULL)
    {
    EdsRelease(stream);
    stream = NULL;
    }
    // Release evfImage
    if(evfImage != NULL)
    {
    EdsRelease(evfImage);
    evfImage = NULL;
    }return err;
}To display the stream as a live image i have written following functions and called them as
/*
    LPPICTURE pic= getImageFromStream(hdc, dataSet);
        if(pic!=NULL){
        displayLiveCannon(hdc, pic);        drawForcusRectangle(pDC, CPoint(dataSet.zoomPosition.x, dataSet.zoomPosition.y));        }
*/LPPICTURE getImageFromStream(HDC hdc, EVF_DATASET dataSet){    EdsUInt32 size;
    LPPICTURE pic=NULL;    unsigned char* pbyteImage = NULL;     // Get image (JPEG) pointer.
    EdsGetPointer(dataSet.stream, (EdsVoid**)&pbyteImage );
    
    if(pbyteImage != NULL)
    {    EdsGetLength(dataSet.stream, &size);    LPSTREAM stream=NULL;    HGLOBAL hMem= ::GlobalAlloc(GMEM_FIXED, size);
    LPVOID pBuff= ::GlobalLock(hMem);    memcpy(pBuff, pbyteImage, size);    ::GlobalUnlock(hMem);
    CreateStreamOnHGlobal(hMem, TRUE, &stream);
    :leLoadPicture(stream,size,true,IID_IPicture,(LPVOID *)&pic);        //generates a huge memory wastage here    GlobalFree(hMem);
    }return pic;
}
void displayLiveCannon(HDC hdc, LPPICTURE pic){        long hmWidth, hmHeight;
        pic->get_Width(&hmWidth);
        pic->get_Height(&hmHeight);        int nWidth=MulDiv(hmWidth, GetDeviceCaps(hdc, LOGPIXELSX), 2540);
        int nHeight = MulDiv(hmHeight, GetDeviceCaps(hdc, LOGPIXELSY), 2540);
    
        pic->Render(hdc                //Handle of device context on which to render the image
                    , 0        //Horizontal position of image in hdc
                    , 0        //Vertical position of image in hdc
                    , nWidth    //Horizontal dimension of destination rectangle
                    , nHeight    //Vertical dimension of destination rectangle
                    , 0        //Horizontal offset in source picture
                    , hmHeight    //Vertical offset in source picture
                    , hmWidth    //Amount to copy horizontally in source picture
                    , -hmHeight    //Amount to copy vertically in source picture
                    , NULL);    //Pointer to position of destination for a metafile hdc}

Answer 1

关键是err = EdsCreateMemoryStream(bufferSize, &stream)
中的&符号不知道在DELPHI中如何表示

Answer 2

&在C++里可以表示引用和地址 
引用的时候对应VAR
表示地址的时候对应@

Answer 3

按你代码表面翻译了一下。可能不一定好用。
function downloadEvfData(hdc:HDC):EdsError;
var
    stream:EdsStreamRef;
    zoom:EdsUInt32;
    zoomPosition,imagePosition:EdsPoint;
    histogram:array[0..256*4] of EdsUInt32;
    err:EdsError;
    evfImage:EdsEvfImageRef;
    bufferSize:EdsUInt32;
begin
    err:=EDS_ERR_OK;
    evfImage:=nil;
    buffersize:=2*1024*1024;
    err:=EdsCreateMemoryStream(bufferSize,@stream);
    if err=EDS_ERR_OK then
        err:=EdsCreateEvfImageRef(stream, @evfImage);
    if err=EDS_ERR_OK then
        err:= EdsDownloadEvfImage(camera, evfImage);
    if err=EDS_ERR_OK then
    begin
        EdsGetPropertyData(evfImage, kEdsPropID_Evf_ZoomPosition, 0 , sizeof(zoom), @zoom);
        EdsGetPropertyData(evfImage, kEdsPropID_Evf_ZoomPosition, 0 , sizeof(zoomPosition), @zoomPosition);
        EdsGetPropertyData(evfImage, kEdsPropID_Evf_ImagePosition, 0, sizeof(imagePosition), @imagePosition);
        EdsGetPropertyData(evfImage, kEdsPropID_Evf_Histogram, 0, sizeof(histogram), @histogram);
    end;
    if stream<>nil then
    begin
        EdsRelease(stream);
        stream:=nil;
    end;
    if evfImage<>nil then
    begin
        EdsRelease(evfImage);
        evfImage:=nil;
    end;
    Result:=err;
end;function getImageFromStream(hdc:HDC;dataset:EVF_DATASET):LPPICTURE;
var
    size:EdsUInt32;
    pic:LPPICTURE;
    pbyteImage:PByte;
    stream:LPSTREAM;
    hMem:HGLOBAL;
    pBuff:LPVOID;
begin
    pic:=nil;
    pbyteImage:=nil;
    EdsGetPointer(dataSet.stream,EdsVoid(@pbyteImage));
    if pbyteImage<>nil then
    begin
        EdsGetLength(dataSet.stream, @size);
        stream:=nil;
        hMem:=GlobalAlloc(GMEM_FIXED, size);
        pBuff:=GlobalLock(hMem);
        copyMemory(pBuff,pbyteImage,size);
        GlobalUnlock(hMem);
        CreateStreamOnHGlobal(hMem, TRUE, @stream);
        leLoadPicture(stream,size,true,IID_IPicture,Pointer(pic));
        GlobalFree(hMem);
    end;
    Result:=pic;
end;procedure displayLiveCannon(hdc:HDC;pic:LPPICTURE);
var
    hmWidth, hmHeight:long;
    nWidth,nHeight:integer;
begin
    pic^.get_Width(@hmWidth);
    pic^.get_Height(@hmHeight);
    nWidth:=MulDiv(hmWidth, GetDeviceCaps(hdc, LOGPIXELSX), 2540);
    nHeight:= MulDiv(hmHeight, GetDeviceCaps(hdc, LOGPIXELSY), 2540);
    pic^.Render(hdc,0,0,nWidth,nHeight,0,hmHeight,hmWidth,-hmHeight,nil);
end;

Answer 4

非常感谢
里边的err:=EdsCreateMemoryStream(bufferSize,@stream);编译错误
具体定义如下：
    stream:EdsStreamRef;
    zoom:EdsUInt32;
    zoomPosition,imagePosition:EdsPoint;
    evfImage:EdsEvfImageRef;
    bufferSize:EdsUInt32;定义1
  EdsObject = Pointer;
  EdsBaseRef = EdsObject;               // Baseic refernce
  EdsStreamRef        = EdsBaseRef;     // Reference to a stream
  EdsImageRef         = EdsStreamRef;   // Reference to a image
  EdsEvfImageRef      = EdsBaseRef;   // Reference to a image
定义2
   EdsUInt32 = Cardinal;
定义3
  type EdsPoint = record
    x : EdsInt32;
    y : EdsInt32;
  end;
  PEdsPoint = ^EdsPoint;

Answer 5

其实就是C＋＋中&转delphi中相对应的符号

Answer 6

err:=EdsCreateMemoryStream(bufferSize,stream);

Answer 7

感谢 gzmhero
EdsGetPropertyData(evfImage, kEdsPropID_Evf_ZoomPosition, 0 , sizeof(zoomPosition), @zoomPosition);
这个好像用同样的方法不行
该怎么写呢

Answer 8

不知道EdsGetPropertyData定义是怎样的。
这样使用应该可以，其他调用的也都这样处理。EdsGetPropertyData(evfImage, kEdsPropID_Evf_ZoomPosition, 0 , sizeof(zoomPosition), Pointer(@zoomPosition)); 

Answer 9

这样定义
{ -----------------------------------------------------------------------------
  Function : EdsGetPropertyData  Description:
        Gets property information from the object designated in inRef.   Parameters:
       In: inRef            - The reference of the item.
           inPropertyID     - The ProprtyID
           inParam          - Additional information of property.
                              We use this parameter in order to specify an index
                              in case there are two or more values over the same ID.
            inPropertySize  - The number of bytes of the prepared buffer
                              for receive property-value.
       Out: outPropertyData - The buffer pointer to receive property-value.  Returns:
        Returns EDS_ERR_OK if successful. In other cases, see EDSDKError.pas.
----------------------------------------------------------------------------- }
function EdsGetPropertyData( inRef : EdsBaseRef;
                             inPropertyID : EdsPropertyID;
                             inParam : EdsInt32;
                             inPropertySize : EdsUInt32;
//                             var outPropertyData : EdsUInt32 ) : EdsError ; stdcall; external edsdk;
                             var outPropertyData : Pointer ) : EdsError ; stdcall; external edsdk;

Answer 10

这个是你自己定义的函数吧你问关键的,我回答关键,对&在Delphi中,定义时,使用var 参数调用时,在变量前加@

Answer 11

在Delphi中,定义为var的 参数 ,调用的时候在变量前不需要加@。

Answer 12

&参数，其时就是引用调用

Answer 13

想问一下，
typedef struct __EdsObject*    EdsBaseRef;
中结构体类型__EdsObject的定义是什么，想将这个转到delphi下，不知道它的具体定义，搜也搜不到，弄不下去了，还请各位大牛帮忙呀！

Answer 14

试过6楼的方法，将其定义为__EdsObject = Pointer;编译没有问题，但是得不到正确的结果

Answer 15

&c里表示取地址，用在函数参数中表示变量传进去后值是可改变的，该符号对应delphi是@
用在函数参数中，delphi的var就可以，var表示函数变量可改变输出，

Answer 16

挖坟贴，我手上有单反系列和G系列，爱国者系列的相机SDK，delphi语言
支持智能识别和连接相机....