BitmapSource copyPixels正确的参数

Question

我使用stride会产生异常。输入图像为32位JPG格式。请告诉我我应该放入什么值(我尝试了很多东西，但它们在哪里产生异常或损坏的JPG)：

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array<System::Byte>^ pixels = gcnew array<System::Byte>(WHAT VALUE);        
bitmapSource->CopyPixels(pixels, WHAT VALUE, 0);

// Jpg.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <iostream>
#using <mscorlib.dll> //requires CLI
using namespace System;
using namespace System::IO;
using namespace System::Windows::Media::Imaging;
using namespace System::Windows::Media;
using namespace System::Windows::Controls;
using namespace std;

[System::STAThread]
int _tmain(int argc, _TCHAR* argv[])
{
    // Open a Stream and decode a JPEG image
    Stream^ imageStreamSource = gcnew FileStream("C:/heart2.jpg",
        FileMode::Open, FileAccess::Read, FileShare::Read);

    JpegBitmapDecoder^ decoder = gcnew JpegBitmapDecoder(
        imageStreamSource, BitmapCreateOptions::PreservePixelFormat,
        BitmapCacheOption::Default);
    BitmapSource^ bitmapSource = decoder->Frames[0];//< --mamy bitmape
    // Draw the Image
    Image^ myImage = gcnew Image();

    myImage->Source = bitmapSource;
    myImage->Stretch = Stretch::None;
    myImage->Margin = System::Windows::Thickness(20);

    int width = bitmapSource->PixelWidth;
    int height = bitmapSource->PixelHeight;
    int stride = (width * bitmapSource->Format.BitsPerPixel + 31) / 32;
    array<System::Byte>^ pixels
        = gcnew array<System::Byte>(height * width * stride);
    bitmapSource->CopyPixels(pixels, stride, 0);

    int x;
    cin >> x;
    return 0;
}

Answer 1

谷歌

http://msdn.microsoft.com/en-us/library/system.drawing.imaging.bitmapdata.stride.aspx

步幅是单行像素(扫描线)的宽度，向上舍入为四个字节的边界。

因此，正确的值取决于图像中每个像素的位数。