C ++字节数组到bitmapimage [英] c++ byte array to bitmapimage

问题描述

这是我关于stackoverflow的第一个问题。
我是UWP编程的新手，由于某种原因，我需要用C ++进行。现在，我正在尝试解决此问题：
我有一个字节数组的图像，想要在UI中显示它们。以下代码是我尝试过的代码，但是似乎无效。
这是C ++代码：

This is my first question on stackoverflow. I'm new to UWP programming, and due to some reason I need to do it in C++. Now I'm trying to solve this problem: I've got a byte array of images and want to show them in the UI. The following code is what I've tried but seems don't work. Here is C++ code:

BYTE input[160000] = ...;
InMemoryRandomAccessStream ^stream = ref new InMemoryRandomAccessStream();
DataWriter ^writer = ref new DataWriter();
writer->WriteBytes(Platform::ArrayReference<BYTE>(input, sizeof(input)));
stream->WriteAsync(writer->DetachBuffer());
stream->Seek(0);
BitmapImage ^image = ref new BitmapImage();
image->SetSourceAsync(stream);
outputPic->Source = image;

这是xaml代码：

<Image x:Name="outputPic" Source="Assets/Gray.png" Width="420" Stretch="Uniform" Height="420"/>

推荐答案

下面是一个示例：

MainPage.xaml（摘录）

<Image x:Name="image"/>

MainPage.xaml.cpp（摘录）

#include <fstream>
#include <vector>
#include <iterator>

MainPage::MainPage()
{
    InitializeComponent();

    std::ifstream input("Assets\\StoreLogo.png", std::ios::binary);
    std::vector<char> data((std::istreambuf_iterator<char>(input)), (std::istreambuf_iterator<char>()));

    // I just obtained a pointer to the image data through data.data()

    auto bitmapImage = ref new BitmapImage();
    image->Source = bitmapImage;

    auto stream = ref new InMemoryRandomAccessStream();
    auto writer = ref new DataWriter(stream->GetOutputStreamAt(0));

    writer->WriteBytes(ArrayReference<unsigned char>((unsigned char*)data.data(), data.size()));

    create_task(writer->StoreAsync()).then([=](unsigned bytesStored)
    {
        return bitmapImage->SetSourceAsync(stream);
    });
}

这篇关于C ++字节数组到bitmapimage的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！