从URL同步下载图像 [英] Synchronously download an image from URL

问题描述

我只想从互联网URL获取BitmapImage，但是我的函数没有似乎工作正常，只能让我看到一小部分形象。我知道WebResponse正在工作异步，这当然是为什么我有这个问题，但是如何同步执行？

这是我的功能：

 内部静态BitmapImage GetImageFromUrl（string url）
 {
 Uri urlUri = new Uri（url）; 
 WebRequest webRequest = WebRequest.CreateDefault（urlUri）; 
 webRequest.ContentType =image / jpeg; 
 WebResponse webResponse = webRequest.GetResponse（）; 
 
 BitmapImage image = new BitmapImage（）; 
 image.BeginInit（）; 
 image.StreamSource = webResponse.GetResponseStream（）; 
 image.EndInit（）; 
 
返回图片; 
} 
  

非常感谢您的帮助。

解决方案

首先，你应该只是下载图像，并将其存储在临时文件或 MemoryStream 中。然后从中创建 BitmapImage 对象。

您可以下载图像，例如：

  Uri urlUri = new Uri（url）; 
 var request = WebRequest.CreateDefault（urlUri）; 
 
 byte [] buffer = new byte [4096]; 
 
使用（var target = new FileStream（targetFileName，FileMode.Create，FileAccess.Write））
 {
 using（var response = request.GetResponse（））
 {
 using（var stream = response.GetResponseStream（））
 {
 int read; 
 
 while（（read = stream.Read（buffer，0，buffer.Length））> 0）
 {
 target.Write（buffer，0，read）; 
} 
} 
} 
} 
  

I am trying to do a simple thing but I can't ...

I just want to get a BitmapImage from a internet URL, but my function doesn't seem to work properly, it only return me a small part of the image. I know WebResponse are working async and that's certainly why I have this problem, but how can I do it synchronously ?

Here is my function :

    internal static BitmapImage GetImageFromUrl(string url)
    {
        Uri urlUri = new Uri(url);
        WebRequest webRequest = WebRequest.CreateDefault(urlUri);
        webRequest.ContentType = "image/jpeg";
        WebResponse webResponse = webRequest.GetResponse();

        BitmapImage image = new BitmapImage();
        image.BeginInit();
        image.StreamSource = webResponse.GetResponseStream();
        image.EndInit();

        return image;
    }

Thank a lot for your help.

解决方案

First you should just download the image, and store it locally in a temporary file or in a MemoryStream. And then create the BitmapImage object from it.

You can download the image for example like this:

Uri urlUri = new Uri(url); 
var request = WebRequest.CreateDefault(urlUri);

byte[] buffer = new byte[4096];

using (var target = new FileStream(targetFileName, FileMode.Create, FileAccess.Write))
{
    using (var response = request.GetResponse())
    {    
        using (var stream = response.GetResponseStream())
        {
            int read;

            while ((read = stream.Read(buffer, 0, buffer.Length)) > 0)
            {
                target.Write(buffer, 0, read);
            }
        }
    }
}

这篇关于从URL同步下载图像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！