HttpListener如何提供图片 [英] HttpListener how to serve images
问题描述
我正在制作一个简单的网络服务器来提供html，css，js&图片(在C#中完成).我正在使用HttpListener，并且可以使html，javascript和css文件正常工作.我只是在图像上遇到麻烦.这是我目前正在使用的:
I'm making a simple webserver to serve html, css, js & images (done in c#). I am using HttpListener and I can get the html, javascript and css files to work properly. I am just having trouble with the images. This is what I'm using currently:
if (request.RawUrl.ToLower().Contains(".png") || request.RawUrl.Contains(".ico") || request.RawUrl.ToLower().Contains(".jpg") || request.RawUrl.ToLower().Contains(".jpeg"))
{
string dir = System.IO.Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location);
string[] img = request.RawUrl.Split('/');
string path = dir + @"\public\imgs\" + img[img.Length - 1];
FileInfo fileInfo = new FileInfo(path);
long numBytes = fileInfo.Length;
FileStream fileStream = new FileStream(path, FileMode.Open, FileAccess.Read);
BinaryReader binaryReader = new BinaryReader(fileStream);
byte[] output = binaryReader.ReadBytes((int)numBytes);
binaryReader.Close();
fileStream.Close();
var temp = System.Text.Encoding.UTF8.GetString(output);
return temp;
}
我正在将图像转换为字符串以返回它们(这是老板建议的方式).这是我处理这些请求的方法.
I am converting the image into a string to return them (it's the way my boss suggested). This is the method where I am handling these requests.
private static string SendResponse(HttpListenerRequest request)
这是我的WebServer类的Run()方法.对SetContentType的调用仅通过request.RawUrl并确定内容类型.
This is my WebServer classes Run() method. The call to SetContentType just goes through the request.RawUrl and determines the content type.
public void Run()
{
ThreadPool.QueueUserWorkItem((o) =>
{
Console.WriteLine("StackLight Web Server is running...");
try
{
while (_listener.IsListening)
{
ThreadPool.QueueUserWorkItem((c) =>
{
var ctx = c as HttpListenerContext;
try
{
// store html content in a byte array
string responderString = _responderMethod(ctx.Request);
// set the content type
ctx.Response.Headers[HttpResponseHeader.ContentType] = SetContentType(ctx.Request.RawUrl);
byte[] buffer = buffer = Encoding.UTF8.GetBytes(responderString);
// this writes the html out from the byte array
ctx.Response.ContentLength64 = buffer.Length;
using(Stream stream = ctx.Response.OutputStream)
{
stream.Write(buffer, 0, buffer.Length);
}
}
catch (Exception ex)
{
ConfigLogger.Instance.LogCritical(LogCategory, ex);
}
}, _listener.GetContext());
}
}
catch (Exception ex)
{
ConfigLogger.Instance.LogCritical(LogCategory, ex);
}
});
}
我的html页面需要在屏幕上显示图像，到目前为止，它显示的图像已损坏.我知道images目录是正确的，我对此进行了测试.
My html page needs to display an image to the screen, it displays a broken image so far. I know the images directory is correct, I tested that.
这是我获取网络服务器代码的地方:此处
This is where I got my code for the webserver: here
我在想，也许我必须更改SendResponse方法以不返回字符串
I was thinking that maybe I have to change the SendResponse method to not return a string
推荐答案
我知道了.我创建了一个类来保存数据，内容类型和request.RawUrl.然后，在传递字符串的地方，将其更改为传递我创建的对象.
I figured it out. I created a class to hold the data, content type and the request.RawUrl. Then, where I was passing a string, I changed it to pass the object I created.
因此，对于我的WebServer类，我的Run方法看起来像这样:
So, for my WebServer class, my Run method looks like this:
public void Run()
{
ThreadPool.QueueUserWorkItem((o) =>
{
Console.WriteLine("StackLight Web Server is running...");
try
{
while (_listener.IsListening)
{
ThreadPool.QueueUserWorkItem((c) =>
{
var ctx = c as HttpListenerContext;
try
{
// set the content type
ctx.Response.Headers[HttpResponseHeader.ContentType] = SetContentType(ctx.Request.RawUrl);
WebServerRequestData data = new WebServerRequestData();
// store html content in a byte array
data = _responderMethod(ctx.Request);
string res = "";
if(data.ContentType.Contains("text"))
{
char[] chars = new char[data.Content.Length/sizeof(char)];
System.Buffer.BlockCopy(data.Content, 0, chars, 0, data.Content.Length);
res = new string(chars);
data.Content = Encoding.UTF8.GetBytes(res);
}
// this writes the html out from the byte array
ctx.Response.ContentLength64 = data.Content.Length;
ctx.Response.OutputStream.Write(data.Content, 0, data.Content.Length);
}
catch (Exception ex)
{
ConfigLogger.Instance.LogCritical(LogCategory, ex);
}
finally
{
ctx.Response.OutputStream.Close();
}
}, _listener.GetContext());
}
}
catch (Exception ex)
{
ConfigLogger.Instance.LogCritical(LogCategory, ex);
}
});
}
我的SendResponse方法如下:
And my SendResponse method looks like this:
private static WebServerRequestData SendResponse(HttpListenerRequest request)
{
string dir = System.IO.Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location);
string[] fileUrl = request.RawUrl.Split('/');
// routes
if (request.RawUrl.Contains("/"))
{
// this is the main page ('/'), all other routes can be accessed from here (including css, js, & images)
if (request.RawUrl.ToLower().Contains(".png") || request.RawUrl.ToLower().Contains(".ico") || request.RawUrl.ToLower().Contains(".jpg") || request.RawUrl.ToLower().Contains(".jpeg"))
{
try
{
string path = dir + Properties.Settings.Default.ImagesPath + fileUrl[fileUrl.Length - 1];
FileInfo fileInfo = new FileInfo(path);
path = dir + @"\public\imgs\" + fileInfo.Name;
byte[] output = File.ReadAllBytes(path);
_data = new WebServerRequestData() {Content = output, ContentType = "image/png", RawUrl = request.RawUrl};
//var temp = System.Text.Encoding.UTF8.GetString(output);
//return Convert.ToBase64String(output);
return _data;
}
catch(Exception ex)
{
ConfigLogger.Instance.LogError(LogCategory, "File could not be read.");
ConfigLogger.Instance.LogCritical(LogCategory, ex);
_errorString = string.Format("<html><head><title>Test</title></head><body>There was an error processing your request:<br />{0}</body></html>", ex.Message);
_byteData = new byte[_errorString.Length * sizeof(char)];
System.Buffer.BlockCopy(_errorString.ToCharArray(), 0, _byteData, 0, _byteData.Length);
_data = new WebServerRequestData() { Content = _byteData, ContentType = "text/html", RawUrl = request.RawUrl };
return _data;
}
}
我仍在清理代码，但是现在可以处理图像了！
I'm still cleaning up the code a bit but it now serves the images!
哦...这是我正在使用的对象:
Oh... And here is the object I'm using:
public class WebServerRequestData
{
public string RawUrl { get; set; }
public string ContentType { get; set; }
public byte[] Content { get; set; }
public string RawData { get; set; }
}
这篇关于HttpListener如何提供图片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！
