我是Xamarin的新手,我正尝试从互联网上获取一个简单的文本文件。我将获取文本文件并将其解析为xml。我可以使用一些示例来解析xml,所以我认为可以使用http get请求通过Internet获取文件内容就可以了。
我已经尝试了几个示例,并且经常有一些事情可以部分起作用,但是由于缺少方法定义或缺少程序集引用而无法使用。如果我可以克服一个错误,则此示例很有希望(请参见行注释):
我的进口
using System;
using Xamarin.Forms;
using System.Threading.Tasks;
using System.IO;
using System.Net;
我遇到的方法有问题:
public static async Task<string> MakeGetRequest(string url, string cookie)
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create (url);
request.ContentType = "text/html";
request.Method = "GET";
request.Headers ["Cookie"] = cookie;
var response = await request.GetResponseAsync ();//Type 'System.Net.HttpWebRequest' does not contain a definition for 'GetResponseAsync'
var respStream = response.GetResponseStream();
respStream.Flush ();
using (StreamReader sr = new StreamReader (respStream)) {
//Need to return this response
string strContent = sr.ReadToEnd ();
respStream = null;
return strContent;
}
}
最佳答案
我有些惊讶地在Microsoft Page上找到了答案
using System;
using Xamarin.Forms;
using System.Threading.Tasks;
using System.Net.Http;
using System.Diagnostics;
namespace pcl
{
public class mainPage : ContentPage
{
public mainPage ()
{
var url = "http://ohiovr.com/church_files/dayspringWesleyan/mainscreen.xml";
var myXMLstring = "";
Task task = new Task (() =>{
myXMLstring = AccessTheWebAsync (url).Result;
});
task.Start();
task.Wait();
Debug.WriteLine (myXMLstring);
Content = new StackLayout {
Children = {
new Label { Text = "Hello StackOverflow" }
}
};
}
async Task<String> AccessTheWebAsync(String url)
{
// You need to add a reference to System.Net.Http to declare client.
HttpClient client = new HttpClient();
// GetStringAsync returns a Task<string>. That means that when you await the
// task you'll get a string (urlContents).
Task<string> getStringTask = client.GetStringAsync(url);
// You can do work here that doesn't rely on the string from GetStringAsync.
//DoIndependentWork();
// The await operator suspends AccessTheWebAsync.
// - AccessTheWebAsync can't continue until getStringTask is complete.
// - Meanwhile, control returns to the caller of AccessTheWebAsync.
// - Control resumes here when getStringTask is complete.
// - The await operator then retrieves the string result from getStringTask.
string urlContents = await getStringTask;
// The return statement specifies an integer result.
// Any methods that are awaiting AccessTheWebAsync retrieve the length value.
return urlContents;
}
}
}
关于c# - Xamarin可移植类库中的简单获取请求(我需要它才能在iOS和Windows Phone上运行),我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/31493508/