try()-catch()中的问题 [英] Problem in try()-catch()

问题描述

HttpRes在尝试"部分中进行了初始化，但我无法在尝试"部分中的HttpRes中使用相同的数量

HttpRes take initialize in section Try, but i can''t use HttpRes in section Catch with the same amount in Try

   try
        {
            //Code Example
            string url = "http://www." + TextBox1.Text;
            HttpWebRequest httpReq = (HttpWebRequest)WebRequest.Create(url);
            httpReq.AllowAutoRedirect = false;

            HttpWebResponse httpRes = (HttpWebResponse)httpReq.GetResponse();
          
                Label1.Text = (((HttpWebResponse)httpRes).StatusDescription);
           
            // Close the response.
            httpRes.Close();
        }

catch
        {

            Label1.Text = (((HttpWebResponse)httpRes).StatusDescription);
               
        }

推荐答案

仔细查看您的代码.您没有关闭try块.

Hi,

Look into you code carefully. You are not closing your try block.

try
        {
            //Code Example
            string url = "http://www." + TextBox1.Text;
            HttpWebRequest httpReq = (HttpWebRequest)WebRequest.Create(url);
            httpReq.AllowAutoRedirect = false;
 
            HttpWebResponse httpRes = (HttpWebResponse)httpReq.GetResponse();
          
                Label1.Text = (((HttpWebResponse)httpRes).StatusDescription);
           
            // Close the response.
            httpRes.Close();
         }//This was not there you missed.
catch
        {
 
            Label1.Text = (((HttpWebResponse)httpRes).StatusDescription);
               
        }

只需在尝试使用Block之前声明httpRes

Just Declare The httpRes Before Try Block

 HttpWebResponse httpRes;
try
        {
            //Code Example
            string url = "http://www." + TextBox1.Text;
            HttpWebRequest httpReq = (HttpWebRequest)WebRequest.Create(url);
            httpReq.AllowAutoRedirect = false;
 
            httpRes = (HttpWebResponse)httpReq.GetResponse();
          
                Label1.Text = (((HttpWebResponse)httpRes).StatusDescription);
           
            // Close the response.
            httpRes.Close();
        }
 
catch
        {
 
            Label1.Text = (((HttpWebResponse)httpRes).StatusDescription);
               
        }

u像这样尝试之前先声明您的httpRes变量

u declare your httpRes variable before the try like this

HttpWebResponse httpRes;
try
        {
            //Code Example
            string url = "http://www." + TextBox1.Text;
            HttpWebRequest httpReq = (HttpWebRequest)WebRequest.Create(url);
            httpReq.AllowAutoRedirect = false;
 
            httpRes = (HttpWebResponse)httpReq.GetResponse();
          
                Label1.Text = (((HttpWebResponse)httpRes).StatusDescription);
           
            // Close the response.
            httpRes.Close();
         }//This was not there you missed.
catch
        {
 
            Label1.Text = (((HttpWebResponse)httpRes).StatusDescription);
               
        } 

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