無法在我的Async類中找到方法

Question

我正在創建一個Android應用程序，該應用程序可以使用HTTP DELETE從JSON中刪除數據。但我面臨的問題。我創建了2個不同的文件。 MainActivity和Async之一。

MainActivity.java

public class MainActivity extends AppCompatActivity { 

@Override 
protected void onCreate(Bundle savedInstanceState) { 

    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
    setSupportActionBar(toolbar); 
    onClickButtonListner(); 
} 

public void onClickButtonListner() { 
    final Button btn = (Button) findViewById(R.id.delete_btn); 
    final String URL = myurl; 
    btnDelete.setOnClickListener(
      new View.OnClickListener() { 
       @Override 
       public void onClick(View v) { 
        Async asyn = new Async(URL); 
        asyn.execute(); 
       } 
      }); 
} 
} 

Async.java

public class Async extends AsyncTask<Void, Void, String> { 
String murl; 
public Async(String url) { 
    murl = url; 
} 

@Override 
protected String doInBackground(Void... params) { 
    HttpURLConnection httpURLConnection; 
    URL url ; 
    try { 
     final EditText id= (EditText)findViewById(R.id.delete_id); 
     **showing unable to resolve method findViewById** 
     String delete_url = murl + "/" + id.getText().toString(); 
     url = new URL(delete_url); 
     httpURLConnection = (HttpURLConnection) url.openConnection(); 
     httpURLConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); 
     httpURLConnection.setRequestMethod("DELETE"); 
     httpURLConnection.connect(); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 
    return null; 
} 

@Override 
protected void onPostExecute(String result) { 
    super.onPostExecute(result); 
} 

}

所以我的問題是，我的異步類是顯示無法找到findViewById方法。

所以，請幫助我如何解決這個問題 謝謝

Answer 1

試圖改變如下代碼：

MainActivity.java

public class MainActivity extends AppCompatActivity { 

@Override 
protected void onCreate(Bundle savedInstanceState) { 

super.onCreate(savedInstanceState); 
setContentView(R.layout.activity_main); 
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
setSupportActionBar(toolbar); 
onClickButtonListner(); 
} 

public void onClickButtonListner() { 
final Button btn = (Button) findViewById(R.id.delete_btn); 
final String URL = myurl; 
final EditText id= (EditText)findViewById(R.id.delete_id); 
btnDelete.setOnClickListener(
     new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       Async asyn = new Async(URL,id.getText().toString()); 
       asyn.execute(); 
      } 
     }); 
} 
} 

Async.java

public class Async extends AsyncTask<Void, Void, String> { 
String murl,id; 
public Async(String url,String _id) { 
    murl = url; 
    id=_id; 
} 

@Override 
protected String doInBackground(Void... params) { 
    HttpURLConnection httpURLConnection; 
    URL url ; 
    try { 
     String delete_url = murl + "/" + id; 
     url = new URL(delete_url); 
     httpURLConnection = (HttpURLConnection) url.openConnection(); 
     httpURLConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); 
     httpURLConnection.setRequestMethod("DELETE"); 
     httpURLConnection.connect(); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 
    return null; 
} 

@Override 
protected void onPostExecute(String result) { 
    super.onPostExecute(result); 
} 
}