Question

我正在创建一个能够使用HTTP DELETE从JSON中删除数据的Android应用程序。但是我遇到了问题。我创建了2个不同的文件。 MainActivity和Async中的其中一个。

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);
}

}

所以我的问题是我的Async类显示无法找到findViewById方法。

所以请帮我解决这个问题谢谢

Answer 1

尝试更改您的代码，如下所示：

<强> 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();
            }
        });
}
}

<强> 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);
}
}

无法在我的Async类中找到方法

1 个答案: