Android：获取并解析json数据到列表视图

Question

我目前正在开发一个android项目，我希望能够按下一个按钮，并且它会将用户数据显示到另一个活动的列表视图中。我目前在某种意义上工作，但它需要我按两个按钮。一个从mysql数据库获取json数据，然后另一个将数据发送到下一个允许我显示它的活动。

我希望能有一种方法，这些方法都可以通过单击一次按钮来运行，或者在一个方法中都有。因为onPostExecute大干快上UI线程执行

public class MyMainActivity extends AppCompatActivity { 


String url = "http://192.168.20.120"; 
String json_string; 
View v; 

//Button to get the data 
ImageButton getUserDetailsBtn; 

//Button to parse the data 
ImageButton parseUserDetailsBtn; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_my_main); 

    getUserDetailsBtn= (ImageButton)findViewById(R.id.getUserDetailsButton);   

    parseUserDetailsBtn = (ImageButton)findViewById(R.id.parseUserDetailsButton); 

    getUserDetailsBtn.setVisibility(View.GONE); 


} 


// 
//get user details in app 
// 
public void getDetails(View view) { 

    new LoadUserDetails().execute(); 



    parseUserDetailsBtn .setVisibility(View.GONE); 
    getUserDetailsBtn= .setVisibility(View.VISIBLE); 



} 




//Load the user details 
class LoadUserDetails extends AsyncTask<Void,Void,String> 
{ 

    String json_url; 
    String JSON_STRING; 

    @Override 
    protected void onPreExecute() { 

     json_url = url+"/getUserDetails.php"; 
    } 

    @Override 
    protected String doInBackground(Void... voids){ 

     try{ 

      URL url = new URL(json_url); 
      HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection(); 
      InputStream inputStream = httpURLConnection.getInputStream(); 
      BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream)); 
      StringBuilder stringBuilder = new StringBuilder(); 


      while((JSON_STRING = bufferedReader.readLine())!=null) 
      { 

       stringBuilder.append(JSON_STRING+"\n"); 
      } 

      bufferedReader.close(); 
      inputStream.close(); 
      httpURLConnection.disconnect(); 
      return stringBuilder.toString().trim(); 

     } catch (MalformedJsonException e){ 
      e.printStackTrace(); 
     } catch (IOException e){ 
      e.printStackTrace(); 
     } 



     return null; 
    } 

    @Override 
    protected void onProgressUpdate(Void... values) { 
     super.onProgressUpdate(values); 
    } 


    @Override 
    protected void onPostExecute(String result) { 
     TextView textview = (TextView) findViewById(R.id.textview); 
     textview.setText(""); 
     json_string = result; 

    } 
} 




// 
//parse the data 
// 
public void parseJSON(View view) 
{ 

    if(json_string==null){ 
     Toast.makeText(getApplicationContext(), "First get JSON Data", Toast.LENGTH_LONG).show(); 

    } 
    else{ 
     Intent intent = new Intent(this, ShowUserActivity.class); 
     intent.putExtra("json_data", json_string); 
     startActivity(intent); 

    } 


} 

Answer 1

启动Activity从onPostExecute

@Override 
    protected void onPostExecute(String result) { 
     TextView textview = (TextView) findViewById(R.id.textview); 
     textview.setText(""); 
     json_string = result; 
     if(json_string==null){ 
      Toast.makeText(getApplicationContext(), "First get JSON Data",  Toast.LENGTH_LONG).show();  
     } 
     else{ 
      Intent intent = new Intent(MyMainActivity.this, ShowUserActivity.class); 
      // and change this to MyMainActivity.this 
      // this will point to your task instead of Activity 
      intent.putExtra("json_data", json_string); 
      startActivity(intent);  
     }  
    }