2017-01-01 32 views
5
public class AddStudentActivity extends AppCompatActivity { 

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

public void add2(View view){ 
    //create 3 editText , 1 Textview 
    EditText et_name, et_age; 
    RadioButton rb_male; 
    TextView tv_msg; 

    //bind with xml widget 
    et_name = (EditText)findViewById(R.id.et_name); 
    et_age = (EditText)findViewById(R.id.et_age); 
    rb_male = (RadioButton)findViewById(R.id.rb_male); 
    tv_msg = (TextView)findViewById(R.id.tv_msg); 
    //retrieve values 
    String name = et_name.getText().toString(); 
    String age = et_age.getText().toString(); 
    String gender = ""; 
    if (rb_male.isChecked()) 
     gender = "male"; 
    else 
     gender = "female"; 
    //call php 
    new AddStudent(this, tv_msg).execute(name, age, gender); 
    } 
} 

class AddStudent extends AsyncTask<String, Void, String> { 
private Context context; 
//CHANGE HERE....ADD PARAMATER 
TextView tv_msg; 

public AddStudent(Context context,TextView tv_msg) { 
    this.context = context; 
    this.tv_msg = tv_msg; 

} 

@Override 
protected String doInBackground(String[] arg) { 
    //CHANGE HERE ...... RETRIEVE STRING ARGUMENTS 
    String name = arg[0]; 
    String age = arg[1]; 
    String gender = arg[2]; 

    String link; 
    String data; 
    BufferedReader bufferedReader; 
    String result; 

    try { 
     //CHANGE HERE .... PARAMETERS 
      data = "?name=" + URLEncoder.encode(name, "UTF-8"); 
     data += "&age="+ URLEncoder.encode(age, "UTF-8"); 
     data += "&gender="+ URLEncoder.encode(gender, "UTF-8"); 
     //CHANGE HERE .... PHP PAGE 
      link = "http://10.0.2.2/fashionstudio/ADD3.php" + data; 

     URL url = new URL(link); 
     HttpURLConnection con = (HttpURLConnection) url.openConnection(); 

     bufferedReader = new BufferedReader(new InputStreamReader(con.getInputStream(), "UTF-8")); 
     result = bufferedReader.readLine(); 

     return result; 
    } catch (Exception e) { 
     Log.d("msg here", e.getMessage()); 
     Toast.makeText(context, "Error Exception", Toast.LENGTH_SHORT).show(); 
     return new String("Exception: " + e.getMessage()); 

    } 
} 

@Override 
protected void onPostExecute(String result) { 
    if (result != null) { 
     try { 
      JSONObject reader = new JSONObject(result); 
      //CHANGE HERE... RETRIEVE VALUES 
      String msg = reader.getString("msg"); 
      tv_msg.setText(msg); 
     } catch (Exception e) { 
      e.printStackTrace(); 
      Log.d("msg here", e.getMessage()); 
      Toast.makeText(context, "Error parsing JSON data.", Toast.LENGTH_SHORT).show(); 
     } 
    } else { 
     Toast.makeText(context, "Couldn't get any JSON data.", Toast.LENGTH_SHORT).show(); 
    } 
    } 
} 

我得到一個錯誤,當我在android系統不能()內螺紋已不叫Looper.prepare創建處理機3

E/AndroidRuntime點擊添加學生:致命異常:#的AsyncTask 1 進程:com.example.lenovo.yuwilson,PID:22199 java.lang.RuntimeException:在java執行doInBackground()時發生錯誤android.os.AsyncTask $ 3.done(AsyncTask.java:300) 。 util.concurrent.FutureTask.finishCompletion(FutureTask.java:355) at java.util.concurrent.Futur eTask.setException(FutureTask.java:222) 在java.util.concurrent.FutureTask.run(FutureTask.java:242) 在android.os.AsyncTask $ SerialExecutor $ 1.run(AsyncTask.java:231) 是java .util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112) 在java.util.concurrent.ThreadPoolExecutor中的$ Worker.run(ThreadPoolExecutor.java:587) 在java.lang.Thread.run(Thread.java:841 ) 引起:java.lang.RuntimeException:無法在android.os.Handler的android.os.Handler。(Handler.java:208) 未調用Looper.prepare() 的線程中創建處理程序。 (Handler.java:122) at android.widget.Toast $ TN。(Toast.java:341) at android.w idget.Toast。(Toast.java:96) 在android.widget.Toast.makeText(Toast.java:245) 在com.example.lenovo.yuwilson.AddStudent.doInBackground(AddStudentActivity.java:94) 在玉米(FutureTask.java:.example.lenovo.yuwilson.AddStudent.doInBackground(AddStudentActivity.java:54) at android.os.AsyncTask $ 2.call(AsyncTask.java:288) at java.util.concurrent.FutureTask.run(FutureTask.java: 237) at android.os.AsyncTask $ SerialExecutor $ 1.run(AsyncTask.java:231) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112) at java.util.concurrent.ThreadPoolExecutor $ Worker .run(ThreadPoolExecutor.java:587) at java.lang.Thread.run(Thread.java:841)

有人幫我解決一下嗎?

+4

的[無法創建內螺紋處理可能的複製這還沒有調用Looper.prepare()](http://stackoverflow.com/questions/3875184/cant-create-handler-inside-thread-that-has-not-called-looper-prepare) –

+0

@餘Wil兒子如果它滿足您的請求,請考慮接受下面的答案之一 – Lino

回答

6

你不能有

Toast.makeText(context, "Error Exception", Toast.LENGTH_SHORT).show(); 

doInBackground方法內。 Toast.makeText(...)必須在UI線程中執行。

2

試試這個:

runOnUiThread(new Runnable() { 
    public void run() { 
    Toast.makeText(context, "Error Exception", Toast.LENGTH_SHORT).show(); 
    } 
}); 

你需要調用Toast.makeText(...)從UI線程:因爲與用戶界面相關的功能不工作線程UI線程交易

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