微調烤箱吐司不顯示

Question

微調控制器有一個樂隊流派的數組列表，當選擇微調控制器中的任何類型時，它將顯示一個吐司，點擊微調器時沒有顯示吐司，代碼不顯示任何錯誤？任何想法爲什麼？

String spinnerSelection = null; 
    Spinner spinner = null; 

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



     ArrayAdapter<String> adapter = new ArrayAdapter<>(
       this, android.R.layout.simple_spinner_item, spinnerContent); 
     adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 


     spinner = (Spinner) findViewById(R.id.spinner); 
     spinner.setAdapter(adapter); 



     Button button = (Button) findViewById(R.id.button); 
     button.setOnClickListener(new View.OnClickListener() { 



                     public void onItemSelected(AdapterView<?>parent, View v, int position, long id) { 
     { 

      Toast.makeText(getBaseContext(),"Hell Yeah", Toast.LENGTH_SHORT).show(); 
     } 
    } 
    public void onNothingSelected(AdapterView<?> arg0) { 
    } 
} 

Answer 1

不要忘記添加點擊監聽器，微調

spinner.setOnItemClickListener(this); 

Answer 2

你對你的按鈕添加setOnClickListener（）。將setOnItemClickListener（）添加到您的微調器。

Answer 3

您需要把@Override設置爲onItemSelected(...)和onNothingSelected(...)的功能。

確保您設置一個監聽器上的微調： spinner.setOnItemClickListener(this);

編輯

public class MainActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener { 
    MediaPlayer myMusic; 
    int paused; 


    public void play(View view) { 
     if (myMusic == null) { 
      myMusic = MediaPlayer.create(this, R.raw.fast_and_cold); 
      myMusic.start(); 


     } 
    } 


    public void stop(View view) { 
     myMusic.reset(); 
     myMusic = null; 
    } 



    String spinnerSelection = null; 
    Spinner spinner = null; 

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



     final List<String> spinnerContent = new ArrayList<>(); 
     spinnerContent.add("Black Metal"); 
     spinnerContent.add("Death Metal"); 
     spinnerContent.add("Thrash Metal"); 
     spinnerContent.add("Heavy Metal"); 



     ArrayAdapter<String> adapter = new ArrayAdapter<>(
      this, android.R.layout.simple_spinner_item, spinnerContent); 

     adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 


     spinner = (Spinner) findViewById(R.id.spinner); 
     spinner.setAdapter(adapter); 
     spinner.setOnItemSelectedListener(this); // add this line 



     Button button = (Button) findViewById(R.id.button); 
     button.setOnClickListener(new View.OnClickListener() { 





    } 

    @Override // add this line 
    public void onItemSelected(AdapterView<?>parent, View v, int position, long id) { 


      Toast.makeText(getBaseContext(),"Show your Devil Horns !!", Toast.LENGTH_SHORT).show(); 

    } 

    @Override // add this line 
    public void onNothingSelected(AdapterView<?> arg0) { 

    } 

}