如何創建一個微調器，可以從

Question

我正在創建一個練習應用程序，並且我逐字逐字地搜索，試圖找到如何創建一個顯示持續時間的微調，以及當用戶選擇持續時間，則選定的時間將出現在另一個活動的倒數計時器中。謝謝您的幫助！

Answer 1

希望這個代碼可以幫助你得到的正是你想要的

在您的第一項活動初始化微調

public class MainActivity extends AppCompatActivity { 

//Declare the ui component 
private Spinner spinner; 

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

    //initialize the ui component 
    spinner = (Spinner) findViewById(R.id.spinner); 

    //create a collection holding your desired time with a note first, we will check that later 
    // to find if the user selects a time 

    ArrayList<String> timer = new ArrayList<>(); 
    timer.add("Select your time"); 
    timer.add("10"); 
    timer.add("20"); 
    timer.add("30"); 
    timer.add("40"); 

    //create a adpter for the spinner and set that to the spinner 
    ArrayAdapter<String> spinnerAdapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, timer); 
    spinner.setAdapter(spinnerAdapter); 


    // create a onItemSelectedListener to get the user input from spinner 
    spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() { 
     @Override 
     public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) { 
      //get the selected text from spinner 
      String spinnerText = spinner.getSelectedItem().toString(); 


      //if the value is not "Select your time" then send them to another activity with intent 
      if (!spinnerText.contentEquals("Select your time")) { 

       Intent intent = new Intent(MainActivity.this, CountDownActivity.class); 
       intent.putExtra("time", spinnerText); 
       startActivity(intent); 
      } 
     } 

     @Override 
     public void onNothingSelected(AdapterView<?> adapterView) { 

     } 
    }); 
} 

和其他活動

public class CountDownActivity extends AppCompatActivity { 
TextView textView; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_count_down); 

    //initialize the ui component 
    textView = (TextView) findViewById(R.id.timeText); 

    //get the text from intent 
    String timerText = getIntent().getStringExtra("time"); 
    Toast.makeText(CountDownActivity.this, timerText, Toast.LENGTH_SHORT).show(); 

    //convert the string into integer 
    int time = Integer.valueOf(timerText); 

    //Initialize a CountDownTimer class with the time data from previous activity 
    //which will set the text view with countDown time 

    new CountDownTimer(time * 1000, 1000) { 
     public void onTick(long millisUntilFinished) { 
      //set the remaining time in the textView 
      textView.setText("seconds remaining: " + millisUntilFinished/1000); 
     } 

     public void onFinish() { 
      textView.setText("done!"); 
     } 
    }.start(); 
} 

}

如果您有任何問題的理解或這不符合您的要求請做毫不猶豫地回覆。 快樂編碼！

Answer 2

創建一個具有所需值的數組，並將其顯示在微調框中，並通過有關選定數字的回調通知感興趣的類。 在那裏你應該實現處理數字的邏輯。 您的問題太寬泛，無法更詳細地回答。

Answer 3

你需要在XML中創建一個字符串數組：

<?xml version="1.0" encoding="utf-8"?> 
<resources> 
    <string-array name="planets_array"> 
     <item>Mercury</item> 
     <item>Venus</item> 
     <item>Earth</item> 
     <item>Mars</item> 
     <item>Jupiter</item> 
     <item>Saturn</item> 
     <item>Uranus</item> 
     <item>Neptune</item> 
    </string-array> 
</resources> 

之後，陣列設置成微調使用適配器：

Spinner spinner = (Spinner) findViewById(R.id.spinner); 
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this, 
    R.array.planets_array, android.R.layout.simple_spinner_item); 
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 
spinner.setAdapter(adapter); 

顯然，而不是行星，時間。

更多信息here。