java - 如何将微调器与我的转换器连接

Question

1. 我需要将微调器与 editText 连接以获得转换器的结果

   微调器和我的转换器之间没有连接。

   public class A01Acre extends Activity {
       Spinner spinnerarea;
   
       @Override
       protected void onCreate(Bundle savedInstanceState) {
           // TODO Auto-generated method stub
           super.onCreate(savedInstanceState);
           setContentView(R.layout.a01acre);  
   
   
           final    EditText editAcre = (EditText) findViewById(R.id.editAcre);        
           final    EditText editHectar = (EditText) findViewById(R.id.editHectar);        
           final    EditText editSquareinch = (EditText) findViewById(R.id.editSquareinch);
           final    EditText editSquarekm = (EditText) findViewById(R.id.editSquarekm);
           final    EditText editSquaremeter = (EditText) findViewById(R.id.editSquaremeter);
           final    EditText editSquaremile = (EditText) findViewById(R.id.editSquaremile);
           final    EditText editSquareyard = (EditText) findViewById(R.id.editSquareyard);
   
           Button buttonConvert = (Button) findViewById (R.id.buttonConvertAcre);
           buttonConvert.setOnClickListener(new OnClickListener() {
   
               @Override
               public void onClick(View v) {
                   // TODO Auto-generated method stub
   
                   //try
                   try {
                       //    
                       double acre = Double.valueOf (editAcre.getText().toString());
                       double hectar = acre * 0.404686;
                       double squareinch = acre * 6.273e+6;
                       double squarekm = acre * 0.00404686;
                       double squaremeter = acre * 4046.86;
                       double squaremile = acre * 0.0015625;
                       double squareyard = acre * 4840;
   
   
                       editHectar.setText (String.valueOf(hectar));
                       editSquareinch.setText (String.valueOf(squareinch));
                       editSquarekm.setText (String.valueOf(squarekm));                    
                       editSquaremeter.setText (String.valueOf(squaremeter));
                       editSquaremile.setText (String.valueOf(squaremile));                    
                       editSquareyard.setText (String.valueOf(squareyard));        
   
                       //catch
                   } catch (NumberFormatException ex) {
                       // write a message to users
                       editHectar.setText ("");
                   }
               }
   
   
           });
   
   
           spinnerarea = (Spinner) findViewById(R.id.spinnerarea);
   
           ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
                   this, R.array.spinnerTestArray, android.R.layout.simple_spinner_item);
           adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
           spinnerarea.setAdapter(adapter);
           spinnerarea.setOnItemSelectedListener(new MyOnItemSelectdListerne());
       }
   
       @Override
       public void onDestroy(){
           super.onDestroy();
       }
   
   
       public class MyOnItemSelectdListerne implements OnItemSelectedListener {
   
           @Override
           public void onItemSelected(AdapterView<?> patent,
                   View view, int pos, long id) {
               String str = patent.getItemAtPosition(pos).toString().toUpperCase();
           }
   
           @Override
           public void onNothingSelected(AdapterView parent) {
   
   
   
   
           }
       }
   }
   

Answer 1

在您的方法中添加一个 switch 语句onItemSelected()- 开启pos。

对于每个单位（每个case），您可以重新计算，然后将值输出给用户。

就像是，

switch(pos) {
    case 0:
        //acre - redo calculation
        break;
    case 1:
        //hectare - redo calculation
        break;
    case 2:
        //squareinch - redo calculation
        break;
    //...
    default:
        throw new UnexpectedException();
}

//display results to user