必须在按钮中点击2次以获得结果

Question

public void calcul（） FinalEditText vol; final EditText kil; final EditText缺点; context = getApplicationContext（）; vol =（EditText）findViewById（R.id.volume2）; kil =（EditText）findViewById（R.id.kilometrage2）; cons =（EditText）findViewById（R.id.consom2）;

final Button button = (Button) findViewById(R.id.button); 

button.setOnClickListener(new View.OnClickListener() { 
    public void onClick(View v) { 

String value1 = vol.getText().toString(); 
String value2 = kil.getText().toString(); 


        if (value1 != null && /*value1.trim().length() > 0 &&*/ value2 != null /*&& value2.trim().length() > 0*/) 
        { 
          float q1=Float.parseFloat(vol.getText().toString()); 
          float q2=Float.parseFloat(kil.getText().toString()); 
          float x=((q1/q2)* 100); 
          String y= Float.toString(x); 
          cons.setText(y); 

          SimpleDateFormat format = new SimpleDateFormat("dd/MM"); 
           String date = format.format(new Date()); 
           data = date + " : " + y + "L/100KM"+ " " + value1 + "L "+ value2 + "KM\n"; 
     SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context); 
     if (data != "") { 
     String fileName = getResources().getString(R.string.fileName); 
     String fileDir = ""+ preferences.getString("login", "") + "."+ preferences.getString("marque", "") + "."; 
     myIO.WriteSettings(context, fileDir + fileName, data); 
     data = ""; 

     Toast.makeText(carburant.this, "Donnée ajoutée!", Toast.LENGTH_SHORT).show(); 
           } 

        } 
        else 
        { 
        Toast.makeText(carburant.this, "Veuillez vérifier les deux champs", Toast.LENGTH_SHORT).show(); 
        } 
    } 

}）;

WriteSettings方法：

public class myIO { 
public static void WriteSettings(Context context, String nom, String data) { 
    FileOutputStream fOut = null; 
    OutputStreamWriter osw = null; 

    try { 
     fOut = context.openFileOutput(nom, Context.MODE_APPEND); 
     osw = new OutputStreamWriter(fOut); 
     osw.write(data); 
     osw.flush(); 
     osw.close(); 
     fOut.close(); 

    } catch (Exception e) { 
     Toast.makeText(context, "Echec", Toast.LENGTH_SHORT).show(); 
    } finally { 
     try { 
      osw.close(); 
      fOut.close(); 
     } catch (IOException e) { 
      Toast.makeText(context, "Echec", Toast.LENGTH_SHORT).show(); 
     } 
    } 
} 

Answer 1

如何将代码段被调用？什么是value1/value2？如果这是单击事件，则可能是第一次单击时value1或value2为空值，从而阻止更改任何设置。