如何让微调取决于另一个微调

Question

我正在构建一个由spinners和edittext组成的简单应用程序。 问题是，我有2个纺纱与阵列中的适配器

微调1

ArrayAdapter adapter1 = ArrayAdapter.createFromResource(this,R.array.kendaraan_arrays,android.R.layout.simple_spinner_item); 
    spKendaraan.setAdapter(adapter1); 

我要的是从微调2个阵列是取决于我在微调选择1

微调2

@Override 
    public void onItemSelected (AdapterView <?> adapterView, View view,int position, long id){ 
    if (spKendaraan.getSelectedItem().equals("Mobil")) { 
     Toast.makeText(getApplicationContext(), "Mobil dipilih", Toast.LENGTH_SHORT).show(); 
     ArrayAdapter adapter2 = ArrayAdapter.createFromResource(this, R.array.pelanggaran_mobil, android.R.layout.simple_spinner_item); 
     spPelanggaran.setAdapter(adapter2); 
    } else { 
     ArrayAdapter adapter2 = ArrayAdapter.createFromResource(this, R.array.pelanggaran_motor, android.R.layout.simple_spinner_item); 
     spPelanggaran.setAdapter(adapter2); 
    } 
} 

我上面的代码不工作，我在做逻辑/方法错误？

TL;博士

if spinnerA == x{ 
spinnerB = m 
} 
else { 
spinnerB = n 
} 

，因为我是android的新的，任何例子是非常赞赏。

Answer 1

我不知道为什么你的代码不工作，但以下是一个示例代码为你工作，你需要，我希望这会有所帮助。

XML布局文件：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:paddingBottom="@dimen/activity_vertical_margin" 
    android:paddingLeft="@dimen/activity_horizontal_margin" 
    android:paddingRight="@dimen/activity_horizontal_margin" 
    android:paddingTop="@dimen/activity_vertical_margin" 
    tools:context="com.example.stackspinner.MainActivity" > 

<Spinner 
    android:id="@+id/spinner1" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" /> 

<Spinner 
    android:id="@+id/spinner2" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:layout_below="@+id/spinner1" /> 

</RelativeLayout> 

活动：

public class MainActivity extends Activity implements OnItemSelectedListener { 

Spinner spinner1, spinner2; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    spinner1 = (Spinner) findViewById(R.id.spinner1); 
    spinner2 = (Spinner) findViewById(R.id.spinner2); 
    ArrayAdapter adapter1 = ArrayAdapter.createFromResource(this, 
      R.array.array1, android.R.layout.simple_spinner_item); 
    spinner1.setAdapter(adapter1); 
    spinner1.setOnItemSelectedListener(this); 
} 

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.menu.main, menu); 
    return true; 
} 

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    // Handle action bar item clicks here. The action bar will 
    // automatically handle clicks on the Home/Up button, so long 
    // as you specify a parent activity in AndroidManifest.xml. 
    int id = item.getItemId(); 
    if (id == R.id.action_settings) { 
     return true; 
    } 
    return super.onOptionsItemSelected(item); 
} 

@Override 
public void onItemSelected(AdapterView<?> parent, View view, int position, 
     long id) { 
    if (spinner1.getSelectedItem().equals("mobile")) { 
     Toast.makeText(getApplicationContext(), "Mobil dipilih", 
       Toast.LENGTH_SHORT).show(); 

     ArrayAdapter adapter2 = ArrayAdapter.createFromResource(this, 
       R.array.mobile_array, android.R.layout.simple_spinner_item); 
     spinner2.setAdapter(adapter2); 
    } else { 
     ArrayAdapter adapter2 = ArrayAdapter.createFromResource(this, 
       R.array.motor_array, android.R.layout.simple_spinner_item); 
     spinner2.setAdapter(adapter2); 
    } 

} 

@Override 
public void onNothingSelected(AdapterView<?> parent) { 
    // TODO Auto-generated method stub 
} 

} 

字符串：

<resources> 

<string name="app_name">Application Name</string> 
<string name="hello_world">Hello world!</string> 
<string name="action_settings">Settings</string> 

<string-array name="array1"> 
    <item>mobile</item> 
    <item>motor</item> 
</string-array> 
<string-array name="mobile_array"> 
    <item>Android</item> 
    <item>blackberry</item> 
    <item>apple</item> 
</string-array> 
<string-array name="motor_array"> 
    <item>Audi</item> 
    <item>BMW</item> 
    <item>unicorn</item> 
</string-array> 

Answer 2

我可以看到，这条线，而不是this下面你可以写getApplicationContext()或getBaseContext()所以实际的代码应该是内部onItemSelected

ArrayAdapter adapter2 = ArrayAdapter.createFromResource(getBaseContext(), R.array.pelanggaran_mobil, android.R.layout.simple_spinner_item); 

，我认为它应该工作现在。请让我知道如果你有这个问题:)