我正在尝试使用来自 MySQL 的数据填充微调器(我必须行),但它们保持为空。此外,这些微调器应该相互依赖。任何想法为什么?当我在本地主机中调用 url 时,它返回正确的值,因此 PHP 工作正常(PHP 中的一行示例:[{"Grad":"Beograd","Predmet":"matematika"}...],我我更担心将这些行放在列表中。
public class IzboraGrada extends Activity {
Spinner spinner1, spinner2;
private Button button,izlaz;
static String str_grad,str_predmet,url;
InputStream is=null;
String result=null;
String line=null;
String[] grad, predmet;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_izbora_grada);
spinner1=(Spinner) findViewById(R.id.spinner1);
spinner2=(Spinner) findViewById(R.id.spinner2);
final List<String> list1=new ArrayList<String>();
final List<String> list2=new ArrayList<String>();
Button b=(Button) findViewById(R.id.button);
b.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
try
{
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://192.168.1.14/test/spinner1.php");
HttpResponse response = httpclient.execute(httppost);
Log.e("Fail 1", "3");
HttpEntity entity = response.getEntity();
Log.e("Fail 1", "4");
is = entity.getContent();
Log.e("Pass 1", "connection success ");
}
catch(Exception e)
{
Log.e("Fail 1", e.toString());
Toast.makeText(getApplicationContext(), "Invalid IP Address",Toast.LENGTH_LONG).show();
finish();
}
try
{
BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
while ((line = reader.readLine()) != null)
{
sb.append(line + "\n");
}
is.close();
result = sb.toString();
}
catch(Exception e)
{
Log.e("Fail 2", e.toString());
}
try
{
JSONArray JA=new JSONArray(result);
JSONObject json= null;
grad = new String[JA.length()];
predmet = new String[JA.length()];
for(int i=0;i<JA.length();i++)
{
json=JA.getJSONObject(i);
grad[i] = json.getString("Grad");
predmet[i]=json.getString("Predmet");
}
Toast.makeText(getApplicationContext(), "sss",Toast.LENGTH_LONG).show();
for(int i=0;i<grad.length;i++)
{
list1.add(grad[i]);
list2.add(predmet[i]);
}
spinner_fn();
}
catch(Exception e)
{
Log.e("Fail 3", e.toString());
//login.this.finish();
}
}
});
}
private void spinner_fn() {
// TODO Auto-generated method stub
ArrayAdapter<String> dataAdapter1 = new ArrayAdapter<String>(getApplicationContext(),
android.R.layout.simple_spinner_item, grad);
dataAdapter1.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner1.setAdapter(dataAdapter1);
ArrayAdapter<String> dataAdapter2 = new ArrayAdapter<String>(getApplicationContext(),
android.R.layout.simple_spinner_item, predmet);
dataAdapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner2.setAdapter(dataAdapter2);
spinner1.setOnItemSelectedListener(new OnItemSelectedListener()
{
public void onItemSelected(AdapterView<?> arg0, View arg1,int position, long id)
{
// TODO Auto-generated method stub
spinner2.setSelection(position);
}
@Override
public void onNothingSelected(AdapterView<?> arg0)
{
// TODO Auto-generated method stub
}
});
spinner2.setOnItemSelectedListener(new OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> arg0, View arg1,int position, long arg3) {
// TODO Auto-generated method stub
spinner1.setSelection(position);
}
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
}
});
}
}
和PHP代码:
$con = mysqli_connect($host, $user, $pwd, $db);
if(mysqli_connect_errno($con)) {
die("Failed to connect to MySQL: " . mysqli_connect_error());
}
$sql = "SELECT Grad, Predmet FROM lista";
$result = mysqli_query($con, $sql);
$rows = array();
while($row = mysqli_fetch_array($result, MYSQLI_ASSOC)) {
$rows[] = $row;
}
mysqli_close($con);
echo json_encode($rows);