java微调器onItemSelectedListener不工作?
我使用了一个Android 4.4
并且有问题implementing a spinner
。
问题:从列表中选择选定项时,微调器未设置选定项
根据this和其他我尝试过的帖子,似乎没有任何解决方案适合我,我是否错过了一些我只是没有意识到的非常重要的东西
程序应该做什么:我确实希望扫描wifi网络,并希望用户从微调器中选择wifi连接并进行设置
当前情况:微调器显示可用的wifi网络,但当我单击其中一个时,它未被选中
public class SetupActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener
{
private WifiManager wifiManager;
private ListView listView;
private Button buttonScan;
private int size = 0;
private List<ScanResult> results;
private ArrayList<String> arrayList = new ArrayList<>();
private ArrayAdapter adapter;
private Spinner spinner;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate( savedInstanceState );
setContentView( R.layout.activity_setup );
buttonScan = findViewById(R.id.btnScan);
buttonScan.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
scanWifi();
}
});
spinner = findViewById(R.id.spinnerSSID);
listView = findViewById(R.id.wifiList);
wifiManager = (WifiManager) getApplicationContext().getSystemService( Context.WIFI_SERVICE);
if (!wifiManager.isWifiEnabled()) {
Toast.makeText(this, "WiFi is disabled ... We need to enable it", Toast.LENGTH_LONG).show();
wifiManager.setWifiEnabled(true);
}
adapter = new ArrayAdapter<>(this, 安卓.R.layout.simple_list_item_1, arrayList);
listView.setAdapter(adapter);
scanWifi();
ArrayAdapter<String> adp = new ArrayAdapter<String>(SetupActivity.this,
安卓.R.layout.simple_spinner_item, arrayList );
adapter.setDropDownViewResource(安卓.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adp);
spinner.setOnItemSelectedListener(this);
}
private void scanWifi() {
arrayList.clear();
registerReceiver(wifiReceiver, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));
wifiManager.startScan();
Toast.makeText(this, "Scanning WiFi ...", Toast.LENGTH_SHORT).show();
}
BroadcastReceiver wifiReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
results = wifiManager.getScanResults();
unregisterReceiver(this);
for (ScanResult scanResult : results) {
arrayList.add(scanResult.SSID + " - " + scanResult.capabilities);
adapter.notifyDataSetChanged();
}
}
};
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
parent.getItemAtPosition(position);
Toast.makeText(parent.getContext(),
"OnItemSelectedListener : " + parent.getItemAtPosition(position).toString(),
Toast.LENGTH_SHORT).show();
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
}
下面是布局中的xml:
<?xml version="1.0" encoding="utf-8"?>
<安卓x.constraintlayout.widget.ConstraintLayout xmlns:安卓="http://schemas.安卓.com/apk/res/安卓"
xmlns:app="http://schemas.安卓.com/apk/res-auto"
xmlns:tools="http://schemas.安卓.com/tools"
安卓:layout_width="match_parent"
安卓:layout_height="match_parent"
安卓:tint="?attr/colorControlNormal"
tools:context=".SetupActivity">
<TextView
安卓:id="@+id/textView3"
安卓:layout_width="wrap_content"
安卓:layout_height="wrap_content"
安卓:text="DeviceID: 1234abcd"
app:layout_constraintBottom_toTopOf="@+id/textView4"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/textView2" />
<TextView
安卓:id="@+id/textView"
安卓:layout_width="wrap_content"
安卓:layout_height="wrap_content"
安卓:layout_marginTop="16dp"
安卓:text="Setup"
安卓:textSize="36sp"
app:layout_constraintBottom_toTopOf="@+id/textView2"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
安卓:id="@+id/textView2"
安卓:layout_width="wrap_content"
安卓:layout_height="wrap_content"
安卓:text="No Content Installed!"
app:layout_constraintBottom_toTopOf="@+id/textView3"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/textView" />
<TextView
安卓:id="@+id/textView4"
安卓:layout_width="wrap_content"
安卓:layout_height="wrap_content"
安卓:text="Choose which Setup"
安卓:textSize="30sp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/textView3" />
<TextView
安卓:id="@+id/textView11"
安卓:layout_width="wrap_content"
安卓:layout_height="wrap_content"
安卓:layout_marginStart="240dp"
安卓:layout_marginTop="196dp"
安卓:text="Local"
安卓:textSize="24sp"
安卓:textStyle="bold"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
安卓:id="@+id/textView12"
安卓:layout_width="wrap_content"
安卓:layout_height="wrap_content"
安卓:layout_marginTop="196dp"
安卓:layout_marginEnd="240dp"
安卓:text="Online"
安卓:textSize="24sp"
安卓:textStyle="bold"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ImageView
安卓:id="@+id/imageView6"
安卓:layout_width="432dp"
安卓:layout_height="297dp"
安卓:layout_marginStart="16dp"
安卓:layout_marginTop="24dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/textView11"
app:srcCompat="@drawable/usbstick" />
<ImageView
安卓:id="@+id/imageView8"
安卓:layout_width="11dp"
安卓:layout_height="252dp"
安卓:layout_marginTop="150dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/textView4"
app:srcCompat="@color/colorPrimary" />
<EditText
安卓:id="@+id/etxtContentId"
安卓:layout_width="445dp"
安卓:layout_height="44dp"
安卓:layout_marginTop="63dp"
安卓:layout_marginEnd="3dp"
安卓:ems="10"
安卓:hint="Content ID"
安卓:inputType="textPersonName"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="@+id/imageView6"
app:layout_constraintTop_toBottomOf="@+id/textView12" />
<EditText
安卓:id="@+id/etxtWifiPassword"
安卓:layout_width="445dp"
安卓:layout_height="44dp"
安卓:layout_marginTop="8dp"
安卓:layout_marginEnd="3dp"
安卓:ems="10"
安卓:hint="Wifi Password"
安卓:inputType="textPersonName"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="1.0"
app:layout_constraintStart_toEndOf="@+id/imageView6"
app:layout_constraintTop_toBottomOf="@+id/spinnerSSID" />
<Spinner
安卓:id="@+id/spinnerSSID"
安卓:layout_width="447dp"
安卓:layout_height="44dp"
安卓:layout_marginStart="1dp"
安卓:layout_marginTop="38dp"
安卓:spinnerMode="dropdown"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="@+id/imageView6"
app:layout_constraintTop_toBottomOf="@+id/etxtContentId" />
<Button
安卓:id="@+id/btnTestConnection"
安卓:layout_width="wrap_content"
安卓:layout_height="wrap_content"
安卓:layout_marginStart="20dp"
安卓:layout_marginTop="24dp"
安卓:text="Test Connection"
app:layout_constraintStart_toEndOf="@+id/imageView6"
app:layout_constraintTop_toBottomOf="@+id/etxtWifiPassword" />
<Button
安卓:id="@+id/btnWifiConnect"
安卓:layout_width="wrap_content"
安卓:layout_height="wrap_content"
安卓:layout_marginStart="12dp"
安卓:layout_marginTop="24dp"
安卓:text="Connect"
app:layout_constraintStart_toEndOf="@+id/btnTestConnection"
app:layout_constraintTop_toBottomOf="@+id/etxtWifiPassword" />
<Button
安卓:id="@+id/btnFinish"
安卓:layout_width="392dp"
安卓:layout_height="45dp"
安卓:layout_marginStart="13dp"
安卓:layout_marginTop="9dp"
安卓:layout_marginEnd="43dp"
安卓:text="Finish and perform online update"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="@+id/imageView6"
app:layout_constraintTop_toBottomOf="@+id/btnTestConnection" />
<Button
安卓:id="@+id/btnScan"
安卓:layout_width="wrap_content"
安卓:layout_height="wrap_content"
安卓:layout_marginStart="27dp"
安卓:layout_marginTop="25dp"
安卓:text="Scan"
app:layout_constraintStart_toEndOf="@+id/btnWifiConnect"
app:layout_constraintTop_toBottomOf="@+id/etxtWifiPassword" />
<ListView
安卓:id="@+id/wifiList"
安卓:layout_width="412dp"
安卓:layout_height="99dp"
安卓:layout_marginTop="1dp"
安卓:layout_marginEnd="2dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</安卓x.constraintlayout.widget.ConstraintLayout>
重要的部分在活动和布局中。xml
private Spinner spinner;
...
spinner = findViewById(R.id.spinnerSSID);
...
ArrayAdapter<String> adp = new ArrayAdapter<String>(SetupActivity.this,
安卓.R.layout.simple_spinner_item, arrayList );
adapter.setDropDownViewResource(安卓.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adp);
spinner.setOnItemSelectedListener( new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
parent.getItemAtPosition(position);
Toast.makeText(parent.getContext(),
"OnItemSelectedListener : " + parent.getItemAtPosition(position).toString(),
Toast.LENGTH_SHORT).show();
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
parent.getItemAtPosition(0);
Toast.makeText(parent.getContext(),
"OnItemSelectedListener : " + parent.getItemAtPosition(0).toString(),
Toast.LENGTH_SHORT).show();
}
} );
在XML中:
<Spinner
安卓:id="@+id/spinnerSSID"
安卓:layout_width="447dp"
安卓:layout_height="44dp"
安卓:layout_marginStart="1dp"
安卓:layout_marginTop="38dp"
安卓:spinnerMode="dropdown"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="@+id/imageView6"
app:layout_constraintTop_toBottomOf="@+id/etxtContentId" />
提前谢谢你的帮助
编辑:我在控制台中注意到这个错误:
E/dalvikvm: Could not find class '安卓.widget.ThemedSpinnerAdapter', referenced from method 安卓x.appcompat.widget.AppCompatSpinner$DropDownAdapter.<init>
在调试器中,我注意到侦听器没有被调用
# 1 楼答案
使用
将适配器设置为微调器时。 我查过了
注意:您的适配器“adp”有问题。我不知道你为什么用这个