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I’m creating an App that looks for nearby wifi networks and then can connect to them, but locked at the beginning, because I can make it scan, but when I click on some network of the list, which would redirect me to another Acitiviry, the app hangs and Fexa, why? Mainacitivity.java
package com.emanuel.testes;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.wifi.ScanResult;
import android.net.wifi.WifiManager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private WifiManager wifiManager;
private ListView listView;
private Button buttonScan;
private List<ScanResult> results;
private ArrayList<String> arrayList = new ArrayList<>();
private ArrayAdapter adapter;
private boolean f = false;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
buttonScan = findViewById(R.id.scanBtn);
buttonScan.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
scanWifi();
}
});
listView = findViewById(R.id.wifiList);
wifiManager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
if (!wifiManager.isWifiEnabled()) {
Toast.makeText(this, "Wifi está desativado. Eu vou ativa-lo por você.", Toast.LENGTH_LONG).show();
wifiManager.setWifiEnabled(true);
}
adapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, arrayList);
listView.setAdapter(adapter);
scanWifi();
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
Intent intent = new Intent(MainActivity.this, Element.class);
startActivity(intent);
f = true;
}
});
if(f) {
this.finish();
}
}
private void scanWifi() {
arrayList.clear();
registerReceiver(wifiReceiver, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));
wifiManager.startScan();
Toast.makeText(this, "Procurando ESPs...", Toast.LENGTH_LONG).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);
adapter.notifyDataSetChanged();
}
}
};
}
Element.java
package com.emanuel.testes;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
public class Element extends AppCompatActivity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.content_main);
}
}
activity_main
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<Button
android:id="@+id/scanBtn"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginBottom="8dp"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="4dp"
android:text="@string/procurar_esps"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/wifiList" />
<ListView
android:id="@+id/wifiList"
android:layout_width="368dp"
android:layout_height="439dp"
android:layout_marginBottom="4dp"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
app:layout_constraintBottom_toTopOf="@+id/scanBtn"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
content_main
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="8dp"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
android:text="FUNCIONA POR FAVOR"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
You declared your Activity Element in manisfest?
– Rafael Henrique Fernandes