一. 解决android6.0以上getScanResults()为空的情况
在android6.0以下采用getScanResults()就可以获取手机扫描的wifi信息，然而在6.0以上却得不到之前的信息。
这主要的问题在于android6.0扫描wifi信息必须打开获取位置权限
解决方法：
1.在AndroidManifest.xml添加相应的静态权限
检查自己有没有上述四项权限
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
2.在wifi获取信息之前动态申请权限，打开wifi以及gps
// 判断wifi是否开启
wifi = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
if(! wifi.isWifiEnabled()){
if(wifi.getWifiState() != WifiManager.WIFI_STATE_ENABLING)
wifi.setWifiEnabled(true);
}
{
···
// 判断是否有位置权限
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {//如果 API level 是大于等于 23(Android 6.0) 时
//判断是否具有权限
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
//判断是否需要向用户解释为什么需要申请该权限
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.ACCESS_COARSE_LOCATION)) {
//showToast("自Android 6.0开始需要打开位置权限");
}
//请求权限
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.ACCESS_COARSE_LOCATION},
REQUEST_CODE_ACCESS_COARSE_LOCATION);
}
}
···
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
if (requestCode == REQUEST_CODE_ACCESS_COARSE_LOCATION) {
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
//用户允许改权限，0表示允许，-1表示拒绝 PERMISSION_GRANTED = 0， PERMISSION_DENIED = -1
//permission was granted, yay! Do the contacts-related task you need to do.
//这里进行授权被允许的处理
} else {
//permission denied, boo! Disable the functionality that depends on this permission.
//这里进行权限被拒绝的处理
}
} else {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
}
}
3.检查手机是否打开了wifi以及gps按钮
以上三步就能解决android6.0以上无法通过getScanResults()获取扫描信息的问题
以下是我的实验结果截图：
二. 获取wifi信息的源码
package dick.android.remotecontrol;
import android.Manifest;
import android.content.Context;
import android.content.pm.PackageManager;
import android.net.wifi.ScanResult;
import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;
import android.os.Build;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import java.util.List;
public class WifiCollector extends AppCompatActivity {
WifiManager wifi;
TextView show;
Button button;
private static final int REQUEST_CODE_ACCESS_COARSE_LOCATION = 1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.wifi_data);
show = (TextView) findViewById(R.id.wifi_ssid);
button = findViewById(R.id.fresh);
// 判断wifi是否开启
wifi = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
if(! wifi.isWifiEnabled()){
if(wifi.getWifiState() != WifiManager.WIFI_STATE_ENABLING)
wifi.setWifiEnabled(true);
}
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {//如果 API level 是大于等于 23(Android 6.0) 时
//判断是否具有权限
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
//判断是否需要向用户解释为什么需要申请该权限
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.ACCESS_COARSE_LOCATION)) {
//showToast("自Android 6.0开始需要打开位置权限");
}
//请求权限
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.ACCESS_COARSE_LOCATION},
REQUEST_CODE_ACCESS_COARSE_LOCATION);
}
}
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
/**
* 获取当前连接上的wifi相关信息
*/
WifiInfo info = wifi.getConnectionInfo();
int strength = info.getRssi();
int speed = info.getLinkSpeed();
String bssid = info.getBSSID();
String ssid = info.getSSID();
String units = WifiInfo.LINK_SPEED_UNITS;
String wifiinformation = "ScanResults is: \n";
/**
* 获取扫描到的所有wifi相关信息
*/
List<ScanResult> results = wifi.getScanResults();
for(ScanResult result:results){
wifiinformation += "bssid为：" + result.BSSID+ " ssid为："+result.SSID+" 强度为："+result.level+"\n";
}
String text = "正连接的WiFi\nssid为：" + ssid + "\nbssid为：" +bssid + "\n连接速度为：" + String.valueOf(speed) + " " + String.valueOf(units) + "\n强度为：" + strength;
wifiinformation += "\n\n";
wifiinformation += text;
show.setText(wifiinformation);
}
});
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
if (requestCode == REQUEST_CODE_ACCESS_COARSE_LOCATION) {
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
//用户允许改权限，0表示允许，-1表示拒绝 PERMISSION_GRANTED = 0， PERMISSION_DENIED = -1
//permission was granted, yay! Do the contacts-related task you need to do.
//这里进行授权被允许的处理
} else {
//permission denied, boo! Disable the functionality that depends on this permission.
//这里进行权限被拒绝的处理
}
} else {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
}
}
}