Android電池電量檢測問題

Question

我是stackoverflow的新用戶，這是我的第一篇文章，如果我做錯了什么請隨時告訴我，謝謝。

我正在開發一個Android應用程序來監控電池電量和更改屏幕亮度，但我有一個奇怪的問題，谷歌搜索多次后找不到它。

public class SmartBrightnessProcessor extends BroadcastReceiver{

Context mContext;
IntentFilter intentFilter;
ContentResolver contentResolver;

public SmartBrightnessProcessor(Context context){
    this.mContext = context;
    intentFilter = new IntentFilter();
    intentFilter.addAction(Intent.ACTION_BATTERY_CHANGED);
}
public void registerReceiver(){
    mContext.registerReceiver(this, intentFilter);
}
public void unRegisterReceiver(){
    mContext.unregisterReceiver(this);
}
@Override
public void onReceive(Context context, Intent intent){

    contentResolver = context.getContentResolver();

    boolean isEnabled = context.getSharedPreferences("SmartBrightness",
            Context.MODE_PRIVATE).getBoolean("SmartBrightness", false);

    int batteryLevel = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, 0);

    if(isEnabled){
        if(Build.VERSION.SDK_INT >= 23){
            if(Settings.System.canWrite(context)){
                if(batteryLevel >= 70){
                    Settings.System.putInt(contentResolver, Settings.System.SCREEN_BRIGHTNESS, 85);
                }else if(batteryLevel >= 50 && batteryLevel <= 69){
                    Settings.System.putInt(contentResolver, Settings.System.SCREEN_BRIGHTNESS, 70);
                }else if(batteryLevel >= 20 && batteryLevel <= 49){
                    Settings.System.putInt(contentResolver, Settings.System.SCREEN_BRIGHTNESS, 50);
                }else if(batteryLevel >= 10 && batteryLevel <= 19){
                    Settings.System.putInt(contentResolver, Settings.System.SCREEN_BRIGHTNESS, 30);
                }else if(batteryLevel <= 9){
                    Settings.System.putInt(contentResolver, Settings.System.SCREEN_BRIGHTNESS, 10);
                }
            }
        }else{
            if(batteryLevel >= 70){
                Settings.System.putInt(contentResolver, Settings.System.SCREEN_BRIGHTNESS, 85);
            }else if(batteryLevel >= 50 && batteryLevel <= 69){
                Settings.System.putInt(contentResolver, Settings.System.SCREEN_BRIGHTNESS, 70);
            }else if(batteryLevel >= 20 && batteryLevel <= 49){
                Settings.System.putInt(contentResolver, Settings.System.SCREEN_BRIGHTNESS, 50);
            }else if(batteryLevel >= 10 && batteryLevel <= 19){
                Settings.System.putInt(contentResolver, Settings.System.SCREEN_BRIGHTNESS, 30);
            }else if(batteryLevel <= 9){
                Settings.System.putInt(contentResolver, Settings.System.SCREEN_BRIGHTNESS, 10);
            }
        }
    }
}

}

當我在真實設備中測試時上面的代碼工作正常，但我想在用戶啟用此選項時立即設置屏幕亮度，因此當用戶單擊按鈕時，我使用此代碼執行操作。

public class SmartBrightness extends Fragment {

SharedPreferences sharedPreferences;
Context context;
ContentResolver contentResolver;
Intent intent;
int batteryLevel;
Switch aSwitch;

public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){

    View view = inflater.inflate(R.layout.smart_brightness, container, false);

    context = getActivity().getApplicationContext();

    sharedPreferences = getActivity().getSharedPreferences("SmartBrightness", 0);
    Boolean smartBrightness = sharedPreferences.getBoolean("SmartBrightness", false);

    aSwitch = (Switch)view.findViewById(R.id.switch1);

    aSwitch.setChecked(smartBrightness);

    intent = new Intent();

    contentResolver = context.getContentResolver();

    batteryLevel = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, 0);

    aSwitch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {

        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            if(isChecked){
                if(Build.VERSION.SDK_INT >= 23){
                    if(!writeSettingsPermissionGranted()){
                        showMissingPermissionDialog();
                        aSwitch.setChecked(false);
                        SharedPreferences.Editor editor = sharedPreferences.edit();
                        editor.putBoolean("SmartBrightness", false);
                        editor.apply();
                    }else{
                        if(batteryLevel >= 70){
                            Settings.System.putInt(contentResolver, Settings.System.SCREEN_BRIGHTNESS, 85);
                        }else if(batteryLevel >= 50 && batteryLevel <= 69){
                            Settings.System.putInt(contentResolver, Settings.System.SCREEN_BRIGHTNESS, 70);
                        }else if(batteryLevel >= 20 && batteryLevel <= 49){
                            Settings.System.putInt(contentResolver, Settings.System.SCREEN_BRIGHTNESS, 50);
                        }else if(batteryLevel >= 10 && batteryLevel <= 19){
                            Settings.System.putInt(contentResolver, Settings.System.SCREEN_BRIGHTNESS, 30);
                        }else if(batteryLevel <= 9){
                            Settings.System.putInt(contentResolver, Settings.System.SCREEN_BRIGHTNESS, 10);
                        }
                        SharedPreferences.Editor editor = sharedPreferences.edit();
                        editor.putBoolean("SmartBrightness", true);
                        editor.apply();
                    }
                }else{
                    if(batteryLevel >= 70){
                        Settings.System.putInt(contentResolver, Settings.System.SCREEN_BRIGHTNESS, 85);
                    }else if(batteryLevel >= 50 && batteryLevel <= 69){
                        Settings.System.putInt(contentResolver, Settings.System.SCREEN_BRIGHTNESS, 70);
                    }else if(batteryLevel >= 20 && batteryLevel <= 49){
                        Settings.System.putInt(contentResolver, Settings.System.SCREEN_BRIGHTNESS, 50);
                    }else if(batteryLevel >= 10 && batteryLevel <= 19){
                        Settings.System.putInt(contentResolver, Settings.System.SCREEN_BRIGHTNESS, 30);
                    }else if(batteryLevel <= 9){
                        Settings.System.putInt(contentResolver, Settings.System.SCREEN_BRIGHTNESS, 10);
                    }
                    SharedPreferences.Editor editor = sharedPreferences.edit();
                    editor.putBoolean("SmartBrightness", true);
                    editor.apply();
                }
            }else{
                SharedPreferences.Editor editor = sharedPreferences.edit();
                editor.putBoolean("SmartBrightness", false);
                editor.apply();
            }
        }
    });

    return view;
}
private void requestWriteSettingsPermission(){
    if(Build.VERSION.SDK_INT >= 23){
        Intent intent = new Intent(android.provider.Settings.ACTION_MANAGE_WRITE_SETTINGS);
        intent.setData(Uri.parse("package:" + context.getPackageName()));
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        startActivity(intent);
    }
}
public void showMissingPermissionDialog(){
    final ViewGroup nullParent = null;
    AlertDialog.Builder alertDialog = new AlertDialog.Builder(getActivity());
    LayoutInflater layoutInflater = LayoutInflater.from(getActivity());
    View view = layoutInflater.inflate(R.layout.write_settings_explaination, nullParent);

    alertDialog.setView(view);
    alertDialog.setCancelable(false);
    alertDialog.setPositiveButton("Continue", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int which) {
            requestWriteSettingsPermission();
            dialog.dismiss();
        }
    });
    alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int which) {
            dialog.dismiss();
        }
    });
    alertDialog.show();
}
public boolean writeSettingsPermissionGranted(){
    if(Build.VERSION.SDK_INT >= 23){
        if(android.provider.Settings.System.canWrite(context)){
            return true;
        }
    }
    return false;
}

}

但問題是，當我在真實設備上測試時，即使我的設備電池電量高於50％

當我點擊按鈕時屏幕亮度變為10，這也意味着執行此代碼。

Settings.System.putInt(contentResolver, Settings.System.SCREEN_BRIGHTNESS, 10);

我不知道它為什么在廣播接收器中完美運行但不使用按鈕點擊。

如果有人有想法解決這個或遇到同樣的問題，請幫助我，提前謝謝。

Answer 1

如果您查看BatteryManager.EXTRA_LEVEL的文檔，您會看到它是

包含當前電池電量的整數字段，從0到EXTRA_SCALE。

EXTRA_SCALE是你可以抓住的另一個值，我在這里的假設以及你所面臨的問題是規模可能是1.0，這意味着20％的電池實際上是.20

要正確計算電池百分比，請在0 - > 100刻度上使用以下內容

batteryLevel = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, 0);
levelScale = intent.getIntExtra(BatteryManager.EXTRA_SCALE, 0);

double realPercent = (((double)batteryLevel) / levelScale) * 100 ;

編輯

我只是重新閱讀你的代碼，並且你看到0作為onClick方法的報告百分比並不奇怪，你寫道：

intent = new Intent();
batteryLevel = intent.getIntExtra(...);

在這里，您試圖從剛剛創建的intent中獲取數據，而不是實際包含您要查找的數據的數據。

嘗試將您的意圖改為實際獲得電池電量，然后使用我的上述修復來獲得適當的百分比。

Intent batteryIntent = registerReceiver(null, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));