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2017年5月30日 星期二

Android權限 ─ 調整螢幕亮度、特殊權限 android.permission.WRITE_SETTINGS

 前言:

之前調整權限的方式請看這裡
這次調用權限的方式比較不一樣。看圖吧!




權限使用:

請參考這篇:
https://yanlu.me/android-m6-0-permission-chasm/
以下全部複製。
這是WRITE_SETTINGS權限的使用方式。
記得先在manifest內增加權限

<uses-permission android:name="android.permission.WRITE_SETTINGS"/>
 


/**
 * An app can use this method to check if it is currently allowed to write or modify system
 * settings. In order to gain write access to the system settings, an app must declare the
 * {@link android.Manifest.permission#WRITE_SETTINGS} permission in its manifest. If it is
 * currently disallowed, it can prompt the user to grant it this capability through a
 * management UI by sending an Intent with action
 * {@link android.provider.Settings#ACTION_MANAGE_WRITE_SETTINGS}.
 *
 * @param context A context
 * @return true if the calling app can write to system settings, false otherwise
 */
 if(!Settings.System.canWrite(this)){
      Intent intent = new Intent(Settings.ACTION_MANAGE_WRITE_SETTINGS,
                Uri.parse("package:" + getPackageName()));
      startActivityForResult(intent, REQUEST_CODE);
 } 
 
 
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == REQUEST_CODE) {
        if (Settings.System.canWrite(this)) {
            //检查返回结果
            Toast.makeText(MainActivity.this, "WRITE_SETTINGS permission granted", Toast.LENGTH_SHORT).show();
        } else {
            Toast.makeText(MainActivity.this, "WRITE_SETTINGS permission not granted", Toast.LENGTH_SHORT).show();
        }
    }
}
 
其中比較需要注意的地方是Settings.System.canWrite這方法在太低版本的Android上面不適用。
調用會Crash。
所以我們稍加做了一些判斷。

 
if (Build.VERSION.SDK_INT > Build.VERSION_CODES.M) {//android6.0以上使用需要權限
                    if (!Settings.System.canWrite(context)) {//沒有給予權限的話Do Something
                        //跳轉畫面到權限頁面給使用者勾選
                        Intent intent = new Intent(Settings.ACTION_MANAGE_WRITE_SETTINGS,
                                Uri.parse("package:" + getPackageName()));
                        startActivityForResult(intent, 9487);
                    } else {//已有權限 Do Something
                        start_bRight();//開始調整螢幕
                    }

                } else {//android6.0以下可直接調用
                    start_bRight();//開始調整螢幕
                }

 @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        switch (requestCode) {
            case 9487:
                if (Build.VERSION.SDK_INT > Build.VERSION_CODES.M) {
                    if (Settings.System.canWrite(this)) {
                        start_bRight();//開始調整螢幕
                    } else {
                        Toast.makeText(MainActivity.this, "請給予權限。", Toast.LENGTH_SHORT).show();
                    }
                } else {
                    start_bRight();//開始調整螢幕
                }
                break;
        }
    }

使用
Build.VERSION.SDK_INT > Build.VERSION_CODES.M
來判斷是否Android的版本為SDK 23以上,如果是23以下就沒有權限問題,也可以順利調用Settings.System.canWrite方法。




調整亮度Code:

裡面帶有SeekBar參數。

    //調整螢幕亮度
    private void start_bRight() {

        //設定最大值
        SeekBar m_SeekBar = (SeekBar) findViewById(R.id.see_bar);
        m_SeekBar.setMax(255);

        //取得目前系統的亮度值
        int brightness = android.provider.Settings.System.getInt(getContentResolver(), android.provider.Settings.System.SCREEN_BRIGHTNESS, 255);
        Log.w(TAG, "亮度 素質" + brightness);

        //將亮度值 射定道系統中
        m_SeekBar.setProgress(brightness);

        //關閉自動調整亮度功能
        Settings.System.putInt(this.getContentResolver(), Settings.System.SCREEN_BRIGHTNESS_MODE, Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);
        /*
         * @param cr要訪問的ContentResolver。
         * @param name要修改的設置的名稱。
         * @param value設置的新值。
         */


        //設定SeeBar的監聽事件
        m_SeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                //觀察目前系統的亮度值
                int brightness = android.provider.Settings.System.getInt(getContentResolver(), android.provider.Settings.System.SCREEN_BRIGHTNESS, 255);
                Log.w(TAG, "觀察亮度 素質" + brightness);

                //針對App端的UI作為 螢幕亮度調整
                // (假設App端調整最暗,)
                Window localWindow = getWindow();
                WindowManager.LayoutParams localLayoutParams = localWindow.getAttributes();
                localLayoutParams.screenBrightness = progress / 255.0f;
                localWindow.setAttributes(localLayoutParams);

                //如果想改變整個系統的亮度
                //方法1:
//                Uri uri = android.provider.Settings.System.getUriFor("screen_brightness");
//                android.provider.Settings.System.putInt(context.getContentResolver(), getContentResolver(), progress);
//                context.getContentResolver().notifyChange(uri, null);

                //方法2:
                android.provider.Settings.System.putInt(getContentResolver(), android.provider.Settings.System.SCREEN_BRIGHTNESS, progress);

                /*補充:android.provider.Settings.System.putInt(參數1,參數2,參數3);
                *
                *參數1:需要一個ContentResolver ,所以getContentResolver()
                *參數2:其實就是一個字串,"screen_brightness",但是這個類別中已經有final String 位置在→ android.provider.Settings.System.SCREEN_BRIGHTNESS
                *參數3:設定的值
                *
                * */
            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {

            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {

            }
        });

    }
 
這裡還有另外一些調整亮度的方式。
如果你要進入畫面直接最亮可以嘗試以下方法
【Android開發經驗】與屏幕亮度調節相關的各種方法整理
public class SystemManager {  
  
    private Context mContext;  
    private static SystemManager sInstance;  
  
    private SystemManager(final Context context) {  
        mContext = context;  
    }  
  
    public static SystemManager init(final Context context) {  
        if (null == sInstance) {  
            sInstance = new SystemManager(context);  
        }  
        return sInstance;  
    }  
  
    public static SystemManager getInstance() {  
        return sInstance;  
    }  
  
    // 判斷是否是自動調光模式  
    public boolean isAutoBrightness() {  
        boolean automicBrightness = false;  
        try {  
            ContentResolver resolver = mContext.getContentResolver();  
            automicBrightness = Settings.System.getInt(resolver,  
                    Settings.System.SCREEN_BRIGHTNESS_MODE) == Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC;  
        } catch (SettingNotFoundException e) {  
            e.printStackTrace();  
        }  
        return automicBrightness;  
    }  
  
    // 設置屏幕亮度  
    public void setBrightness(Activity activity, int brightness) {  
        WindowManager.LayoutParams lp = activity.getWindow().getAttributes();  
        lp.screenBrightness = Float.valueOf(brightness) * (1f / 255f);  
        activity.getWindow().setAttributes(lp);  
    }  
  
    // 保存屏幕亮度  
    public void saveBrightness(int brightness) {  
        ContentResolver resolver = mContext.getContentResolver();  
        Uri uri = android.provider.Settings.System  
                .getUriFor("screen_brightness");  
        android.provider.Settings.System.putInt(resolver, "screen_brightness",  
                brightness);  
        resolver.notifyChange(uri, null);  
    }  
  
    // 開啟自動調光模式  
    public void startAutoBrightness() {  
        ContentResolver resolver = mContext.getContentResolver();  
        Settings.System.putInt(resolver,  
                Settings.System.SCREEN_BRIGHTNESS_MODE,  
                Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC);  
        Uri uri = android.provider.Settings.System  
                .getUriFor("screen_brightness");  
        resolver.notifyChange(uri, null);  
    }  
  
    // 關閉自動調光模式  
    public void stopAutoBrightness() {  
        ContentResolver resolver = mContext.getContentResolver();  
        Settings.System.putInt(resolver,  
                Settings.System.SCREEN_BRIGHTNESS_MODE,  
                Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);  
        Uri uri = android.provider.Settings.System  
                .getUriFor("screen_brightness");  
        resolver.notifyChange(uri, null);  
    }  
  
    // 獲得當前屏幕亮度  
    public int getScreenBrightness() {  
        int nowBrightnessValue = 0;  
        try {  
            ContentResolver resolver = mContext.getContentResolver();  
            nowBrightnessValue = android.provider.Settings.System.getInt(  
                    resolver, Settings.System.SCREEN_BRIGHTNESS);  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
        return nowBrightnessValue;  
    }  
  
    // 設置光亮模式  
    public void setBrightnessMode(int mode) {  
        Settings.System.putInt(mContext.getContentResolver(),  
                Settings.System.SCREEN_BRIGHTNESS_MODE, mode);  
    }  
  
    // 獲得亮度模式  
    public int getBrightnessMode() {  
        try {  
            return Settings.System.getInt(mContext.getContentResolver(),  
                    Settings.System.SCREEN_BRIGHTNESS_MODE);  
        } catch (SettingNotFoundException e) {  
            return Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC;  
        }  
    }  
    //調到最亮 0~255 最暗~最亮
    Settings.System.putInt(getContentResolver(), Settings.System.SCREEN_BRIGHTNESS, 255);
  
}  
 




Demo:
https://dl.dropboxusercontent.com/s/hcv9hqoaudd8wuk/ScreenBright.7z

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