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本篇文章主要介绍 Android
开发中的部分知识点,通过阅读本篇文章,您将收获以下内容:
一、获取系统Settings 中的亮度
二、修改APP界面屏幕亮度,不会影响其他APP
三、修改系统Settings 中屏幕亮度,影响所有APP
四、完整代码实现
系统屏幕亮度值在(0~255)
之间,获取方法很简单,只需要调用以下方法即可。
- /**
- * 1.获取系统默认屏幕亮度值 屏幕亮度值范围(0-255)
- * **/
- private int getScreenBrightness(Context context) {
- ContentResolver contentResolver = context.getContentResolver();
- int defVal = 125;
- return Settings.System.getInt(contentResolver,
- Settings.System.SCREEN_BRIGHTNESS, defVal);
- }
修改屏幕亮度包含两种:
1.修改APP界面屏幕亮度,不会影响其他APP
。
2.修改系统 Settings
中屏幕亮度,影响所有APP。
修改自身 APP
亮度很简单,只需要在Activity OnCreate
方法调用如下代码即可。
- /**
- * 2.设置 APP界面屏幕亮度值方法
- * **/
- private void setAppScreenBrightness(int birghtessValue) {
- Window window = getWindow();
- WindowManager.LayoutParams lp = window.getAttributes();
- lp.screenBrightness = birghtessValue / 255.0f;
- window.setAttributes(lp);
- }
修改系统 Settings
中的屏幕亮度,由于会影响到所有APP
,需要申请修改Settings
的权限<uses-permission * android:name="android.permission.WRITE_SETTINGS"/>
,同时需要取消光感自动调节屏幕亮度的功能,设置为手动调节模式,否则光感传感器会随着光照强度的变化修改系统屏幕亮度,并且非系统签名的APP
,需要用户手动授权后才可以修改背光亮度。
关闭光感,设置手动调节背光模式实现方法如下:
- /**
- * 3.关闭光感,设置手动调节背光模式
- *
- * SCREEN_BRIGHTNESS_MODE_AUTOMATIC 自动调节屏幕亮度模式值为1
- *
- * SCREEN_BRIGHTNESS_MODE_MANUAL 手动调节屏幕亮度模式值为0
- * **/
- public void setScreenManualMode(Context context) {
- ContentResolver contentResolver = context.getContentResolver();
- try {
- int mode = Settings.System.getInt(contentResolver,
- Settings.System.SCREEN_BRIGHTNESS_MODE);
- if (mode == Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC) {
- Settings.System.putInt(contentResolver,
- Settings.System.SCREEN_BRIGHTNESS_MODE,
- Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);
- }
- } catch (Settings.SettingNotFoundException e) {
- e.printStackTrace();
- }
- }
非系统签名应用,引导用户手动授权修改Settings 权限
非系统签名应用,无法直接修改Settings
,需要引导用户手动授权。
- /**
- * 4.非系统签名应用,引导用户手动授权修改Settings 权限
- * **/
- private static final int REQUEST_CODE_WRITE_SETTINGS = 1000;
-
- private void allowModifySettings() {
- // Settings.System.canWrite(MainActivity.this)
- // 检测是否拥有写入系统 Settings 的权限
- if (!Settings.System.canWrite(MainActivity.this)) {
- AlertDialog.Builder builder = new AlertDialog.Builder(this,
- android.R.style.Theme_Material_Light_Dialog_Alert);
- builder.setTitle("请开启修改屏幕亮度权限");
- builder.setMessage("请点击允许开启");
- // 拒绝, 无法修改
- builder.setNegativeButton("拒绝",
- new DialogInterface.OnClickListener() {
- @Override
- public void onClick(DialogInterface dialog, int which) {
- Toast.makeText(MainActivity.this,
- "您已拒绝修系统Setting的屏幕亮度权限", Toast.LENGTH_SHORT)
- .show();
- }
- });
- builder.setPositiveButton("去开启",
- new DialogInterface.OnClickListener() {
- @Override
- public void onClick(DialogInterface dialog, int which) {
- // 打开允许修改Setting 权限的界面
- Intent intent = new Intent(
- Settings.ACTION_MANAGE_WRITE_SETTINGS, Uri
- .parse("package:"
- + getPackageName()));
- startActivityForResult(intent,
- REQUEST_CODE_WRITE_SETTINGS);
- }
- });
- builder.setCancelable(false);
- builder.show();
- }
- }
-
- @Override
- protected void onActivityResult(int requestCode, int resultCode, Intent data) {
- // TODO Auto-generated method stub
- super.onActivityResult(requestCode, resultCode, data);
- if (requestCode == REQUEST_CODE_WRITE_SETTINGS) {
- if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
- // Settings.System.canWrite方法检测授权结果
- if (Settings.System.canWrite(getApplicationContext())) {
- // 5.调用修改Settings屏幕亮度的方法 屏幕亮度值 200
- ModifySettingsScreenBrightness(MainActivity.this, 200);
- Toast.makeText(this, "系统屏幕亮度值" + getScreenBrightness(this),
- Toast.LENGTH_SHORT).show();
- } else {
- Toast.makeText(MainActivity.this, "您已拒绝修系统Setting的屏幕亮度权限",
- Toast.LENGTH_SHORT).show();
- }
- }
- }
- }
修改Setting 中屏幕亮度值 实现
拥有系统签名的应用可以直接调用此方法修改系统屏幕亮度,非系统签名应用,只有用户授权后才可以修改。
- /**
- * 5.修改Setting 中屏幕亮度值
- *
- * 修改Setting的值需要动态申请权限 <uses-permission
- * android:name="android.permission.WRITE_SETTINGS"/>
- * **/
- private void ModifySettingsScreenBrightness(Context context,
- int birghtessValue) {
- // 首先需要设置为手动调节屏幕亮度模式
- setScreenManualMode(context);
-
- ContentResolver contentResolver = context.getContentResolver();
- Settings.System.putInt(contentResolver,
- Settings.System.SCREEN_BRIGHTNESS, birghtessValue);
- }
- public class MainActivity extends Activity {
-
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- //获取屏幕亮度
- getScreenBrightness(this);
- Toast.makeText(this, "系统屏幕亮度值" + getScreenBrightness(this),
- Toast.LENGTH_SHORT).show();
- // 设置APP 屏幕亮度后,系统Setting亮度将对此app 不生效
- setAppScreenBrightness(100);
- allowModifySettings();
- setContentView(R.layout.activity_main);
-
- }
-
- /**
- * 1.获取系统默认屏幕亮度值 屏幕亮度值范围(0-255)
- * **/
- private int getScreenBrightness(Context context) {
- ContentResolver contentResolver = context.getContentResolver();
- int defVal = 125;
- return Settings.System.getInt(contentResolver,
- Settings.System.SCREEN_BRIGHTNESS, defVal);
- }
-
- /**
- * 2.设置 APP界面屏幕亮度值方法
- * **/
- private void setAppScreenBrightness(int birghtessValue) {
- Window window = getWindow();
- WindowManager.LayoutParams lp = window.getAttributes();
- lp.screenBrightness = birghtessValue / 255.0f;
- window.setAttributes(lp);
- }
-
- /**
- * 3.关闭光感,设置手动调节背光模式
- *
- * SCREEN_BRIGHTNESS_MODE_AUTOMATIC 自动调节屏幕亮度模式值为1
- *
- * SCREEN_BRIGHTNESS_MODE_MANUAL 手动调节屏幕亮度模式值为0
- * **/
- public void setScreenManualMode(Context context) {
- ContentResolver contentResolver = context.getContentResolver();
- try {
- int mode = Settings.System.getInt(contentResolver,
- Settings.System.SCREEN_BRIGHTNESS_MODE);
- if (mode == Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC) {
- Settings.System.putInt(contentResolver,
- Settings.System.SCREEN_BRIGHTNESS_MODE,
- Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);
- }
- } catch (Settings.SettingNotFoundException e) {
- e.printStackTrace();
- }
- }
-
- /**
- * 4.非系统签名应用,引导用户手动授权修改Settings 权限
- * **/
- private static final int REQUEST_CODE_WRITE_SETTINGS = 1000;
-
- private void allowModifySettings() {
- // Settings.System.canWrite(MainActivity.this)
- // 检测是否拥有写入系统 Settings 的权限
- if (!Settings.System.canWrite(MainActivity.this)) {
- AlertDialog.Builder builder = new AlertDialog.Builder(this,
- android.R.style.Theme_Material_Light_Dialog_Alert);
- builder.setTitle("请开启修改屏幕亮度权限");
- builder.setMessage("请点击允许开启");
- // 拒绝, 无法修改
- builder.setNegativeButton("拒绝",
- new DialogInterface.OnClickListener() {
- @Override
- public void onClick(DialogInterface dialog, int which) {
- Toast.makeText(MainActivity.this,
- "您已拒绝修系统Setting的屏幕亮度权限", Toast.LENGTH_SHORT)
- .show();
- }
- });
- builder.setPositiveButton("去开启",
- new DialogInterface.OnClickListener() {
- @Override
- public void onClick(DialogInterface dialog, int which) {
- // 打开允许修改Setting 权限的界面
- Intent intent = new Intent(
- Settings.ACTION_MANAGE_WRITE_SETTINGS, Uri
- .parse("package:"
- + getPackageName()));
- startActivityForResult(intent,
- REQUEST_CODE_WRITE_SETTINGS);
- }
- });
- builder.setCancelable(false);
- builder.show();
- }
- }
-
- @Override
- protected void onActivityResult(int requestCode, int resultCode, Intent data) {
- // TODO Auto-generated method stub
- super.onActivityResult(requestCode, resultCode, data);
- if (requestCode == REQUEST_CODE_WRITE_SETTINGS) {
- if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
- // Settings.System.canWrite方法检测授权结果
- if (Settings.System.canWrite(getApplicationContext())) {
- // 5.调用修改Settings屏幕亮度的方法 屏幕亮度值 200
- ModifySettingsScreenBrightness(MainActivity.this, 200);
- Toast.makeText(this, "系统屏幕亮度值" + getScreenBrightness(this),
- Toast.LENGTH_SHORT).show();
- } else {
- Toast.makeText(MainActivity.this, "您已拒绝修系统Setting的屏幕亮度权限",
- Toast.LENGTH_SHORT).show();
- }
- }
- }
- }
-
- /**
- * 5.修改Setting 中屏幕亮度值
- *
- * 修改Setting的值需要动态申请权限 <uses-permission
- * android:name="android.permission.WRITE_SETTINGS"/>
- * **/
- private void ModifySettingsScreenBrightness(Context context,
- int birghtessValue) {
- // 首先需要设置为手动调节屏幕亮度模式
- setScreenManualMode(context);
-
- ContentResolver contentResolver = context.getContentResolver();
- Settings.System.putInt(contentResolver,
- Settings.System.SCREEN_BRIGHTNESS, birghtessValue);
- }
- }
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