应用中读取、设置屏幕亮度

package com.catcher.testcompass;import android.app.Activity;import android.os.Bundle;import android.provider.Settings;import android.provider.Settings.SettingNotFoundException;import android.provider.Settings.System;import android.view.View;import android.widget.EditText;import android.widget.Toast;public class ThreeActivity extends Activity {    private EditText etBrightness;        @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_third);        etBrightness = (EditText) findViewById(R.id.editText1);    }        public void getBrightness(View view){        Toast.makeText(this, "亮度="+getScreenBrightness(), Toast.LENGTH_SHORT).show();    }        public void setBrightness(View view){        int brightness=Integer.parseInt(etBrightness.getText().toString());        if (brightness>255) {            etBrightness.setError("不能超过255");            return;        }        setScreenBrightness(brightness);    }        public void setScreenBrightness(int brightness){        //如果是自动调整亮度则先换成手动调整再设置亮度        try {            if (Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC==Settings.System.getInt(getContentResolver(), System.SCREEN_BRIGHTNESS_MODE)) {                Settings.System.putInt(getContentResolver(), System.SCREEN_BRIGHTNESS_MODE,System.SCREEN_BRIGHTNESS_MODE_MANUAL);            }        } catch (SettingNotFoundException e) {            e.printStackTrace();        }        Settings.System.putInt(getContentResolver(), System.SCREEN_BRIGHTNESS, brightness);    }        public int getScreenBrightness(){        int brightness=-1;        try {            brightness=Settings.System.getInt(getContentResolver(), System.SCREEN_BRIGHTNESS);        } catch (SettingNotFoundException e) {            e.printStackTrace();        }        return brightness;    }}

AndroidManifest.xml还需要添加权限

布局文件

其中 android:keepScreenOn="true" 可以保持屏幕常量。