Android 调整亮度

package com.android.brightness; import android.app.Activity; import android.content.ContentResolver; import android.net.Uri; import android.os.Bundle; import android.view.View; import android.view.WindowManager; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; public class MainActivity extends Activity implements OnClickListener{ /** Called when the activity is first created. */ private EditText mEditText; private Button mBtn; private int brighnessPro; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); mEditText = (EditText) findViewById(R.id.editText); mBtn = (Button) findViewById(R.id.btn_brightness); mBtn.setOnClickListener(this); } @Override public void onClick(View arg0) { brighnessPro = Integer.parseInt(mEditText.getText().toString().trim()); /** * 改变系统亮度的步骤，brighnessPro是亮度值 */ ContentResolver resolver = getContentResolver(); setBrightnesss(brighnessPro); saveBrightness(resolver, brighnessPro); } public void setBrightnesss(int brightness) { WindowManager.LayoutParams lp = getWindow().getAttributes(); if (brightness <= 1) { return; } else { lp.screenBrightness = brightness / 255.0f; getWindow().setAttributes(lp); } } public static void saveBrightness(ContentResolver resolver, int brightness) { Uri uri = android.provider.Settings.System .getUriFor("screen_brightness"); android.provider.Settings.System.putInt(resolver, "screen_brightness", brightness); resolver.notifyChange(uri, null); } }