android闪关灯的开启和关闭方法代码实例

<relativelayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingbottom="@dimen/activity_vertical_margin"
    android:paddingleft="@dimen/activity_horizontal_margin"
    android:paddingright="@dimen/activity_horizontal_margin"
    android:paddingtop="@dimen/activity_vertical_margin"
    tools:context=".mainactivity" >

    <textview
        android:id="@+id/textview1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

    <button
        android:id="@+id/button_open"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignleft="@+id/textview1"
        android:layout_below="@+id/textview1"
        android:layout_margintop="38dp"
        android:text="open" />

    <button
        android:id="@+id/button_close"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignleft="@+id/button_open"
        android:layout_below="@+id/button_open"
        android:layout_margintop="50dp"
        android:text="close" />

</relativelayout>

package com.qiantu.flashlight;

import android.app.activity;
import android.hardware.camera;
import android.hardware.camera.parameters;
import android.os.bundle;
import android.view.menu;
import android.view.view;
import android.view.view.onclicklistener;
import android.widget.button;

public class mainactivity extends activity {
 private camera camera;
 private button openbtn;
 private button closebtn;

 @override
 protected void oncreate(bundle savedinstancestate) {
  super.oncreate(savedinstancestate);
  setcontentview(r.layout.activity_main);

  openbtn = (button) findviewbyid(r.id.button_open);
  openbtn.setonclicklistener(new onclicklistener() {
   @override
   public void onclick(view v) {
    if (null != camera) {
     parameters parameters = camera.getparameters();
     parameters.setflashmode(parameters.flash_mode_torch);
     camera.setparameters(parameters);
    }
   }
  });

  closebtn = (button) findviewbyid(r.id.button_close);
  closebtn.setonclicklistener(new onclicklistener() {
   @override
   public void onclick(view v) {
    if (null != camera) {
     parameters parameters = camera.getparameters();
     parameters.setflashmode(parameters.flash_mode_off);
     camera.setparameters(parameters);
    }
   }
  });
 }

 @override
 protected void onstart() {
  super.onstart();
  camera = camera.open();
 }

 @override
 protected void ondestroy() {
  super.ondestroy();
  if (null != camera) {
   camera.release();
  }
 }

 @override
 public boolean oncreateoptionsmenu(menu menu) {
  getmenuinflater().inflate(r.menu.main, menu);
  return true;
 }

}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.qiantu.flashlight"
    android:versioncode="1"
    android:versionname="1.0" >

    <uses-sdk
        android:minsdkversion="8"
        android:targetsdkversion="18" />
   
    <!-- 添加的部分 -->
    <uses-feature android:name="android.hardware.camera" />
 <uses-feature android:name="android.hardware.autofocus" />
    <uses-permission android:name="android.permission.camera" />
 <uses-permission android:name="android.permission.flashlight" />
 <uses-permission android:name="android.permission.disable_keyguard" />
 <!-- end -->

    <application
        android:allowbackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/apptheme" >
        <activity
            android:name="com.qiantu.flashlight.mainactivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.main" />

                <category android:name="android.intent.category.launcher" />
            </intent-filter>
        </activity>
    </application>

</manifest>