1、activity_main.xml 两个按钮，一个open一个close

复制代码 代码如下:

<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>

2、MainActivity 核心代码

复制代码 代码如下:

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;

}

}

3、AndroidManifest.xml 加入摄像头和闪关灯的权限

复制代码 代码如下:

<"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" />

<>

<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" />

<>

<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>