Android 手电筒源码

最近由于公司需要，做了一个手电筒，其实手电筒原理很简单，就是调用照相机的闪光灯，控制闪光灯的开关，就可以实现手电筒的效果，

强调一下，代码中一定要注意在结束的时候对闪光灯进行释放，否则就会导致使用照相机的时候出现——无法连接到相机 这个问题

手电筒APK下载地址：点击打开下载链接

手电筒项目源码下载：点击打开下载链接

主要代码如下：

package com.techainsh.flashlight;

import java.util.List;
import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.os.PowerManager;
import android.os.Vibrator;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.view.KeyEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.Toast;

public class MainActivity extends Activity implements OnClickListener {

public ImageView btnimageView = null;
public RelativeLayout bgmageView = null;
private Camera camera;
private boolean isOpen = true;
public final static int OPEN_CAMERA = 1011;
public final static int OPEN_LIGHT = 1012;
public final static int CLOSE_LIGHT = 1013;
private Vibrator vibrator;
long[] pattern = { 100, 200 };
PowerManager.WakeLock wakeLock;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
handler.sendEmptyMessage(OPEN_CAMERA);
vibrator = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
btnimageView = (ImageView) findViewById(R.id.btn_image);
bgmageView = (RelativeLayout) findViewById(R.id.bg_image);
bgmageView.setBackgroundResource(R.drawable.bg_flashlight_off);
btnimageView.setImageResource(R.drawable.btn_flash_light_off);
btnimageView.setOnClickListener(this);
bgmageView.setBackgroundResource(R.drawable.bg_flashlight_on);
btnimageView.setImageResource(R.drawable.btn_flash_light_on);
handler.sendEmptyMessage(OPEN_LIGHT);
vibrator.vibrate(pattern, -1);

}

Handler handler = new Handler(Looper.getMainLooper()) {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case OPEN_CAMERA:
camera = Camera.open();
break;
case OPEN_LIGHT:
Parameters params = camera.getParameters();
List<String> list = params.getSupportedFlashModes();
if (list.contains(Parameters.FLASH_MODE_TORCH)) {
params.setFlashMode(Parameters.FLASH_MODE_TORCH);
} else {
Toast.makeText(getApplicationContext(), "此设备不支持闪光灯模式",
Toast.LENGTH_SHORT).show();
}
camera.setParameters(params);
camera.startPreview();
isOpen = true;
break;
case CLOSE_LIGHT:
if (isOpen) {
Parameters closepParameters = camera.getParameters();
closepParameters
.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);
camera.setParameters(closepParameters);
camera.stopPreview();
// camera.release();
isOpen = false;
// sendEmptyMessage(OPEN_CAMERA);
}
break;
default:
break;
}
}
};

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

public void onStop() {
super.onStop();
vibrator.cancel();
if (null != camera) {
camera.release();
camera = null;
}

MainActivity.this.finish();
}

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
QuitAlert();
}

return super.onKeyDown(keyCode, event);
}

public void QuitAlert() {
new AlertDialog.Builder(MainActivity.this).setTitle("关闭手电筒提示")
.setIcon(R.drawable.ic_launcher).setMessage("确定要关闭手电筒么？")
.setPositiveButton("确定", new DialogInterface.OnClickListener() {

public void onClick(DialogInterface dialog, int which) {
MainActivity.this.finish();

}
})
.setNegativeButton("取消", new DialogInterface.OnClickListener() {

@Override
public void onClick(DialogInterface arg0, int arg1) {
// TODO Auto-generated method stub

}
}).create().show();
}

@Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
PowerManager pm = (PowerManager) getSystemService(POWER_SERVICE);
wakeLock = pm.newWakeLock(PowerManager.SCREEN_BRIGHT_WAKE_LOCK
| PowerManager.ON_AFTER_RELEASE, "test");
wakeLock.acquire();
}

@Override
protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
if (wakeLock != null)
wakeLock.release();
}

@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.btn_image:
if (isOpen) {
bgmageView.setBackgroundResource(R.drawable.bg_flashlight_off);
btnimageView.setImageResource(R.drawable.btn_flash_light_off);
handler.sendEmptyMessage(CLOSE_LIGHT);
vibrator.vibrate(pattern, -1);
} else {
bgmageView.setBackgroundResource(R.drawable.bg_flashlight_on);
btnimageView.setImageResource(R.drawable.btn_flash_light_on);
handler.sendEmptyMessage(OPEN_LIGHT);
vibrator.vibrate(pattern, -1);
}
break;
default:
break;
}

}

}

需要用到的权限如下：

<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.FLASHLIGHT" />
<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.camera.autofocus" />
<uses-feature android:name="android.hardware.camera.flash" />
<uses-permission android:name="android.permission.VIBRATE" />
<uses-permission android:name="android.permission.WAKE_LOCK" />

界面布局如下：

<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:background="@drawable/bg_flashlight" >

<RelativeLayout
android:id="@+id/bg_image"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/bg_flashlight_off" >

<ImageView
android:id="@+id/btn_image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_alignParentBottom="true"
android:layout_marginBottom="100dip"
android:src="@drawable/btn_flash_light_on" />
</RelativeLayout>

</RelativeLayout>

实现的效果如下：