android 手电筒

package com.example.flashlight;

import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.os.Bundle;
import android.os.Handler;
import android.app.Activity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {

private boolean isopent = false;
private Camera camera;
private Button button;
boolean is = true;
boolean sosflag = true;
Button sos;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
View view = View.inflate(this, R.layout.main, null);
setContentView(view);
button = (Button) findViewById(R.id.main_img);
//手电筒开关按钮
button.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
is=false;
try{
if (!isopent) {
on();
} else {
off();
}
}catch(Exception e){
e.printStackTrace();
}
}
});
//sos按钮
sos = (Button)findViewById(R.id.sos);
sos.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
if(sosflag){
//开启线程
handler.removeCallbacks(runnable);
handler.postDelayed(runnable,1000);
sosflag=false;
}else{
//关闭线程
handler.removeCallbacks(runnable);
}
}
});

}
//sos线程
private Handler handler = new Handler();
private Runnable runnable = new Runnable() {
public void run () {
on();
delay(500);
off();
handler.postDelayed(this,1000);
}
};

/**
* 延时函数
* @param ms
*/
private void delay(int ms){
try {
Thread.currentThread();
Thread.sleep(ms);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
/*
* 打开手电筒
* */
public void on(){
button.setBackgroundResource(R.drawable.on);
// Toast.makeText(getApplicationContext(), "您已经打开了手电筒", 0).show();
camera = Camera.open();
Parameters params = camera.getParameters();
params.setFlashMode(Parameters.FLASH_MODE_TORCH);
camera.setParameters(params);
camera.startPreview(); // 开始亮灯
isopent = true;
}
//关闭手电筒
public void off(){
button.setBackgroundResource(R.drawable.off);
// Toast.makeText(getApplicationContext(), "关闭了手电筒", Toast.LENGTH_SHORT).show();
camera.stopPreview(); // 关掉亮灯
camera.release(); // 关掉照相机
isopent = false;
}
}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >
 
    <Button
        android:id="@+id/main_img"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:background="@drawable/off"
        >
    </Button>

    <Button
        android:id="@+id/sos"
        android:layout_width="50dip"
        android:layout_height="40dip"
        android:textSize="15sp"
        android:layout_alignBaseline="@+id/main_img"
        android:layout_alignBottom="@+id/main_img"
        android:layout_centerHorizontal="true"
        android:text="@string/sos" />
 
</RelativeLayout>

<!-- 摄像头、手电筒 -->
<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" />