Android手电筒兼容各个手机与版本

在写手电筒APP之前,当然已经参考market上的很多手电筒APP,还有网上如何实现手电筒功能的各种源码。不管是源码还是market上的APP,总结了几点的问题。

1.我下载market上的所有手电筒APP都是通过Camera打开闪光灯的方式来实现的,但是大部分APP在打开Camera时没有进行异常处理工作,也没有任何的提示,如果当其他的程序在使用Camera时,并且返回或点Home后没有释放Camera,这时在启动相应的手电筒APP就会出现崩溃或者手电筒功能已经失效,这种用户体验用户是不能接受的!

2,网上很多Camera打开闪光灯实现手电筒的源码,而且原理都是一样的,当然这些代码并没有错误,但存在的问题是这些源码在有的手机版本上能够实现相应的功能,在另外的手机版本上就不起作用了,在CSDN资源中的大部分手电筒Demo也都会存在此问题,兼容性不好!

 

我自己实现的这个手电筒很简单,没有任何的UI界面,进入APP后就直接照明,实现的原理就2点:

1.跟其他手电筒APP一样,用Camera打开闪光灯开始照明

2.将当前屏幕的背光调节为最亮状态,退出时在恢复之前的背光值

代码和布局如下:

MainActivity.java

package huahua.flashlight;

import java.io.IOException;

import android.app.Activity;
import android.content.ContentResolver;
import android.content.pm.FeatureInfo;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.os.Bundle;
import android.provider.Settings;
import android.provider.Settings.SettingNotFoundException;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Toast;

/**
 *  花花手电筒
 * @author huahua
 */
public class MainActivity extends Activity implements SurfaceHolder.Callback{
	private static final String TAG = "huahua";      
	/**
	 * 进入APP时的背光亮度值
	 */
	int normal;
	/**
	 * 进入APP时,是否为自动调节亮度状态
	 */
	boolean AutoBrightnessOpen = false;
	
	private Camera camera; 
	
	private SurfaceView surfaceView;    
	private SurfaceHolder surfaceHolder;      
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		
		//去除title   
       this.requestWindowFeature(Window.FEATURE_NO_TITLE);  
		         
        //去掉Activity上面的状态栏   
       getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,  
        WindowManager.LayoutParams.FLAG_FULLSCREEN); 

		setContentView(R.layout.activity_main);
		
		surfaceView = (SurfaceView) this.findViewById(R.id.surfaceview);      
		surfaceHolder = surfaceView.getHolder();      
		surfaceHolder.addCallback(this);      
		surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);     
		
		if(isAutoBrightness(getContentResolver()))
		{
			AutoBrightnessOpen = true;
		}
		
		normal = Settings.System.getInt(getContentResolver(),  
		        Settings.System.SCREEN_BRIGHTNESS, 255); 
		
		PackageManager pm= this.getPackageManager();
		 FeatureInfo[]  features=pm.getSystemAvailableFeatures();
		 for(FeatureInfo f : features)
		 {
		   if(PackageManager.FEATURE_CAMERA_FLASH.equals(f.name))   //判断设备是否支持闪光灯
		   {
			   Log.d("huahua","支持闪光灯");
		   }
		 }
		 
	}
	@Override
	protected void onPause() {
		// TODO Auto-generated method stub
		super.onPause();
		
        Closeshoudian();
	}
	
	@Override
	protected void onResume() {
		// TODO Auto-generated method stub
		super.onResume();
		
		Openshoudian();
	}
	
	/**
     * 判断是否开启了自动亮度调节
     * 
    * @param aContext
     * @return
     */
    public boolean isAutoBrightness(ContentResolver aContentResolver) {
        boolean automicBrightness = false;
        try {
            automicBrightness = Settings.System.getInt(aContentResolver,
                    Settings.System.SCREEN_BRIGHTNESS_MODE) == Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC;
        } catch (SettingNotFoundException e) {
            e.printStackTrace();
        }
        return automicBrightness;
    }
    
    /**
     * 停止自动亮度调节
     * 
    * @param activity
     */
    public void stopAutoBrightness(Activity activity) {
        Settings.System.putInt(activity.getContentResolver(),
                Settings.System.SCREEN_BRIGHTNESS_MODE,
                Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);
    }
    
    /**
     * 恢复自动亮度调节
     * 
    * @param activity
     */
    public void setAutoBrightness(Activity activity) {
        Settings.System.putInt(activity.getContentResolver(),
                Settings.System.SCREEN_BRIGHTNESS_MODE,
                Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC);
    }
    
    /**
     * 打开手电筒
     */
    public void Openshoudian()
    {
    	//异常处理一定要加,否则Camera打开失败的话程序会崩溃
		try {
	        Log.d("huahua","camera打开");
			camera = Camera.open(); 
		} catch (Exception e) {
			Log.d("huahua","Camera打开有问题");
			Toast.makeText(MainActivity.this, "Camera被占用,请先关闭", Toast.LENGTH_SHORT).show();
		}
		
		if(camera != null)
		{
			//打开闪光灯
			 camera.startPreview();    
			 Camera.Parameters parameter = camera.getParameters();  
			 parameter.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH); 
			 camera.setParameters(parameter);
			 Log.d("huahua","闪光灯打开");
			 
			 //先关闭自动调节背光功能,才可以调节背光
			 if(AutoBrightnessOpen)
			 {
				stopAutoBrightness(MainActivity.this);
			 }
			 
			//将背光设置为最亮
	        WindowManager.LayoutParams lp = getWindow().getAttributes();
	        lp.screenBrightness = Float.valueOf(255) * (1f / 255f);
	        getWindow().setAttributes(lp);
		}
    }
    
    /**
     * 关闭手电筒
     */
    public void Closeshoudian()
    {
        if (camera != null)
        {
        	//关闭闪光灯
        	Log.d("huahua", "closeCamera()");
			camera.getParameters().setFlashMode(Camera.Parameters.FLASH_MODE_OFF); 
			camera.setParameters(camera.getParameters());
	        camera.stopPreview();
	        camera.release();
	        camera = null;
	        
	        //恢复进入程序前的背光值
	        WindowManager.LayoutParams lp = getWindow().getAttributes();
	        lp.screenBrightness = Float.valueOf(normal) * (1f / 255f);
	        getWindow().setAttributes(lp);
	        
	        //如果进入APP时背光为自动调节,则退出时需要恢复为自动调节状态
			 if(AutoBrightnessOpen)
			 {
				 setAutoBrightness(MainActivity.this);
			 }
        }
    }
    
	@Override
	public void surfaceChanged(SurfaceHolder holder, int format, int width,
			int height) {
		// TODO Auto-generated method stub
		
	}
	@Override
	public void surfaceCreated(SurfaceHolder holder) {
		try {        
			if(camera != null)
			{
			camera.setPreviewDisplay(holder);      
			}
		} catch (IOException e) {        
			e.printStackTrace();      
		}  
		
	}
	
	@Override
	public void surfaceDestroyed(SurfaceHolder holder) {
		// TODO Auto-generated method stub
		
	}


}


activity_main.xmlactivity_main.xml

<LinearLayout 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:orientation="vertical"
    tools:context=".MainActivity" >
    
   	<SurfaceView
	android:id="@+id/surfaceview"
	android:layout_width="match_parent"
	android:layout_height="match_parent" 
	android:background="#FFFFFF"/>

</LinearLayout>

 

好了,有兴趣的朋友可以下载源码,代码中都已加入了详细的注释

如果下载后调试发现运行不正常,可以反馈一起交流

源码下载地址

Android手电筒兼容各个手机与版本,,5-wow.com

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