Android 开启闪光灯做手电筒

public class HandLightActivity extends Activity implements OnClickListener{

private ToggleButton toggleButton;

private Camera m_Camera;

@Override

protected void onCreate(Bundle savedInstanceState) {

// TODO Auto-generated method stub

super.onCreate(savedInstanceState);

setContentView(R.layout.handlight);

toggleButton = (ToggleButton)this.findViewById(R.id.toggleButton1);

toggleButton.setOnClickListener(this);

getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

}

@Override

public void onClick(View v) {

ToggleButton tb = (ToggleButton)v;

if(!tb.isChecked()){

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

{

if ( null == m_Camera )

{

m_Camera = Camera.open();

}

Camera.Parameters parameters = m_Camera.getParameters();

parameters.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);

m_Camera.setParameters( parameters );

m_Camera.startPreview();

toggleButton.setBackgroundColor(0x30ffffff);

}

}

}else{

if ( m_Camera != null )

{

m_Camera.stopPreview();

m_Camera.release();

m_Camera = null;

}

toggleButton.setBackgroundColor(0xffffffff);

}

}

}

handlight.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:orientation="vertical" >

<ToggleButton android:id="@+id/toggleButton1"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:checked="true"

android:text="ToggleButton"/>

</LinearLayout>

需要加上权限

<uses-permission android:name="android.permission.FLASHLIGHT"/>

<uses-permission android:name="android.permission.WAKE_LOCK"/>

<uses-permission android:name="android.permission.CAMERA"/>

<uses-permission android:name="android.hardware.camera"/>

注意：并不是所有的设备都支持

网上还有一种说法是调用系统隐藏api，不过我试了没反应，可能是系统版本问题，备份一下

用IHardwareService直接控制

Android1.5以前是直接提供这个接口的，之后呢，需要我们自己来做一下。

在你的项目中新建一个包Android.os,新建一个IHardwareService.aidl文件，内容如下：

package android.os;

/** {@hide} */
interface IHardwareService
{
// obsolete flashlight support
boolean getFlashlightEnabled();
void setFlashlightEnabled(boolean on);
}

然后在你的程序中引入

import android.os.IHardwareService;

/**
* 设置闪光灯的开启和关闭
* @param isEnable
* @author linc
* @date 2012-3-18
*/
private void setFlashlightEnabled(boolean isEnable)
{
try
{
Method method = Class.forName("android.os.ServiceManager").getMethod("getService", String.class);
IBinder binder = (IBinder) method.invoke(null, new Object[] { "hardware" });

IHardwareService localhardwareservice = IHardwareService.Stub.asInterface(binder);
localhardwareservice.setFlashlightEnabled(isEnable);
}
catch (Exception e)
{
e.printStackTrace();
}

}

这样就可以开启闪光灯了。要使用的权限：

<uses-permission android:name="android.permission.FLASHLIGHT" />
<uses-permission android:name="android.permission.HARDWARE_TEST" />