How to enable flashlight for Android

Copy codeThe Code is as follows: 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) // determine whether the device supports flashlight
{
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 (0 xffffffff );
}
}
}

Handlight. xml
Copy codeThe Code is as follows: <? 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>

Add Permissions
<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"/>
Note: not all devices support

There is also a saying on the Internet that the system hidden api is called, but I did not respond, it may be a problem with the system version, back up
Direct Control Using IHardwareService
Android1.5 previously provided this interface directly. Later, we need to do it ourselves.
Create a new Android. OS package in your project and create an IHardwareService. aidl file. The content is as follows:Copy codeThe Code is as follows: package android. OS;

/** {@ Hide }*/
Interface IHardwareService
{
// Obsolete flashlight support
Boolean getFlashlightEnabled ();
Void setFlashlightEnabled (boolean on );
}

Then introduce
Copy codeThe Code is as follows: import android. OS. IHardwareService;

/**
* Enable and disable the flashlight.
* @ 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 ();
}

}

In this way, you can turn on the flashlight. Permissions to be used:
Copy codeThe Code is as follows: <uses-permission android: name = "android. permission. FLASHLIGHT"/>
<Uses-permission android: name = "android. permission. HARDWARE_TEST"/>