Android Combat Simple Tutorial-the 57th gun (share millet flashlight Source)

Flashlight function is simple and practical, the following we will study how to make a flashlight small program, beginners can learn the principle through an example, improve the enthusiasm and motivation to learn Android technology.

First, let's look at what Android permissions the flashlight will invoke:

  <!--open CAMERA permissions--    <uses-permission android:name= "Android.permission.CAMERA"/>    < Uses-feature android:name= "Android.hardware.camera"/>    <uses-feature android:name= " Android.hardware.autofocus "/>    <!--turn on flash rights--    <uses-permission android:name=" Android.permission.FLASHLIGHT "/>    <uses-permission android:name=" Android.permission.DISABLE_KEYGUARD "/ >    

The above three is the camera permissions, the following two is the Flash permission, in this example to be configured.

Here's a look at Mainactivity.java:

Package Com.zxx1.light;import Android.app.activity;import Android.hardware.camera;import Android.hardware.camera.parameters;import Android.os.bundle;import Android.view.keyevent;import Android.view.View ; Import Android.view.view.onclicklistener;import Android.view.window;import Android.view.windowmanager;import Android.widget.button;import Android.widget.toast;public class Lightactivity extends Activity {private Button lightbtn = null;private Camera camera = null;private Parameters Parameters = null;public static Boolean islight = true; Define switch state, status false, open state, status true, off state private int back = 0;//@Overridepublic void onCreate (Bundle savedinstancestate) { Super.oncreate (savedinstancestate);//Fullscreen settings, hidden window all decorations GetWindow (). SetFlags (WindowManager.LayoutParams.FLAG_ Fullscreen, WindowManager.LayoutParams.FLAG_FULLSCREEN); Requestwindowfeature (Window.feature_no_title); Settings screen display Untitled, must be started to set up, otherwise it can not be set GetWindow (). SetFlags (WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD, WindowManager.LayoutParams.FLAG_dismiss_keyguard); GetWindow (). SetFlags (WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON, WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);//Keep the screen solid Setcontentview (r.layout.main); lightbtn = (Button) Findviewbyid (r.id.btn_light); Lightbtn.setonclicklistener (new Onclicklistenerimpl ()); Class Onclicklistenerimpl implements Onclicklistener {@Overridepublic void OnClick (View v) {if (islight) { Lightbtn.setbackgroundresource (r.drawable.shou_on);//Set different picture Camera = Camera.open ();//turn on flash parameters = Camera.getparameters ();p Arameters.setflashmode (parameters.flash_mode_torch);//Open Camera.setparameters ( parameters); Camera.startpreview ();//Turn on islight = false;} else {lightbtn.setbackgroundresource (r.drawable.shou_off);p Arameters.setflashmode (Parameters.flash_mode_off);// Close camera.setparameters (parameters); Camera.stoppreview (); islight = True;camera.release ();}}} @Overrideprotected void OnDestroy () {camera.release (); Super.ondestroy ();} @Overridepublic boolean onKeyDown (int keycode, keyevent event) {if (keycode == Keyevent.keycode_back) {Back++;switch (back) {case 1:toast.maketext (lightactivity.this, getString (r.string.again_ Exit), Toast.length_short). Show (); Break;case 2:back = 0;dulback (); break;} return true;} else {return Super.onkeydown (KeyCode, event);}} public void Dulback () {///Close Program if (islight) {//Switch off when LightActivity.this.finish (); Android.os.Process.killProcess ( Android.os.Process.myPid ());//Close process} else if (!islight) {//switch on camera.release (); LightActivity.this.finish (); Android.os.Process.killProcess (Android.os.Process.myPid ());//close Process Islight = true;//Avoid , open the switch after exiting the program, again into the do not open the switch to exit directly when the program error}}}

The layout file is as follows:

<?xml version= "1.0" encoding= "Utf-8"? ><relativelayout xmlns:android= "http://schemas.android.com/apk/res/ Android "    android:id=" @+id/relativelayout "    android:layout_width=" wrap_content "    android:layout_ height= "Wrap_content" >    <button        android:id= "@+id/btn_light" android:layout_width= "Wrap_        Content "        android:layout_height=" wrap_content "        android:layout_centerhorizontal=" true "        Android: Layout_centervertical= "true"        android:background= "@drawable/shou_off"/></relativelayout>

Finally, do not forget to configure permissions, the last running instance is as follows:

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Android Combat Simple tutorial-57th gun (share Millet flashlight source)