Android 通用型手电筒代码

前几天这边一个小区断电，黑麻麻的，一只猫闯进寝室，把我吓哭，然后就果断写了个手电筒，下次断电，再来，我要吓死它。

我之前看到很多人都是直接调用闪光灯，其实大部分机型都不支持，我这个是用相机功能来实现的，大部分机型都支持。

mainactivity.class

public class mainactivity extends fragmentactivity {
 
  @override
  protected void oncreate(bundle savedinstancestate) {
    super.oncreate(savedinstancestate);
    setcontentview(r.layout.activity_main);
 
    if (isflashsupported()) {
      if (savedinstancestate == null) {
        getsupportfragmentmanager().begintransaction().add(r.id.container, new flashlightfragment()).commit();
      }
    } else {
      shownoflashalert();
    }
  }
 
  private void shownoflashalert() {
    new alertdialog.builder(this)
        .setmessage(r.string.device_not_support_msg)
        .seticon(android.r.drawable.ic_dialog_alert).settitle(r.string.device_not_support_title)
        .setpositivebutton(r.string.ok, new dialoginterface.onclicklistener() {
 
          @override
          public void onclick(dialoginterface dialog, int which) {
            dialog.dismiss();
            finish();
          }
        }).create().show();
  }
 
  private boolean isflashsupported() {
    packagemanager pm = getpackagemanager();
    return pm.hassystemfeature(packagemanager.feature_camera_flash);
  }
 
  public static class flashlightfragment extends fragment implements surfaceholder.callback {
 
    public flashlightfragment() { }
 
    imagebutton btnswitch;
    imageview bg;
    private boolean islighon = false;
 
    private camera camera;
    camera.parameters params;
 
    @override
    public void onstart() {
      super.onstart();
      surfaceview preview = (surfaceview) getview().findviewbyid(r.id.preview);
      surfaceholder mholder = preview.getholder();
      mholder.addcallback(this);
    }
 
    @override
    public void onpause() {
      super.onpause();
      turnoffflash();
    }
 
    @override
    public view oncreateview(layoutinflater inflater, viewgroup container, bundle savedinstancestate) {
      view view = inflater.inflate(r.layout.fragment_main_activity, container, false);
 
      // flash switch button
      btnswitch = (imagebutton) view.findviewbyid(r.id.flashlight_button);
 
      bg = (imageview) view.findviewbyid(r.id.flashlight_bg);
 
      // displaying button image
      togglebgimage();
 
      // switch button click event to toggle flash on/off
      btnswitch.setonclicklistener(new view.onclicklistener() {
 
        @override
        public void onclick(view v) {
          if (islighon) {
            turnoffflash();
          } else {
            turnonflash();
          }
        }
      });
 
      return view;
    }
 
    // turning on flash
    private void turnonflash() {
 
      if (!islighon) {
        if (camera == null || params == null) {
          return;
        }
        params = camera.getparameters();
        params.setflashmode(camera.parameters.flash_mode_torch);
        camera.setparameters(params);
        camera.startpreview();
        islighon = true;
 
        togglebgimage();
      }
 
    }
 
    // turning off flash
    private void turnoffflash() {
 
      if (islighon) {
        if (camera == null || params == null) {
          return;
        }
 
        params = camera.getparameters();
        params.setflashmode(camera.parameters.flash_mode_off);
        camera.setparameters(params);
        camera.stoppreview();
        islighon = false;
 
        togglebgimage();
      }
    }
 
    private void togglebgimage() {
      if (islighon) {
        bg.setimageresource(r.mipmap.f_on);
      } else {
        bg.setimageresource(r.mipmap.f_off);
      }
    }
 
    @override
    public void surfacechanged(surfaceholder holder, int format, int width, int height) {
 
    }
 
    @override
    public void surfacedestroyed(surfaceholder holder) {
      if (camera != null) {
        camera.stoppreview();
        camera.setpreviewcallback(null);
        camera.release();
        camera = null;
      }
    }
 
    @override
    public void surfacecreated(surfaceholder holder) {
      if (camera == null) {
        camera = camera.open();
        params = camera.getparameters();
        try {
          camera.setpreviewdisplay(holder);
        } catch (ioexception e) {
          camera.release();
          camera = null;
        }
      }
 
      turnonflash();
    }
 
  }
 
 
}

fragment_main_activity.xml

<relativelayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  >
 
  <surfaceview
    android:id="@+id/preview"
    android:layout_width="1dp"
    android:layout_height="1dp"/>
 
  <imageview
    android:id="@+id/flashlight_bg"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:src="@mipmap/f_on"
    android:scaletype="centercrop"
    />
 
  <imagebutton
    android:id="@+id/flashlight_button"
    android:layout_width="100dp"
    android:layout_height="200dp"
    android:layout_centerinparent="true"
    android:background="@android:color/transparent"
    android:text="fuck"/>
 
</relativelayout>

activity_main.xml

<framelayout xmlns:android="http://schemas.android.com/apk/res/android"
       android:id="@+id/container"
       android:layout_width="match_parent"
       android:layout_height="match_parent"
       />

androidmanifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="com.liujinghuiuncleapp.app.tool.flashlight" >
 
  <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.flash" />
 
  <application
    android:allowbackup="true"
    android:icon="@mipmap/ic_launcher"
    android:theme="@style/apptheme"
    android:label="@string/app_name" >
    <activity
      android:name=".mainactivity"
      android:label="@string/app_name" >
      <intent-filter>
        <action android:name="android.intent.action.main" />
 
        <category android:name="android.intent.category.launcher" />
      </intent-filter>
    </activity>
  </application>
 
</manifest>

以上所述就是本文的全部内容了，希望大家能够喜欢。