[英]Android flashlight on nexus 5
我正在嘗試開發一個應用程序,用於在單擊切換時打開手電筒。 我嘗試了在網絡中找到的所有方法,但在nexus 5中均未成功。唯一有效的應用程序是cyanogenmod火炬,但是即使我采用了該代碼並將其寫入我的應用程序中,它也會創建一個通知,如果單擊該通知,它將打開cyanogenmod火炬應用程序而不是我的! 這是個問題!! 有沒有可能適用於nexus 5的簡單代碼?
public void turnOffFlashLight() {
try {
if (getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH)) {
cam.stopPreview();
cam.release();
cam = null;
}
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(getBaseContext(), "Exception throws in turning off flashlight.", Toast.LENGTH_SHORT).show();
}
}
public void turnOnFlashLight() {
try {
if (getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH)) {
cam = Camera.open();
cam.setPreviewTexture(new SurfaceTexture(0));
Parameters p = cam.getParameters();
p.setFlashMode(Parameters.FLASH_MODE_TORCH);
cam.setParameters(p);
cam.startPreview();
}
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(getBaseContext(), "Exception throws in turning on flashlight.", Toast.LENGTH_SHORT).show();
}
}
編輯:logcat
04-09 21:52:21.967: E/AndroidRuntime(5346): FATAL EXCEPTION: main
04-09 21:52:21.967: E/AndroidRuntime(5346): Process: com.lob.twixlight, PID: 5346
04-09 21:52:21.967: E/AndroidRuntime(5346): android.util.SuperNotCalledException: Activity {com.lob.twixlight/com.lob.twixlight.MainActivityTwixLight} did not call through to super.onStart()
04-09 21:52:21.967: E/AndroidRuntime(5346): at android.app.Activity.performStart(Activity.java:5243)
04-09 21:52:21.967: E/AndroidRuntime(5346): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2178)
04-09 21:52:21.967: E/AndroidRuntime(5346): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2265)
04-09 21:52:21.967: E/AndroidRuntime(5346): at android.app.ActivityThread.access$800(ActivityThread.java:145)
04-09 21:52:21.967: E/AndroidRuntime(5346): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1206)
04-09 21:52:21.967: E/AndroidRuntime(5346): at android.os.Handler.dispatchMessage(Handler.java:102)
04-09 21:52:21.967: E/AndroidRuntime(5346): at android.os.Looper.loop(Looper.java:136)
04-09 21:52:21.967: E/AndroidRuntime(5346): at android.app.ActivityThread.main(ActivityThread.java:5081)
04-09 21:52:21.967: E/AndroidRuntime(5346): at java.lang.reflect.Method.invokeNative(Native Method)
04-09 21:52:21.967: E/AndroidRuntime(5346): at java.lang.reflect.Method.invoke(Method.java:515)
04-09 21:52:21.967: E/AndroidRuntime(5346): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
04-09 21:52:21.967: E/AndroidRuntime(5346): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:607)
04-09 21:52:21.967: E/AndroidRuntime(5346): at dalvik.system.NativeStart.main(Native Method)
整個MainActivity
public class MainActivity extends Activity implements Callback {
private ImageView imageView3;
private ImageButton mButtonOn;
private Camera cam;
private SurfaceHolder mHolder ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
new AlertDialog.Builder(this);
setContentView(R.layout.activity_main);
mButtonOn = (ImageButton) findViewById(R.id.my_button);
imageView3 = (ImageView) findViewById(R.id.imageView3);
SurfaceView preview = (SurfaceView)findViewById(R.id.PREVIEW);
mHolder = preview.getHolder();
mHolder.addCallback(this);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public void info(View v) {
Intent intent = new Intent(this, FullscreenActivity.class);
startActivity(intent);
overridePendingTransition(R.anim.in, R.anim.out);
}
protected void onStart() {
super.onStart ();
SurfaceView preview = (SurfaceView)findViewById(R.id.PREVIEW);
mHolder = preview.getHolder();
mHolder.addCallback(this);
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
// TODO Auto-generated method stub
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
mHolder = holder;
try {
Log.i("SurfaceHolder", "setting preview");
cam.setPreviewDisplay(mHolder);
} catch (IOException e){
e.printStackTrace();
}
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub
cam.stopPreview();
mHolder = null;
}
}
好的,首先,請確保已將表面視圖添加到xml布局中,並且位於按鈕上方:
<SurfaceView
android:id="@+id/PREVIEW"
android:layout_width="1dp"
android:layout_height="1dp"/>
//image button comes below
<ImageButton
android:id="@+id/my_button" />
現在,在您的Java類中,實現SurfaceHolder.Callback接口,例如:
public class MyFlashlight extends Activity implements Callback
這將自動生成三種回調方法:
surfaceChanged();
surfaceCreated();
surfaceDestroyed();
現在就保留它。 在你的onStart();中 方法,添加以下內容:
SurfaceView preview = (SurfaceView)findViewById(R.id.PREVIEW);
SurfaceHolder mHolder = preview.getHolder();
mHolder.addCallback(this);
不要將此添加到onCreate(); 因為它(onCreate();)僅被調用一次,如果要重新啟動活動,它將導致問題。
在你的turnOnFlash();中 方法,照常做:
//get parameters
//set parameters
//set flashmode
//start preview
在您的surfaceCreated();中 方法,添加以下內容:
mHolder = holder;
try {
Log.i("SurfaceHolder", "setting preview");
camera.setPreviewDisplay(mHolder);
} catch (IOException e){
e.printStackTrace();
}
在您的surfaceDestroyed();中 方法,停止預覽:
camera.stopPreview();
mHolder = null;
保留surfaceChanged(); 空
而已!!!! 試試看!!!
這是一個完整的工作示例:
import android.app.Activity;
import android.content.Context;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MyFlashLight extends Activity implements Callback{
//flag to detect flash is on or off
private boolean isLighOn = false;
private Camera camera;
private Button button;
@Override
protected void onStart() {
super.onStart();
SurfaceView preview = (SurfaceView)findViewById(R.id.PREVIEW);
SurfaceHolder mHolder = preview.getHolder();
mHolder.addCallback(this);
}
}
@Override
protected void onStop() {
super.onStop();
if (camera != null) {
camera.release();
}
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
button = (Button) findViewById(R.id.buttonFlashlight);
Context context = this;
PackageManager pm = context.getPackageManager();
// if device support camera?
if (!pm.hasSystemFeature(PackageManager.FEATURE_CAMERA)) {
Log.e("err", "Device has no camera!");
return;
}
camera = Camera.open();
final Parameters p = camera.getParameters();
button.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
if (isLighOn) {
turnOffFlash();
} else {
turnOnFlash();
}
}
});
private void turnOnFlash(){
Log.i("info", "torch is turn on!");
p.setFlashMode(Parameters.FLASH_MODE_TORCH);
camera.setParameters(p);
camera.startPreview();
isLighOn = true;
}
private void turnOffFlash(){
Log.i("info", "torch is turn off!");
p.setFlashMode(Parameters.FLASH_MODE_OFF);
camera.setParameters(p);
camera.stopPreview();
isLighOn = false;
@Override
public void surfaceChanged(SurfaceHolder holder,int format,int width,int height){
}
@Override
public void surfaceCreated(SurfaceHolder holder){
mHolder = holder;
try {
Log.i("SurfaceHolder", "setting preview");
camera.setPreviewDisplay(mHolder);
} catch (IOException e){
e.printStackTrace();
}
}
@Override
public void surfaceDestroyed(SurfaceHolder holder){
Log.i("SurfaceHolder", "stopping preview");
camera.stopPreview();
mHolder = null;
}
}
}
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