Android 使用onResume()刷新活动
我有一个手电筒活动。正常情况下,它工作正常,但当我去任何其他活动,它停止工作 因此,当我回到手电筒活动时,我想刷新代码 我认为使用Android 使用onResume()刷新活动,android,Android,我有一个手电筒活动。正常情况下,它工作正常,但当我去任何其他活动,它停止工作 因此,当我回到手电筒活动时,我想刷新代码 我认为使用onResume()刷新对我帮助最大,但如何做到呢 public class FlashLightActivity extends Activity { //flag to detect flash is on or off private boolean isLighOn = false; private Camera camera; private Butt
onResume()
刷新对我帮助最大,但如何做到呢
public class FlashLightActivity extends Activity {
//flag to detect flash is on or off
private boolean isLighOn = false;
private Camera camera;
private Button next1, next2;
@Override
protected void onStop() {
super.onStop();
if (camera != null) {
camera.release();
}
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
next1 = (Button) findViewById(R.id.ebtn28_answer);
next1.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Intent myIntent = new Intent(view.getContext(), FullScreen.class);
startActivityForResult(myIntent, 0);
}
});
next2 = (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();
next2.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
if (isLighOn) {
Log.i("info", "torch is turn off!");
p.setFlashMode(Parameters.FLASH_MODE_OFF);
camera.setParameters(p);
camera.stopPreview();
isLighOn = false;
} else {
Log.i("info", "torch is turn on!");
p.setFlashMode(Parameters.FLASH_MODE_TORCH);
camera.setParameters(p);
camera.startPreview();
isLighOn = true;
}
}
});
}
}
您需要覆盖onPause和onResume。在onPause中,您需要释放相机。在onResume中,您需要重新请求它。当你不在活动中时,如果你试图握住相机,相机会不高兴
public void onPause(){
super.onPause();
if(camera != null){
camera.release();
camera = null;
}
}
public void onResume(){
super.onResume();
//Need to release if we already have one, or we won't get the camera
if(camera != null){
camera.release();
camera = null;
}
try {
camera = Camera.open();
}
catch (Exception e){
}
}
你是对的。但是非常新手,你能在这里给出你的建议代码吗?