Hi I followed I followed a tutorial here and wrote out the code, I tested it but the flashlight does not turn on and I cant figure out what's gone wrong. I left out the parts where there was sound because I preferred there not to be any.
package net.netne.benpaterson35;
import android.app.*;
import android.os.*;
import android.hardware.*;
import android.app.Activity;
import android.content.DialogInterface;
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.widget.Button;
public class MainActivity extends Activity
{
Button mainButton1;
private Camera camera;
private boolean isFlashOn;
private boolean hasFlash;
Parameters params;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mainButton1 = (Button) findViewById(R.id.mainButton1);
hasFlash = getApplicationContext().getPackageManager().
hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);
if (!hasFlash) {
AlertDialog alert = new AlertDialog.Builder(MainActivity.this)
.create();
alert.setTitle("Sorry");
alert.setMessage("This device doesn't have flash a flash light");
alert.setButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which){
finish();
}
});
alert.show();
return;
}
getCamera();
mainButton1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v){
if (isFlashOn){
turnOffFlash();}
else {
turnOnFlash();
}
};
});
}
private void getCamera(){
if (camera == null){
try {
camera = Camera.open();
params = camera.getParameters();
} catch (RuntimeException e) {
Log.e("Failed to open camera", e.getMessage());
}
}
}
private void turnOnFlash() {
if (!isFlashOn){
if (camera == null || params == null){
return;
}
params = camera.getParameters();
params.setFlashMode(Parameters.FLASH_MODE_TORCH);
camera.setParameters(params);
camera.startPreview();
isFlashOn = true;
}
}
private void turnOffFlash() {
if (isFlashOn){
if (camera == null || params == null) {
return;
}
params = camera.getParameters();
params.setFlashMode(Parameters.FLASH_MODE_OFF);
camera.setParameters(params);
camera.stopPreview();
isFlashOn = false;
}
}
@Override
protected void onDestroy()
{
super.onDestroy();
}
@Override
protected void onPause()
{
super.onPause();
turnOffFlash();
}
@Override
protected void onRestart()
{
super.onRestart();
}
@Override
protected void onResume()
{
super.onResume();
if(hasFlash)
turnOnFlash();
}
@Override
protected void onStart()
{
super.onStart();
getCamera();
}
@Override
protected void onStop()
{
super.onStop();
if (camera != null) {
camera.release();
camera = null;
}
}
}
Thanks for reading :)
if you are working on new device the code you followed wont work on newer devices i made it work on Lollipop device by following this code give it a try
mCam = Camera.open();
Camera.Parameters p = mCam.getParameters();
p.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
mCam.setParameters(p);
mPreviewTexture = new SurfaceTexture(0);
try {
mCam.setPreviewTexture(mPreviewTexture);
} catch (IOException ex) {
// Ignore
}
mCam.startPreview();
Did you add
<uses-permission android:name="android.permission.CAMERA" />
to your AndroidManifest?
Highly suspect you didn't add the permission.
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.