Android 回电话上课不起作用
我有一个应用程序，这是一个火炬。我已经添加了一个功能，如果用户没有闪存设备，那么它应该启动一个前屏幕火炬。这是我的密码 LightsOn.java 现在如果用户没有flash，那么这个类将被启动 FrontScreen.java 现在，当我从这个类中调用第一个类（在选项菜单项2中）时，它显示的是NullPointerException 这是我的日志信息Android 回电话上课不起作用,android,flashlight,Android,Flashlight,我有一个应用程序，这是一个火炬。我已经添加了一个功能，如果用户没有闪存设备，那么它应该启动一个前屏幕火炬。这是我的密码 LightsOn.java 现在如果用户没有flash，那么这个类将被启动 FrontScreen.java 现在，当我从这个类中调用第一个类（在选项菜单项2中）时，它显示的是NullPointerException 这是我的日志信息 谁能帮帮我吗。。Thanx提前到达。只是一个猜测。如果设置了hasFlash标志，onResume中的代码似乎会被执行。如果是这样，onResu
谁能帮帮我吗。。Thanx提前到达。只是一个猜测。如果设置了hasFlash标志，onResume中的代码似乎会被执行。如果是这样，onResume应该是这样的
@Override
protected void onResume() {
super.onResume();
if(hasFlash){
myparas = mycamera.getParameters();
myparas.setFlashMode(Parameters.FLASH_MODE_TORCH);
mycamera.setParameters(myparas);
mycamera.startPreview();
flashon=true;
}
}
显示您的日志数据请查看更新的问题。我的onResume和您的onResume之间有什么区别？区别在于如果您不使用任何大括号表示if，那么只执行第一条语句。对不起，我没有注意到。onResume中肯定存在问题。有人能猜出来吗。！你查过我答案的答案了吗？
public class FrontScreen extends Activity
{
Boolean torchon=false;
ImageView button;
RelativeLayout lyt;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.frontscreen);
lyt=(RelativeLayout)findViewById(R.id.layout);
button=(ImageView)findViewById(R.id.power);
button.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(torchon)
{
lyt.setBackgroundResource(R.drawable.background);
torchon=false;
}
else
{
lyt.setBackgroundResource(R.drawable.fronttorch);
torchon=true;
}
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu m)
{
MenuInflater inf=getMenuInflater();
inf.inflate(R.menu.frontmenu,m);
return true;
}
public boolean onOptionsItemSelected(MenuItem itm)
{
if(itm.getItemId()==R.id.it1)
{
if(torchon)
{
lyt.setBackgroundResource(R.drawable.background);
torchon=false;
}
else
{
lyt.setBackgroundResource(R.drawable.fronttorch);
torchon=true;
}
}
**else if(itm.getItemId()==R.id.it2)
{
Intent intents = new Intent(FrontScreen.this,LightsOn.class);
startActivity(intents);
}**
else if(itm.getItemId()==R.id.it3)
{
Toast.makeText(getApplicationContext(), "Website getting launched soon..!!", Toast.LENGTH_SHORT).show();
}
else if(itm.getItemId()==R.id.it4)
{
}
else if(itm.getItemId()==R.id.it5)
{
openDialog();
}
return true;
}
private void openDialog(){
final Dialog dialog = new Dialog(FrontScreen.this);
dialog.setTitle("Thank You..");
dialog.setContentView(R.layout.dialoglayout);
dialog.getWindow().getAttributes().windowAnimations = R.style.DialogAnimation;
Button btnDismiss = (Button)dialog.getWindow().findViewById(R.id.exit);
Button btnCancel = (Button)dialog.getWindow().findViewById(R.id.cancel);
btnDismiss.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v)
{
if(torchon)
{
lyt.setBackgroundResource(R.drawable.background);
}
else
{
finish();
moveTaskToBack(true);
}
}});
btnCancel.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
dialog.dismiss();
}});
dialog.show();
}
}
07-10 13:27:40.111: W/dalvikvm(17187): threadid=1: thread exiting with uncaught exception (group=0x4104e258)
07-10 13:27:40.115: E/AndroidRuntime(17187): FATAL EXCEPTION: main
07-10 13:27:40.115: E/AndroidRuntime(17187): java.lang.RuntimeException: Unable to resume activity {akshat.jaiswal.showmethatapp/akshat.jaiswal.showmethatapp.LightsOn}: java.lang.NullPointerException
07-10 13:27:40.115: E/AndroidRuntime(17187): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2595)
07-10 13:27:40.115: E/AndroidRuntime(17187): at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2623)
07-10 13:27:40.115: E/AndroidRuntime(17187): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2109)
07-10 13:27:40.115: E/AndroidRuntime(17187): at android.app.ActivityThread.access$600(ActivityThread.java:134)
07-10 13:27:40.115: E/AndroidRuntime(17187): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1247)
07-10 13:27:40.115: E/AndroidRuntime(17187): at android.os.Handler.dispatchMessage(Handler.java:99)
07-10 13:27:40.115: E/AndroidRuntime(17187): at android.os.Looper.loop(Looper.java:154)
07-10 13:27:40.115: E/AndroidRuntime(17187): at android.app.ActivityThread.main(ActivityThread.java:4624)
07-10 13:27:40.115: E/AndroidRuntime(17187): at java.lang.reflect.Method.invokeNative(Native Method)
07-10 13:27:40.115: E/AndroidRuntime(17187): at java.lang.reflect.Method.invoke(Method.java:511)
07-10 13:27:40.115: E/AndroidRuntime(17187): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:809)
07-10 13:27:40.115: E/AndroidRuntime(17187): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:576)
07-10 13:27:40.115: E/AndroidRuntime(17187): at dalvik.system.NativeStart.main(Native Method)
07-10 13:27:40.115: E/AndroidRuntime(17187): Caused by: java.lang.NullPointerException
07-10 13:27:40.115: E/AndroidRuntime(17187): at akshat.jaiswal.showmethatapp.LightsOn.onResume(LightsOn.java:169)
07-10 13:27:40.115: E/AndroidRuntime(17187): at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1159)
07-10 13:27:40.115: E/AndroidRuntime(17187): at android.app.Activity.performResume(Activity.java:4553)
07-10 13:27:40.115: E/AndroidRuntime(17187): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2581)
07-10 13:27:40.115: E/AndroidRuntime(17187): ... 12 more
@Override
protected void onResume() {
super.onResume();
if(hasFlash){
myparas = mycamera.getParameters();
myparas.setFlashMode(Parameters.FLASH_MODE_TORCH);
mycamera.setParameters(myparas);
mycamera.startPreview();
flashon=true;
}
}