import android.view.window; 尝试在空对象引用上调用虚拟方法‘android.view.Window$回调...

尝试在空对象引用上调用虚拟方法‘android.view.Window$回调-android.view.Window.getCallback()’

当我SplashActivity打开LoginActivity我的应用程序崩溃了。

以下是我的SplashActivity.java:packagecom.example.android.appName;importandroid.content.Intent;importandroid.os.Bundle;importandroid.support.v7.app.AppCompatActivity;

importjava.util.Timer;importjava.util.TimerTask;publicclassSplashActivityextendsAppCompatActivity{

@Override

protectedvoidonCreate(BundlesavedInstanceState){

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_splash);

Timertimer=newTimer();

timer.schedule(newTimerTask(){

publicvoidrun(){

Intentintent=newIntent(SplashActivity.this,LoginActivity.class);

startActivity(intent);

finish();

}

},1500);

}}

我的LoginActivity.java:packagecom.example.android.appName;importandroid.content.Intent;importandroid.os.Bundle;importandroid.support.v7.app.AppCompatActivity;

importandroid.view.KeyEvent;importandroid.view.Menu;importandroid.view.MenuInflater;importandroid.view.MenuItem;importandroid.view.View;

importandroid.widget.EditText;importandroid.widget.ProgressBar;importandroid.widget.TextView;

publicclassLoginActivityextendsAppCompatActivity{

privateEditTextusernameField=(EditText)findViewById(R.id.username),

passwordField=(EditText)findViewById(R.id.password);

privateTextViewerror=(TextView)findViewById(R.id.error);

privateProgressBarprogress=(ProgressBar)findViewById(R.id.progress);

@Override

protectedvoidonCreate(BundlesavedInstanceState){

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_login);

}

@Override

publicbooleanonCreateOptionsMenu(Menumenu){

MenuInflaterinflater=getMenuInflater();

inflater.inflate(R.menu.login_menu,menu);

returntrue;

}