wie meinst du die importe nicht vergessen eclipse weisst einen doch dann darauf hin wenn man die vergisst, oder ?
der code sieht jetzt so aus und stürzt immer noch beim öffnen ab:
package com.example.eeasy;
import android.app.AlertDialog;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarActivity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.Button;
public class MainActivity extends ActionBarActivity {
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ActionBar actionBar = getSupportActionBar();
actionBar.hide();
Button button1 = (Button) findViewById(R.id.button1);
button1.setOnClickListener( new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
AlertDialog.Builder dlgAlert = new AlertDialog.Builder(MainActivity.this);
dlgAlert.setMessage("wrong password or username"
;
dlgAlert.setTitle("Error Message..."
;
dlgAlert.setCancelable(true);
dlgAlert.create().show();
}
});
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}
}
@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;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container,
false);
return rootView;
}
}
}
LOGCAT :
05-16 09:35:54.845: E/AndroidRuntime(334): FATAL EXCEPTION: main
05-16 09:35:54.845: E/AndroidRuntime(334): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.eeasy/com.example.eeasy.MainActivity}: java.lang.NullPointerException
05-16 09:35:54.845: E/AndroidRuntime(334): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
05-16 09:35:54.845: E/AndroidRuntime(334): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
05-16 09:35:54.845: E/AndroidRuntime(334): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
05-16 09:35:54.845: E/AndroidRuntime(334): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
05-16 09:35:54.845: E/AndroidRuntime(334): at android.os.Handler.dispatchMessage(Handler.java:99)
05-16 09:35:54.845: E/AndroidRuntime(334): at android.os.Looper.loop(Looper.java:123)
05-16 09:35:54.845: E/AndroidRuntime(334): at android.app.ActivityThread.main(ActivityThread.java:4627)
05-16 09:35:54.845: E/AndroidRuntime(334): at java.lang.reflect.Method.invokeNative(Native Method)
05-16 09:35:54.845: E/AndroidRuntime(334): at java.lang.reflect.Method.invoke(Method.java:521)
05-16 09:35:54.845: E/AndroidRuntime(334): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
05-16 09:35:54.845: E/AndroidRuntime(334): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
05-16 09:35:54.845: E/AndroidRuntime(334): at dalvik.system.NativeStart.main(Native Method)
05-16 09:35:54.845: E/AndroidRuntime(334): Caused by: java.lang.NullPointerException
05-16 09:35:54.845: E/AndroidRuntime(334): at com.example.eeasy.MainActivity.onCreate(MainActivity.java:27)
05-16 09:35:54.845: E/AndroidRuntime(334): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
05-16 09:35:54.845: E/AndroidRuntime(334): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
05-16 09:35:54.845: E/AndroidRuntime(334): ... 11 more
— geändert am 16.05.2014, 11:38:07