oh dear, i suggest learning java first.
D. On Thursday, 24 May 2012, HK Tsang <[email protected]> wrote: > I've passed the code when I add player = new MyPlayer() in onCreate. but next step, I change it to array: > > MyPlayer[] players; > > . > . > . > . > onCreate.... > players = new MyPlayer[4]; > > > then it also NPE. why it pass when I use single player but use array do not pass? > > == full code in main activity==== > package hktsang56.android.mjhelper; > import android.app.Activity; > import android.os.Bundle; > import android.view.View; > import android.widget.Button; > import android.widget.EditText; > import android.widget.TextView; > public class name_input extends Activity { > final static int NUM_PLAYER = 4; > private MyPlayer[] players; > MyPlayer player; > MarkSetting markSetting; > private EditText[] namesET; > Button bt[]; > private TextView tv; > int[] names = new int[]{ > R.id.et_p1, > R.id.et_p2, > R.id.et_p3, > R.id.et_p4 > }; > int[] btIds = new int[]{ > R.id.but_sendName, > R.id.but_clearName > }; > > @Override > protected void onCreate(Bundle savedInstanceState) { > // TODO Auto-generated method stub > super.onCreate(savedInstanceState); > setContentView(R.layout.player_input); > players = new MyPlayer[NUM_PLAYER]; > namesET = new EditText[NUM_PLAYER]; > bt = new Button[btIds.length]; > player = new MyPlayer(); > tv = (TextView) findViewById(R.id.tv_monitor); > tv.setText("onCreate"); > initButIds(); > } > private void initButIds(){ > for (int i=0; i<btIds.length; i++){ > bt[i] = (Button) findViewById(btIds[i]); > bt[i].setOnClickListener(myClickListener); > tv.setText("initButIds"); > > } > } > private View.OnClickListener myClickListener = new View.OnClickListener() { > > @Override > public void onClick(View v) { > // TODO Auto-generated method stub > tv.setText("onClick"); > but_click(v.getId()); > } > }; > public void but_click(int btId){ > switch (btId){ > case R.id.but_sendName: > tv.setText("but_click"); > setName(); > break; > case R.id.but_clearName: > clearName(); > break; > } > } > private void setName() { > // TODO Auto-generated method stub > String name="Null"; > for (int i=0; i<NUM_PLAYER; i++){ > namesET[i] = (EditText) findViewById(names[i]); > } > for (int i=0; i<NUM_PLAYER; i++){ > name = namesET[i].getText().toString().trim(); > players[i].setPlayerName(name); // remark: player.setPlayerName(name); <------------ can be run. > } > tv.setText(players[2].getPlayerName()); > > } > private void clearName() { > // TODO Auto-generated method stub > for (int i=0; i<NUM_PLAYER; i++){ > namesET[i].setText(""); > } > > } > } > > > On Wed, May 23, 2012 at 6:29 PM, Daniel Drozdzewski < [email protected]> wrote: >> >> Jason >> >> name == null >> >> would not cause NPE, as it is simple assignment to a member variable >> in MyPlayer class. If there was anything else within setName() that >> caused NPE, we could see it on the top of the stacktrace. >> >> The cause is that *player* reference in *player_input.setName()* is null. >> >> The way player object is being constructed is wrong: (player = new >> Player;) This code should not compile, so it begs the question, how >> did the OP manage to run it. >> >> There are many other issues with this code from the first look, like >> naming conventions, and auto generated comments dotting it, just to >> name the few. >> >> >> >> Daniel >> >> >> >> >> On 23 May 2012 10:56, Jason Teagle <[email protected]> wrote: >> >> I've create an object class but it cannot work. any mistake of my code? >> > >> > >> >> private void setName() { >> >> // TODO Auto-generated method stub >> >> getNameText(); >> >> for (int i=0; i<NUM_PLAYER; i++){ >> >> player.setPlayerName(name); // name is a String get from EditText by some >> >> code before >> >> } >> >> } >> > >> > >> >> when I run the programme, it have the following error code: >> > >> > >> >> 05-23 09:24:35.115: E/AndroidRuntime(438): java.lang.NullPointerException >> >> 05-23 09:24:35.115: E/AndroidRuntime(438): at hktsang56.android.mjhelper >> >> .name_input.setName(name_input.java:81) >> > >> > >> > Which of the lines in your source code is line 81? Is it the line that says >> > getNameText()? We need to see that method's definition, if that is the case, >> > since I can't see any other problem (if 'name' were coming out null, then >> > the error would be in setPlayerName() rather than in setName() - in fact it >> > probably wouldn't generate an error in such a case). >> > >> > Show us the code for getNameText(). You are possibly trying to access a >> > control that you have not filled out correctly. >> > >> > >> > >> > >> > >> > -- >> > You received this message because you are subscribed to the Google >> > Groups "Android Developers" group. >> > To post to this group, send email to [email protected] >> > To unsubscribe from this group, send email to >> > [email protected] >> > For more options, visit this group at >> > http://groups.google.com/group/android-developers?hl=en >> >> >> >> -- >> Daniel Drozdzewski >> >> -- >> You received this message because you are subscribed to the Google >> Groups "Android Developers" group. >> To post to this group, send email to [email protected] >> To unsubscribe from this group, send email to >> [email protected] >> For more options, visit this group at >> http://groups.google.com/group/android-developers?hl=en > > > -- > HK Tsang > > -- > You received this message because you are subscribed to the Google > Groups "Android Developers" group. > To post to this group, send email to [email protected] > To unsubscribe from this group, send email to > [email protected] > For more options, visit this group at > http://groups.google.com/group/android-developers?hl=en -- Daniel Drozdzewski -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
