我正在尝试创建 Android 应用程序，该应用程序需要用户输入来创建播放器列表并保持顺序，但我一直在尝试使用带有 int 位置和字符串名称的 ArrayList 来执行此操作，但是当我尝试playList.add(player)我的应用程序崩溃时。
我一直在尝试添加到playerList = new ArrayList<Player>();我尝试过的 ArrayListList<Player> = new ArrayList<Player>中，但没有成功。
数据被传回并显示在 Toast 但现在是 ListView 项目。我错过了什么？这是我的主要活动：
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnTouchListener;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TableRow;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity implements OnTouchListener {
private static final int REQUEST_CODE = 10;
private SharedPreferences savedPlayerPositions;
private PlayerActivity playerActivity;
public List<Player> playerList = new ArrayList<Player>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// set up preferences
savedPlayerPositions = getSharedPreferences("playerPositions",
MODE_PRIVATE);
ListView lv = (ListView) findViewById(R.id.list);
List<Player> playerList = new ArrayList<Player>();
CustomListViewAdapter adapter = new CustomListViewAdapter(this,
playerList);
lv.setAdapter(adapter);
Button addPlayerButton = (Button) findViewById(R.id.button1);
addPlayerButton.setOnClickListener(addPlayerButtonListener);
playerActivity = new PlayerActivity();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public OnClickListener addPlayerButtonListener = new OnClickListener() {
@Override
public void onClick(View v) {
// onClick go to player input screen and PlayerActivity
Intent intent = new Intent();
intent.setClass(MainActivity.this, PlayerActivity.class);
startActivityForResult(intent, REQUEST_CODE);
}
};
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 10) {
String position = data.getStringExtra("battingPosition");
String name = data.getStringExtra("playerName");
int positionInt = Integer.valueOf(position);
Player player = new Player(positionInt, name);
**playerList.add(player);**
Toast.makeText(getApplicationContext(), position + " " + name,
Toast.LENGTH_LONG).show();
}
这是我的 customListViewAdapter：
import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.TextView;
public class CustomListViewAdapter extends BaseAdapter
{
LayoutInflater inflater;
List<Player> playerList;
public CustomListViewAdapter(Activity context, List<Player> playerList) {
super();
this.playerList = playerList;
this.inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);}
@Override
public int getCount() {
// TODO Auto-generated method stub
return playerList.size(); }
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return null; }
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return 0; }
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
Player player = playerList.get(position);
View vi=convertView;
if(convertView==null)
vi = inflater.inflate(R.layout.new_player_view, null);
//assign components from new_player_view
TextView playerInfo = (TextView)vi.findViewById(R.id.txtV_player_input_name_title);
Button editButton = (Button) vi.findViewById(R.id.btn_Edit_Title);
editButton.setOnClickListener(MainActivity.editPlayerButtonListener);
playerInfo.setText(player.batPosition + " " + player.name);
return vi;
}
}
xml 主要活动：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/txtV_battingOrder_Title"
android:textSize="20sp" />
<Button
android:id="@+id/button1"
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/btn_AddButton_title" />
<ListView
android:id="@+id/list"
android:layout_width="fill_parent"
android:layout_height="442dp"
android:layout_weight="0.89" >
</ListView>
</LinearLayout>
添加到 listView 的行：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:background="@android:color/transparent"
android:padding="5dp" >
<TextView
android:id="@+id/txtV_player_input_name_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="25dp"
android:layout_marginTop="21dp"
android:maxLength="2"
android:maxLines="1"
android:width="180dp" />
<Button
android:id="@+id/btn_Edit_Title"
style="?android:attr/buttonStyleSmall"
android:layout_width="@dimen/btn_edit_player_width"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/txtV_player_input_position_title"
android:layout_alignBottom="@+id/txtV_player_input_position_title"
android:layout_alignParentRight="true"
android:layout_marginRight="14dp"
android:padding="3dp"
android:text="@string/bnt_Edit_title" />
</RelativeLayout>