哎呀！！
我有一个列表视图，应该用数据库中的数据填充
代码：
private void onCreateDBAndDBTabled() {
myDB = this.openOrCreateDatabase(MY_DB_NAME, MODE_PRIVATE, null);
myDB.execSQL("CREATE TABLE IF NOT EXISTS " + MY_DB_TABLE
+ " (_id integer primary key autoincrement, name varchar(100), rate integer(1), eattime datetime)"
+";");
ArrayList<Pizza> list = new ArrayList<Pizza>();
Cursor cursor = this.myDB.query(MY_DB_TABLE, new String[] { "name" },null,null,null,null,null,null);
if (cursor.moveToFirst()) {
do {
Log.e("XXX", "Courser Enter: " + cursor.getString(0));
Pizza pizza = new Pizza();
pizza.title= cursor.getString(0);
list.add(pizza);
}
while (cursor.moveToNext());
}
if (cursor != null && !cursor.isClosed()) {
cursor.close();
}
Log.e("XXX", "Count:" + list.size());
Log.e("XXX", "Item[0] -->" + list.toArray()[0].toString());
CustomAdapter aa = new CustomAdapter(this, R.layout.customlistitem,list);
Log.e("XXX", String.valueOf(aa.getCount()));
lv.setAdapter(aa);
}
自定义适配器：
public class CustomAdapter extends ArrayAdapter<Pizza>{
private ArrayList<Pizza> pizzen;
public CustomAdapter(Context context, int textViewResourceId,ArrayList<Pizza> objects) {
super(context, textViewResourceId, objects);
this.pizzen = objects;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View v = convertView;
Pizza pizza = pizzen.get(position);
if (v == null) {
}
return v;//super.getView(position, convertView, parent);
}
披萨：
public class Pizza{
public String title;
public int rate;
public Date date;
}
错误：
09-30 08:58:38.661: ERROR/XXX(667): Courser Enter: EditText
09-30 08:58:38.671: ERROR/XXX(667): Count:1
09-30 08:58:38.671: ERROR/XXX(667): Item[0] -->com.korn.pizzacounter.Pizza@43b91850
09-30 08:58:38.671: ERROR/XXX(667): 1
09-30 08:58:38.751: ERROR/AndroidRuntime(667): Uncaught handler: thread main exiting due to uncaught exception
09-30 08:58:38.762: ERROR/AndroidRuntime(667): java.lang.NullPointerException
09-30 08:58:38.762: ERROR/AndroidRuntime(667): at android.widget.AbsListView.obtainView(AbsListView.java:1276)
09-30 08:58:38.762: ERROR/AndroidRuntime(667): at android.widget.ListView.makeAndAddView(ListView.java:1668)
09-30 08:58:38.762: ERROR/AndroidRuntime(667): at android.widget.ListView.fillDown(ListView.java:637)
09-30 08:58:38.762: ERROR/AndroidRuntime(667): at android.widget.ListView.fillFromTop(ListView.java:694)
09-30 08:58:38.762: ERROR/AndroidRuntime(667): at android.widget.ListView.layoutChildren(ListView.java:1521)
09-30 08:58:38.762: ERROR/AndroidRuntime(667): at android.widget.AbsListView.onLayout(AbsListView.java:1113)
09-30 08:58:38.762: ERROR/AndroidRuntime(667): at android.view.View.layout(View.java:6830)
虽然listsize为1，但错误为nullpoinerException（请参阅日志）
最佳答案
这是因为在您的getView()方法中，您没有对convertView进行充气，而是返回您的null。
你的getView应该是这样的inflatingarow.xml包含一个TextView.
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
TextView mTextView = null;
if (convertView == null) {
convertView = inflater.inflate(R.layout.row, parent, false);
mTextView = (TextView) convertView.findViewById(R.id.txt_list);
convertView.setTag(mTextView);
}
else{
mTextView = (TextView) convertView.getTag();
}
mTextView.setText(arrList.get(position));
return convertView;
}