我試圖在單擊按鈕時在列表視圖中添加行,但是我的應用程序每次都會崩潰。 這裏是我的代碼:使用按鈕動態添加新行
public class MTCRichGraphicsActivity extends Activity {
int ELEMENT_COUNT = 3;
int position=0;
Button bAddView;
String[] elements = new String[ELEMENT_COUNT];
int r =0 ;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
bAddView = (Button) findViewById(R.id.bNewEvent);
final ListView list = (ListView) findViewById(R.id.list3d);
bAddView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch(v.getId())
{
case R.id.bNewEvent :
for (int i = 0; i< ELEMENT_COUNT; i++) {
elements[i] = String.valueOf(i);
}
final MyAdapter adapter = new MyAdapter(MTCRichGraphicsActivity.this,elements);
adapter.notifyDataSetChanged();
//list.setScrollY(currentPosition);
//list.setTranslationY(currentPosition);
list.setDivider(null);
list.setAdapter(adapter);
adapter.notifyDataSetChanged();
ELEMENT_COUNT = ELEMENT_COUNT + 3;
}
}
});
}
}
在這裏,我想每次加3行的按鈕(即bNewEvent)被點擊,所以我通過3每次遞增ELEMENT_COUNT。它第一次正常工作,但是當我第二次按下按鈕時,它會崩潰。
這裏是我的適配器類:
public class MyAdapter extends BaseAdapter {
private final LayoutInflater mInflater;
private final String[] mItems;
TextView t;
ViewHolder holder;
public MyAdapter(Activity c,String[] objects) {
mInflater = c.getLayoutInflater();
mItems = objects;
}
public int getCount() {
return mItems.length;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
TextView t;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.listitem2, parent,false);
}
holder = new ViewHolder();
holder.t1 = (TextView) convertView.findViewById(R.id.tv1);
holder.t2 = (TextView) convertView.findViewById(R.id.tv2);
holder.t3 = (TextView) convertView.findViewById(R.id.tv3);
holder.t4 = (TextView) convertView.findViewById(R.id.tv4);
holder.t1.setText("Title"+position);
position = position + 3;
//((ImageView)convertView).setTextAlignment(1);
return convertView;
}
@Override
public Object getItem(int position) {
return mItems[position];
}
@Override
public long getItemId(int position) {
return position;
}
}
您能不能告訴我們您的logcat的? – 2013-03-25 12:12:52
使用集合類而不是像列表 這樣的數組,您不能在運行時增加數組的大小,它的不可變 – 2013-03-25 12:17:38
@Premsuraj是對的。你必須使用arraylist而不是數組,因爲arraylist不需要初始化元素的數量。 – 2013-03-25 12:27:42