在我的应用程序中，我有一个ListView。使用SimpleCursorAdapter在ListView中填充数据。我希望每当数据库发生变化或单击按钮时自动刷新ListView。我已经尝试过adapter.notifyDataSetChanged（）但它没有效率。我无法找到一个好的解决方案。我希望只要用户在EditText中输入值，然后按下发送按钮并将输入的数据保存在SQLite数据库中，就会刷新ListView。这是我的代码：
public class chatCursor extends Activity {
static MyListAdapter adapter;
ArrayList<String> item_id;
ArrayList<String> item_phone_num;
ArrayList<String> item_msg_body;
ArrayList<String> item_time;
ArrayList<String> item_flag;
ArrayList<String> items;
private Button btn_send;
DbManager manager;
Cursor Cursor;
//ViewHolder holder12;
String contact_for_chat;
String contact_no;
String message_body = "";
Calendar c;
SimpleDateFormat sdf;
String time;
EditText et_chat;
String flag;
String msg = "";
ListView lv_chat;
String[] from = new String[]{"Message_body","Time"};
int[] toIDs = new int[]{R.id.msg_body,R.id.time};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_chat);
Bundle bundle = getIntent().getExtras();
contact_for_chat = bundle.getString("contact_name");
contact_for_chat = contact_for_chat.replace(" ", "");
contact_no = Util.getContactNumber(contact_for_chat, chatCursor.this);
Toast.makeText(getApplicationContext(), contact_no, Toast.LENGTH_LONG).show();
manager = new DbManager(this);
Cursor = manager.Return_SMS(contact_for_chat);
c = Calendar.getInstance();
sdf = new SimpleDateFormat("dd:MMMM:yyyy HH:mm:ss a");
time = sdf.format(c.getTime());
item_id = new ArrayList<String>(Cursor.getCount());
item_phone_num = new ArrayList<String>(Cursor.getCount());
item_msg_body = new ArrayList<String>(Cursor.getCount());
item_time = new ArrayList<String>(Cursor.getCount());
item_flag = new ArrayList<String>(Cursor.getCount());
findViews();
showList();
//setActionBar();
btn_send.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
SendSMS();
showList();
}
});
lv_chat.setOnItemClickListener(new OnItemClickListener(){
@Override
public void onItemClick(AdapterView<?> arg0, View view, int position,
long arg3) {
Toast.makeText(getApplicationContext(), ""+position, Toast.LENGTH_LONG).show();
int itemId = Integer.valueOf(String.valueOf(position));
}});
}
private void showList() {
showEvents(Cursor);
adapter = new MyListAdapter(this,R.layout.activity_chat,
Cursor,
from,
toIDs);
lv_chat.setAdapter(adapter);
adapter.notifyDataSetChanged();
}
private void findViews() {
et_chat = (EditText)findViewById(R.id.et_chat);
btn_send = (Button)findViewById(R.id.button1);
lv_chat = (ListView)findViewById(R.id.list);
lv_chat.setDivider(this.getResources().getDrawable(android.R.color.transparent));
}
protected void SendSMS() {
SmsManager sms_manager = SmsManager.getDefault();
message_body = et_chat.getText().toString();
ArrayList<String> parts = sms_manager.divideMessage(message_body);
sms_manager.sendMultipartTextMessage(contact_no, null, parts, null, null);
flag = "1";
manager.Insert_sms_data(time, contact_for_chat, message_body,flag);
if(message_body.length()>0)
{
et_chat.setText("");
}
showList();
Toast.makeText(getApplicationContext(), "Message Sent", Toast.LENGTH_LONG).show();
private void showEvents(Cursor cursor) {
int i=0;
while (cursor.moveToNext()) {
item_id.add(i+"");
item_time.add(cursor.getString(1));
item_msg_body.add(cursor.getString(3));
item_phone_num.add(cursor.getString(2));
item_flag.add(cursor.getString(4));
i++;
}
}
public class MyListAdapter extends SimpleCursorAdapter {
Cursor myCursor;
Context myContext;
public MyListAdapter(Context context, int layout,
Cursor c, String[] from, int[] to) {
super(context, layout, c, from, to);
myCursor = c;
myContext = context;
}
public int getCount() {
return item_msg_body.size();
}
public Object getItem(int position) {
return item_msg_body.get(position);
}
public long getItemId(int position) {
return item_msg_body.get(position).hashCode();
}
public View getView(final int position, View arg1, ViewGroup arg2) {
View v = arg1;
ViewHolder holder = null;
if (v == null) {
LayoutInflater layoutinf = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = layoutinf.inflate(R.layout.row_chat, null);
holder = new ViewHolder();
// holder.tv_contact = (TextView) v.findViewById(R.id.phone_num);
holder.tv_sms_body = (TextView) v.findViewById(R.id.msg_body);
holder.tv_time = (TextView) v.findViewById(R.id.time);
v.setTag(holder);
} else {
holder = (ViewHolder) v.getTag();
}
if(item_flag.get(position).equals("1"))
{
RelativeLayout.LayoutParams params = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
params.addRule(RelativeLayout.ALIGN_PARENT_RIGHT,RelativeLayout.TRUE);
RelativeLayout.LayoutParams dateparams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
dateparams.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
dateparams.addRule(RelativeLayout.BELOW, R.id.msg_body);
holder.tv_sms_body.setBackgroundResource(R.drawable.bubble_green);
holder.tv_sms_body.setLayoutParams(params);
holder.tv_time.setLayoutParams(dateparams);
}
else if(item_flag.get(position).equals("0"))
{
holder.tv_sms_body.setBackgroundResource(R.drawable.bubble_yellow);
}
//holder.tv_contact.setText("" + item_phone_num.get(position));
holder.tv_sms_body.setText(item_msg_body.get(position));
holder.tv_time.setText(item_time.get(position));
return v;
}
}
public class ViewHolder {
private TextView tv_contact;
private TextView tv_sms_body;
private TextView tv_time;
}
}
任何帮助都将不胜感激。谢谢提前
答案 0 :(得分：0)
调用adapter.notifydatasetchanged（）方法刷新listview