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在ListView（使用自定義CursorAdapter）中，我試圖僅根據兩個ListView項目之間的日期是否更改來顯示分隔符，如下所示：as so http://i61.tinypic.com/vmqjkj.png。ListView中滾動時的日期分隔符
不幸的是，當我向下滾動，暫停一秒鐘，然後再次開始滾動時，我已經將分隔符設置在錯誤的位置（例如在這裏，請參閱消失ListView中第二項中的分隔符）： see the disappearance of the second item http://i61.tinypic.com/14lk7j7.jpg
或者，它可能出現在第三項中。
我所遇到的兩個主要問題：
- 在取決於滾動暫停的不同時間的日期分隔符的出現和消失，和
- 外觀日期分隔符是一個向上滾動的錯誤點。
我原則上了解到，出現這些問題，是因爲在lastDate我的適配器的行爲確實只考慮單向向下滾動，並且除了由ListView控件如何回收的意見和容器造成的。
我的問題，主要有：我怎麼能返工MyAdapter.java我的自定義的CursorAdapter或者我如何保存我的數據在MainFragment.java這樣我就可以顯示分體適當不管滾動的方向，或短暫停頓，然後rescrolls？
非常感謝你提前！
以下是MainFragment的代碼，適配器代碼以及ListView項目佈局的XML。
MyAdapter.java
package com.cpsashta.seplistview;
import android.content.Context;
import android.database.Cursor;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CursorAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import com.cpsashta.seplistview.DbContract.DbEntry;
public class MyAdapter extends CursorAdapter {
private LayoutInflater cursorInflater;
private Context mContext;
private Cursor mCursor;
private String lastDate;
TextView tvSep;
TextView tvName;
TextView tvTitle;
TextView tvDate;
TextView tvExp;
public MyAdapter(Context context, Cursor c, int flags) {
super(context,c,flags);
this.mContext = context;
this.mCursor = c;
cursorInflater = LayoutInflater.from(context);
}
@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
return cursorInflater.inflate(R.layout.list_layout_1, parent, false);
}
@Override
public void bindView(View view, Context context, Cursor c) {
tvTitle = (TextView) view.findViewById(R.id.tv_title);
tvName = (TextView) view.findViewById(R.id.tv_name);
tvSep = (TextView) view.findViewById(R.id.separator);
tvDate = (TextView) view.findViewById(R.id.tv_date);
tvExp = (TextView) view.findViewById(R.id.is_expanded_view);
String title = c.getString(c.getColumnIndex(DbEntry.COLNAME_TITLE));
String name = c.getString(c.getColumnIndex(DbEntry.COLNAME_NAME));
String date = c.getString(c.getColumnIndex(DbEntry.COLNAME_DATE));
tvTitle.setText(title);
tvName.setText(name);
tvDate.setText(date);
if (!date.equals(lastDate) || c.getPosition() == 0) {
tvSep.setVisibility(View.VISIBLE);
tvSep.setText(date);
tvExp.setText("true");
lastDate = date;
} else {
tvSep.setVisibility(View.GONE);
tvExp.setText("false");
}
}
}
list_layout_1.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/separator"
style="?android:attr/listSeparatorTextViewStyle"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textColor="@android:color/white"
android:background="#FF0000"
android:visibility="gone"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:visibility="gone"
android:id="@+id/is_expanded_view"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
android:text="Medium Text"
android:id="@+id/tv_title"
android:layout_gravity="center_horizontal" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/tv_date"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceSmall"
android:text="Small Text"
android:id="@+id/tv_name"
android:layout_gravity="right" />
</LinearLayout>
MainFragment.java
package com.cpsashta.seplistview;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.ListView;
import com.cpsashta.seplistview.DbContract.*;
public class MainFragment extends Fragment {
String[] names = {"Dick", "Sammy", "Manuel", "Jenny", "Kirk", "Shimmy"};
public static String titleSmile = "Damned crazy folks, Smile, you're on camera!";
String[] titles = {"Here we go again!", titleSmile};
String dateMonth = "Aug";
DbHelper mDbHelper;
SQLiteDatabase db;
Button button;
public MainFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
button = (Button) rootView.findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
LinearLayout ll = (LinearLayout) v.getParent();
addOneItem(ll);
}
});
return rootView;
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
ListView lv = (ListView) view.findViewById(R.id.listview);
Cursor c = getAll();
MyAdapter adapter = new MyAdapter(getActivity(),c,0);
lv.setAdapter(adapter);
}
//Occurs on button press, the view pressed is intended to be the rootView (a.k.a. the LinearLayout housing the ListView and button)
public void addOneItem(View view) {
newItemToDb();
ListView lv = (ListView) view.findViewById(R.id.listview);
MyAdapter adapter = (MyAdapter) lv.getAdapter();
adapter.notifyDataSetChanged();
}
//Adds random name, title, and date to the database
public void newItemToDb() {
if (db == null || !db.isOpen()) {
if (mDbHelper == null) {
mDbHelper = new DbHelper(getActivity());
}
db = mDbHelper.getWritableDatabase();
}
ContentValues values = new ContentValues();
int nameVal = (int)(Math.random() * names.length);
values.put(DbEntry.COLNAME_NAME, names[nameVal]);
int titleVal = (int) (Math.random() * titles.length);
values.put(DbEntry.COLNAME_TITLE, titles[titleVal]);
//Chooses a date from August 1 to August 10
//int dateDay = (int)(Math.random() * 10 + 1);
//FOR NOW choosing the date of Aug 1 or 2 only
int dateDay = (int)(Math.random() * 2 + 1);
String date = dateMonth + " " + dateDay;
values.put(DbEntry.COLNAME_DATE, date);
db.insert(DbEntry.TABLE_NAME, null, values);
db.close();
}
public Cursor getAll() {
if (db == null || !db.isOpen()) {
if (mDbHelper == null) {
mDbHelper = new DbHelper(getActivity());
}
db = mDbHelper.getWritableDatabase();
}
String[] projection = { DbEntry._ID,
DbEntry.COLNAME_TITLE,
DbEntry.COLNAME_NAME,
DbEntry.COLNAME_DATE
};
String sortOrder = null;
//TODO delete the sortOrder below
//String sortOrder = RecordingEntry.COLNAME_TAG_FULL
// + " DESC";
String[] selectionArgs = null;
String selection = null; // Setting this to null
Cursor c = db.query(DbEntry.TABLE_NAME,
projection,
selection,
selectionArgs,
null, // don't group the rows
null, // don't filter by row groups
sortOrder
);
return c;
}
}
編輯：我已經投入使用的基礎上，@ NT的建議解決方案，取代MainFragment與下面的bindView部分的結尾：
String lastDate = "";
int position = c.getPosition();
if (position != 0) {
c.moveToPosition(position - 1);
lastDate = c.getString(c.getColumnIndex(DbEntry.COLNAME_DATE));
c.moveToPosition(position);
}
if (position == 0 || !date.equals(lastDate)) {
separator.setVisibility(View.VISIBLE);
separator.setText(date);
} else {
separator.setVisibility(View.GONE);
}
正是我在找什麼。 Thanx夥伴。 – Androidster