我正在尝试使用游标适配器使用数据库数据填充listview。
问题： 它抛出一个运行时错误，应用程序崩溃。我无法理解错误。
码 用于游标适配器
public bookmarkcursoradapter(Context context, Cursor c) {
super(context, c, false);
}
@Override
public void bindView(View view, Context context, Cursor cursor) {
final TextView title=(TextView) view.findViewById(R.id.booktitle);
TextView url=(TextView) view.findViewById(R.id.bookurl);
TextView time=(TextView) view.findViewById(R.id.time);
title.setText(cursor.getString(1));
url.setText(cursor.getString(2));
time.setText(cursor.getString(3));
}
@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
LayoutInflater inflater3=(LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
return inflater3.inflate(R.layout.rowbookmark,parent,false);
}
}
主要活动中游标适配器的使用代码
Cursor bookmarkcursor;
bookmarkcursoradapter adapter;
ListView bookmark,history;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_browser);
bookmarkcursor = database.getallbookmark();
if (bookmarkcursor!=null) {
adapter = new bookmarkcursoradapter(browser.this, bookmarkcursor);
bookmark.setAdapter(adapter);
}
else{
adapter = new bookmarkcursoradapter(browser.this,null);
bookmark.setAdapter(adapter);
}
//bookmark adding
bookmarkbutton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
database.addContact(new databasemodel(titile,url2));
bookmarkcursor=database.getallbookmark();
adapter.changeCursor(bookmarkcursor);
}
});
bookmark.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
bookmarkcursor.moveToPosition(position);
String bookurl= database.geturlbookmark(bookmarkcursor.getInt(0));
mTabHost.setCurrentTab(mTabHost.getCurrentTab());
wb.loadUrl(bookurl);
drawer.closeDrawer(Gravity.END,TRUE);
}
});
bookmark.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
bookmarkcursor.moveToPosition(position);
database.deletebookmark(bookmarkcursor.getInt(0));
bookmarkcursor=database.getallbookmark();
adapter.changeCursor(bookmarkcursor);
adapter.notifyDataSetChanged();
Toast.makeText(browser.this,"bookmarkdeleted", LENGTH_LONG).show();
return true;
}
});
**注意：**我只发布主要活动的cursoradapter相关代码
数据库代码
public class databasehelper extends SQLiteOpenHelper {
private static int DATABASE_VERSION =25;
public static final String DATABASE_NAME = "browse1.db";
public static final String TABLE_BOOKMARK = "Bookmark";
public static final String TABLE_HISTORY= "History";
public static final String COLUMN_ID = "ID";
public static final String COLUMN_title = "Title";
public static final String COLUMN_url = "Url";
public static final String COLUMN_creat = "createdat";
public databasehelper(Context context) {
super(context, DATABASE_NAME,null,DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("create table " + TABLE_BOOKMARK + " ( " + COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT," + COLUMN_title + " TEXT, " + COLUMN_url + " TEXT," + COLUMN_creat + " TEXT "+");");
db.execSQL("create table " + TABLE_HISTORY + " ( " + COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT," + COLUMN_title + " TEXT, " + COLUMN_url + " TEXT," + COLUMN_creat + " TEXT "+");");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_BOOKMARK);
db.execSQL("DROP TABLE IF EXISTS " + TABLE_HISTORY);
// Create tables again
onCreate(db);
}
public void addContact(databasemodel d) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(COLUMN_title, d.gettitle()); // Contact Name
values.put(COLUMN_url, d.getURL()); // Contact Phone
values.put(COLUMN_creat,d.getDateTime());
// Inserting Row
db.insert(TABLE_BOOKMARK, null, values);
db.close(); // Closing database connection
}
public void addHistory(databasemodel d) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(COLUMN_title, d.gettitle()); // Contact Name
values.put(COLUMN_url, d.getURL()); // Contact Phone
values.put(COLUMN_creat,d.getDateTime());
// Inserting Row
db.insert(TABLE_HISTORY, null, values);
db.close(); // Closing database connection
}
/*public ArrayList<databasemodel> getAllContacts() {
ArrayList<databasemodel> contactList = new ArrayList<databasemodel>();
// Select All Query
String selectQuery = "SELECT * FROM " + TABLE_BOOKMARK;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
databasemodel structure = new databasemodel();
structure.setid(Integer.parseInt(cursor.getString(0)));
structure.setTitle(cursor.getString(1));
structure.setURL(cursor.getString(2));
structure.setTIME(cursor.getString(3));
// Adding contact to list
contactList.add(structure);
} while (cursor.moveToNext());
}
// return contact list
return contactList;
}*/
public Cursor getallbookmark(){
SQLiteDatabase db = this.getWritableDatabase();
Cursor bookmarkcursordb;
String selectQuery = "SELECT * FROM " + TABLE_BOOKMARK;
bookmarkcursordb=db.rawQuery(selectQuery,null);
if (bookmarkcursordb != null) {
bookmarkcursordb.moveToFirst();
}
return bookmarkcursordb;
}
public ArrayList<databasemodel> getAllhistory() {
ArrayList<databasemodel> contactList = new ArrayList<databasemodel>();
// Select All Query
String selectQuery = "SELECT * FROM " + TABLE_HISTORY;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
databasemodel structure = new databasemodel();
structure.setid(Integer.parseInt(cursor.getString(0)));
structure.setTitle(cursor.getString(1));
structure.setURL(cursor.getString(2));
structure.setTIME(cursor.getString(3));
// Adding contact to list
contactList.add(structure);
} while (cursor.moveToNext());
}
// return contact list
return contactList;
}
public void deletebookmark(int id) {
SQLiteDatabase db = this.getWritableDatabase();
db.execSQL(" DELETE FROM " + TABLE_BOOKMARK + " WHERE " + COLUMN_ID+ " = " + " ' " + id + " ' ");
db.close();
}
public String geturlbookmark( int id){
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor;
String QUERY=" SELECT " + COLUMN_url + " FROM " + TABLE_BOOKMARK + " WHERE " + COLUMN_ID + " = " + " ' " + id + " ' ";
cursor=db.rawQuery(QUERY,null);
String url = cursor.getString(0);
cursor.close();
return url;
}
public ArrayList<String> getbookmarkurl()
{
ArrayList<String> bookmarkurl= new ArrayList<>();
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor;
String QUERY=" SELECT " + COLUMN_url + " FROM " + TABLE_BOOKMARK ;
cursor=db.rawQuery(QUERY,null);
if (cursor.moveToFirst()) {
do {
// Adding contact to list
bookmarkurl.add(cursor.getString(0));
} while (cursor.moveToNext());
}
// return contact list
return bookmarkurl;
}
}
logcat错误
05-02 21:11:53.111 3901-3901/com.example.lenovo1.tabhostbrowser E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.lenovo1.tabhostbrowser, PID: 3901
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.lenovo1.tabhostbrowser/com.example.lenovo1.tabhostbrowser.browser}: java.lang.IllegalArgumentException: column '_id' does not exist
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2665)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6119)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
Caused by: java.lang.IllegalArgumentException: column '_id' does not exist
at android.database.AbstractCursor.getColumnIndexOrThrow(AbstractCursor.java:333)
at android.widget.CursorAdapter.init(CursorAdapter.java:180)
at android.widget.CursorAdapter.<init>(CursorAdapter.java:144)
at com.example.lenovo1.tabhostbrowser.bookmarkcursoradapter.<init>(bookmarkcursoradapter.java:0)
at com.example.lenovo1.tabhostbrowser.browser.onCreate(browser.java:222)
at android.app.Activity.performCreate(Activity.java:6679)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118)
plz帮助。提前谢谢。