我有一个ListView,其中的地点名称显示在SQLite数据库中。数据库有5列:_id
,Map_no
,Location
,Date
, Notes
。
当我点击ListView
中的某个项目时,我希望能够从数据库中获取Map_no
,Location
,Date
和Notes
并将它们作为附加内容存储在意图中,以便我能够将它们传递给下一个活动。我曾尝试编写自己的名为getLocation
的查询来返回该位置,并查找了有关该主题的不同教程并搜索 SO 以获取答案,但无济于事。
MainActivity.java
package com.********************.******.***************;
import android.app.Activity;
import android.database.Cursor;
import android.os.Bundle;
import android.support.v4.widget.SimpleCursorAdapter;
import android.view.Window;
import android.widget.AdapterView;
import android.widget.Button;
import android.content.Intent;
import android.view.View;
import android.widget.ListView;
public class MainActivity extends Activity {
private static final String TAG = "MainActivity";
DBHelper dbHelper;
SimpleCursorAdapter simpleCursorAdapter;
private String map;
private String location;
private String date;
private String note;
public MainActivity() {
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
requestWindowFeature(Window.FEATURE_ACTION_BAR);
setContentView(R.layout.activity_main);
dbHelper = new DBHelper(this);
displayList();
}
public void displayList() {
final Cursor cursor = dbHelper.getData();
String from[] = new String[]{dbHelper.LOCATION};
int to[] = new int[]{R.id.ListLayout1};
simpleCursorAdapter = new SimpleCursorAdapter(this, R.layout.row_item, cursor, from, to, 0);
final ListView listView = (ListView) findViewById(R.id.list);
listView.setAdapter(simpleCursorAdapter);
while (cursor.moveToNext());
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
String location = dbHelper.getLocation(l).toString();
Intent intent = new Intent(MainActivity.this, EditData.class);
intent.putExtra("Location", location);
intent.putExtra("Date", DBHelper.DATE);
intent.putExtra("Not_at_homes", DBHelper.NOTATHOMES);
startActivity(intent);
}
});
}
public void toInput(View view) {
Button addbutton = (Button) findViewById(R.id.addButton);
Intent intent = new Intent(MainActivity.this, InputPage.class);
startActivity(intent);
}
}
DBhelper.java
package com.******************.*****.****************;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class DBHelper extends SQLiteOpenHelper {
public static final String DATABASE_NAME = "App_database.db";
public static final String TABLE_NAME = "App_data_table";
public static final String MAP_NO = "Map_no";
public static final String LOCATION = "Location";
public static final String DATE = "Date";
public static final String NOTES = "Notes";
public static final String _id = "_id";
public static final String TAG = "DBHelper";
private static DBHelper instance = null;
public DBHelper(Context context) {
super(context, DATABASE_NAME, null, 1);
}
@Override
public void onCreate(SQLiteDatabase db) {
String createTable = "CREATE TABLE " + TABLE_NAME + "(_id INTEGER PRIMARY KEY AUTOINCREMENT, " + MAP_NO + " INTEGER, " + LOCATION + " TEXT, " + DATE + " INTEGER, " + Notes + " TEXT)";
db.execSQL(createTable);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
onCreate(db);
}
public boolean insertData(String Map_no, String Location, String Date, String Not_at_homes) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(MAP_NO, Map_no);
contentValues.put(LOCATION, Location);
contentValues.put(DATE, Date);
contentValues.put(NOTES, Notes);
Log.d(TAG, "addData: Adding " + Location + " to " + TABLE_NAME);
long result = db.insert(TABLE_NAME, null, contentValues);
if (result == -1) {
return false;
} else {
return true;
}
}
//getting data
public Cursor getData() {
SQLiteDatabase db = this.getReadableDatabase();
String query = "SELECT * FROM " + TABLE_NAME;
Cursor data = db.rawQuery(query, null);
return data;
}
public Cursor getItemID(String map, String location, String date, String notes) {
SQLiteDatabase db = this.getWritableDatabase();
String query = "SELECT _id FROM " + TABLE_NAME +
" WHERE " + MAP_NO + " = '" + map + "'" + " AND " + LOCATION + " = '" + location + "'" +
" AND " + DATE + " = '" + date + "'" + " AND "
+ NOTES + " = '" + Notes+ "'";
Cursor data = db.rawQuery(query, null);
return data;
}
public void updateData(int id,String newMapNo, String oldMapNo, String newLocation, String oldLocation, String newDate, String oldDate, String newNotes, String oldNotes){
SQLiteDatabase db = this.getWritableDatabase();
String query = "UPDATE " + TABLE_NAME + " SET " + MAP_NO +
" = '" + newMapNo + " WHERE " + _id + " = '" + id + "'" +
" AND " + MAP_NO + " = '" + oldMapNo + "'"+ LOCATION +
" = '" + newLocation + " WHERE " + _id + " = '" + id + "'" +
" AND " + LOCATION + " = '" + oldLocation + "'"+ DATE +
" = '" + newDate + " WHERE " + _id + " = '" + id + "'" +
" AND " + DATE + " = '" + oldDate + "'"+ NOTES+
" = '" + newNotes + " WHERE " + _id + " = '" + id + "'" +
" AND " + NOTES + " = '" + oldNotes + "'";
Log.d(TAG, "updating: query: " + query);
Log.d(TAG, "updating: Setting map number, Location, Date and Not at homes to new values: Map number: " +
newMapNo + " Location: " + newLocation + " Date: " +
newDate + " Notes: " + newNotes);
db.execSQL(query);
}
public void deleteData(int id, String mapNo, String location, String date, String Notes){
SQLiteDatabase database = this.getWritableDatabase();
String query = "DELETE FROM " + TABLE_NAME + " WHERE "
+ _id + " = '" + id + "'" + " AND " + MAP_NO + " = '" + mapNo + "'" +
LOCATION + " = '" + location + "'" + DATE + " = '" + date + "'" + NOTES +
" = '" + Notes + "'";
Log.d(TAG, "deleting: query: " + query);
Log.d(TAG, "deleting: Deleting note with values: Map number: " + mapNo + " Location: " + location + " Created on: " + date + " With notes: " + Notes + ".");
database.execSQL(query);
}
public static DBHelper getInstance(Context context){
if (instance == null){
instance = new DBHelper(context.getApplicationContext());
}
return instance;
}
public Cursor getLocation(long id){
SQLiteDatabase db = this.getWritableDatabase();
String query = "SELECT " + LOCATION + " FROM " + TABLE_NAME + " WHERE " + _id + " = '" + id + "'";
Cursor rowDataLocation = db.rawQuery(query, null);
return rowDataLocation;
}
}
答案 0 :(得分:1)
您可以尝试使用
// =======================================================
var idTrnf = charIDToTypeID( "Trnf" );
var desc2 = new ActionDescriptor();
var idFTcs = charIDToTypeID( "FTcs" );
var idQCSt = charIDToTypeID( "QCSt" );
var idQcsa = charIDToTypeID( "Qcsa" );
desc2.putEnumerated( idFTcs, idQCSt, idQcsa );
var idOfst = charIDToTypeID( "Ofst" );
var desc3 = new ActionDescriptor();
var idHrzn = charIDToTypeID( "Hrzn" );
var idPxl = charIDToTypeID( "#Pxl" );
desc3.putUnitDouble( idHrzn, idPxl, 0.000000 );
var idVrtc = charIDToTypeID( "Vrtc" );
var idPxl = charIDToTypeID( "#Pxl" );
desc3.putUnitDouble( idVrtc, idPxl, 0.013677 );
var idOfst = charIDToTypeID( "Ofst" );
desc2.putObject( idOfst, idOfst, desc3 );
var idWdth = charIDToTypeID( "Wdth" );
var idPrc = charIDToTypeID( "#Prc" );
desc2.putUnitDouble( idWdth, idPrc, 86.486860 );
var idHght = charIDToTypeID( "Hght" );
var idPrc = charIDToTypeID( "#Prc" );
desc2.putUnitDouble( idHght, idPrc, -88.215838 );
var idSkew = charIDToTypeID( "Skew" );
var desc4 = new ActionDescriptor();
var idHrzn = charIDToTypeID( "Hrzn" );
var idAng = charIDToTypeID( "#Ang" );
desc4.putUnitDouble( idHrzn, idAng, 0.033079 );
var idVrtc = charIDToTypeID( "Vrtc" );
var idAng = charIDToTypeID( "#Ang" );
desc4.putUnitDouble( idVrtc, idAng, 0.000000 );
var idPnt = charIDToTypeID( "Pnt " );
desc2.putObject( idSkew, idPnt, desc4 );
var idAngl = charIDToTypeID( "Angl" );
var idAng = charIDToTypeID( "#Ang" );
desc2.putUnitDouble( idAngl, idAng, -170.957285 );
executeAction( idTrnf, desc2, DialogModes.NO );
<强> FYI 强>
String location = dbHelper.getLocation(l).toString();
您应该在 public String getLocation(long id)
{
SQLiteDatabase db = this.getWritableDatabase();
String get_LOCATION = "";
String last_query = "SELECT " + LOCATION + " FROM " + TABLE_NAME + " WHERE " + _id + " = '" + id + "'";
Cursor c = db.rawQuery(last_query, null);
if (c != null && c.moveToFirst())
{
get_LOCATION = c.getString(0); // Return Value
}
db.close();
return get_LOCATION;
}
部分中传递正确的 PARAMETER
。确保 getLocation()
包含正确的 ID 。
答案 1 :(得分:0)
使用此
更改ListView
OnitemClick
方法代码
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
if(cursor.getCount()>0){
cursor.moveToPosition(i);
Intent intent = new Intent(MainActivity.this, EditData.class);
intent.putExtra("Location", cursor.getString(cursor.getColumnIndex(DBHelper.LOCATION))));
intent.putExtra("Date", cursor.getString(cursor.getColumnIndex(DBHelper.DATE))));
intent.putExtra("Not_at_homes", cursor.getString(cursor.getColumnIndex(DBHelper.NOTES))));
startActivity(intent);
}
}
});
答案 2 :(得分:0)
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
Cursor cursor = dbHelper.getLocation(l);
if(cursor.getCount()>0){
cursor.moveToPosition(i);
Intent intent = new Intent(MainActivity.this, EditData.class);
intent.putExtra("Location", cursor.getString(cursor.getColumnIndex(DBHelper.LOCATION))));
intent.putExtra("Date", cursor.getString(cursor.getColumnIndex(DBHelper.DATE))));
intent.putExtra("Not_at_homes", cursor.getString(cursor.getColumnIndex(DBHelper.NOTES))));
startActivity(intent);
}
}
});
在OnItemClick内部,当您单击特定项目时,将获取id并将其传递给方法getLocation以将数据作为游标返回。之后,您可以使用Cursor中的结果创建意图,然后开始您的活动。
您可能必须将对象dbHelper保留为最终,以便可以在onClickItem方法中访问它