0
試圖看看其他線程，但似乎不同我似乎已經編碼我的類（基於http://go.developer.ebay.com/devzone/articles/build-product-database-zxing-and-sqlite-android）如何從android數據庫sqlite中讀取數據？
想要從字母順序讀取基於'標題'列的數據庫中的數據。
或者如果有辦法用當前日期戳記輸入數據，然後通過日期訂購當前項目？
AddProduct.java
package com.example.foodcalculator;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import com.example.foodcalculator.Homepage.ProductData;
public class AddItem extends Activity implements OnClickListener {
private static final int REQUEST_BARCODE = 0;
private static final ProductData mProductData = new ProductData();
EditText mBarcodeEdit;
EditText mTitleEdit;
EditText mQuantityEdit;
private Button mScanButton;
private Button mAddButton;
// private ProductDatabase mProductDb;
ProductDatabase mProductDb;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.add_product);
mBarcodeEdit = (EditText) findViewById(R.id.barcodeEdit);
mTitleEdit = (EditText) findViewById(R.id.titleEdit);
mQuantityEdit = (EditText) findViewById(R.id.quantityEdit);
mScanButton = (Button) findViewById(R.id.scanButton);
mScanButton.setOnClickListener(this);
mAddButton = (Button) findViewById(R.id.addButton);
mAddButton.setOnClickListener(this);
mProductDb = new ProductDatabase(this);
}
public void onClick(View v) {
// TODO Auto-generated method stub
switch (v.getId()) {
case R.id.scanButton:
Intent intent = new Intent("com.google.zxing.client.android.SCAN");
intent.putExtra("SCAN_MODE", "PRODUCT_MODE");
startActivityForResult(intent, REQUEST_BARCODE);
break;
case R.id.addButton:
String barcode = mBarcodeEdit.getText().toString();
String title = mTitleEdit.getText().toString();
String quantity = mQuantityEdit.getText().toString();
String errors = validateFields(barcode, title, quantity);
if (errors.length() > 0) {
showInfoDialog(this, "Please fix errors", errors);
} else {
mProductData.barcode = barcode;
mProductData.title = title;
mProductData.quantity = Double.valueOf(quantity);
mProductDb.insert(mProductData);
showInfoDialog(this, "Success", "Product saved successfully");
resetForm();
}
break;
}
}
private void showInfoDialog(Context context, String title,
String information) {
new AlertDialog.Builder(context).setMessage(information)
.setTitle(title)
.setPositiveButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
}).show();
}
private void resetForm() {
// TODO Auto-generated method stub
mBarcodeEdit.getText().clear();
mTitleEdit.getText().clear();
mQuantityEdit.getText().clear();
}
public void onActivityResult(int requestCode, int resultCode, Intent intent) {
if (requestCode == REQUEST_BARCODE) {
if (resultCode == RESULT_OK) {
String barcode = intent.getStringExtra("SCAN_RESULT");
mBarcodeEdit.setText(barcode);
} else if (resultCode == RESULT_CANCELED) {
finish();
}
}
}
private static String validateFields(String barcode, String title,
String quantity) {
StringBuilder errors = new StringBuilder();
if (barcode.matches("^\\s*$")) {
errors.append("Barcode required\n");
}
if (title.matches("^\\s*$")) {
errors.append("Title required\n");
}
if (!quantity.matches("^-?\\d+(.\\d+)?$")) {
errors.append("Need numeric quantity\n");
}
return errors.toString();
}
}
ProductDatabase.java
package com.example.foodcalculator;
import com.example.foodcalculator.Homepage.ProductData;
import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class ProductDatabase {
private static final String PRODUCT_TABLE = "products";
private static final String DATABASE_NAME = "foodcalculator.db";
private static final int DATABASE_VERSION = 1;
private SQLiteDatabase db;
private static class ProductDatabaseHelper extends SQLiteOpenHelper {
private static final String TAG = null;
public ProductDatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase db) {
StringBuilder sql = new StringBuilder();
sql.append("create table ").append(PRODUCT_TABLE).append("( ")
.append(" _id integer primary key,")
.append(" barcode text,").append(" title text,")
.append(" quantity number").append(") ");
db.execSQL(sql.toString());
Log.d(TAG, PRODUCT_TABLE + "table created");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("drop table if exists " + PRODUCT_TABLE);
onCreate(db);
}
}
public ProductDatabase(Context context) {
ProductDatabaseHelper helper = new ProductDatabaseHelper(context);
db = helper.getWritableDatabase();
}
public boolean insert(ProductData product) {
ContentValues vals = new ContentValues();
vals.put("barcode", product.barcode);
vals.put("title", product.title);
vals.put("quantity", product.quantity);
return db.insert(PRODUCT_TABLE, null, vals) != -1;
}
}
這是我目前的項目類，我想告訴我的所有數據項，但我只想要展示2欄信息 - 標題和數量。按標題排序。
CurrentItems.java
package com.example.foodcalculator;
import java.util.ArrayList;
import java.util.Scanner;
import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
public class CurrentItems extends Activity {
private final String DATABASE_NAME = "foodcalculator.db";
private final String PRODUCT_TABLE = "products";
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ArrayList<String> results = new ArrayList<String>();
SQLiteDatabase foodDB = null;
try {
foodDB = this.openOrCreateDatabase(DATABASE_NAME, MODE_PRIVATE,
null);
foodDB.execSQL("CREATE TABLE IF NOT EXISTS " + PRODUCT_TABLE
+ " (barcode String, format String,"
+ " title String, price Double;");
foodDB.execSQL("INSERT INTO " + PRODUCT_TABLE
+ " Values ('564565645665','Beans',1.5);");
Cursor c = foodDB.rawQuery("SELECT FROM " + PRODUCT_TABLE, null);
if (c != null) {
if (c.moveToFirst()) {
do {
String title = c.getString(c.getColumnIndex("title"));
Double quantity = c.getDouble(c
.getColumnIndex("Quantity"));
results.add("" + title + ",Quantity: " + quantity);
} while (c.moveToNext());
}
}
this.setListAdapter(new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, results));
} catch (SQLiteException se) {
Log.e(getClass().getSimpleName(),
"Could not create or open the database");
} finally {
if (foodDB != null)
foodDB.execSQL("DELETE FROM " + PRODUCT_TABLE);
foodDB.close();
}
super.onCreate(savedInstanceState);
setContentView(R.layout.current_inventory);
final Button scanButton = (Button) findViewById(R.id.addButton);
final Button editInventoryButton = (Button) findViewById(R.id.editItemCurrent);
scanButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// TODO Auto-generated method stub
Intent intent = new Intent(view.getContext(), Scanner.class);
startActivity(intent);
}
});
editInventoryButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// TODO Auto-generated method stub
Intent intent = new Intent(view.getContext(), EditItems.class);
startActivity(intent);
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main, menu);
return super.onCreateOptionsMenu(menu);
}
}
基於當前的代碼我在得到一個錯誤：
this.setListAdapter(new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, results));
「的方法setListAdapter（ArrayAdapter）是未定義的類型CurrentItems CurrentItems。 java「
/FoodCalculator/src/com/example/foodcalculator line 56 Java問題
試圖從活動作如下修改ListView的，但其產生的一些錯誤
public class CurrentItems extends Activity
public class CurrentItems extends ListView
的希望得到任何幫助！
編輯：Main類添加
package com.example.foodcalculator;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class Homepage extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.homepage);
final Button addButton = (Button) findViewById(R.id.scanner);
final Button editInventoryButton = (Button) findViewById(R.id.editItem);
final Button currentInventoryButton = (Button) findViewById(R.id.currentItems);
final Button settingsButton = (Button) findViewById(R.id.settings);
addButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View view) {
/* startActivity(new Intent(Homepage.this, AddProduct.class)); */
Intent intent = new Intent(view.getContext(), AddItem.class);
startActivity(intent);
}
});
/*
* currentInventoryButton.setOnClickListener(new View.OnClickListener()
* {
*
* @Override public void onClick(View view) { // TODO Auto-generated
* method stub Intent intent = new Intent(view.getContext(),
* CurrentInventory.class); startActivity(intent); } });
*/
editInventoryButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// TODO Auto-generated method stub
Intent intent = new Intent(view.getContext(), EditItems.class);
startActivity(intent);
}
});
settingsButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// TODO Auto-generated method stub
Intent intent = new Intent(view.getContext(), Settings.class);
startActivity(intent);
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main, menu);
return super.onCreateOptionsMenu(menu);
}
static final class ProductData {
String barcode;
String title;
Double quantity;
}
}
你能張貼foodcalculator的代碼？有錯誤似乎沒有涉及插入或排序數據庫中的項目。 – soundsofpolaris
已根據要求添加到主帖 – tagz2712