如何使用 spinners 和 seekers 搜索 Sqlite 数据库？

Question

我的主 activity 上有一组微调器和搜索栏，我想使用那里的用户输入来查询 sql-lite 数据库，return 我的结果 Activity。请你帮我解决这个问题。

我查询的数据库在DatabaseAccess.javaClass

这是我的activity_main.xml

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:background="#f5f5f5">
    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="@color/colorPrimary"
        android:elevation="4dp"
app:titleTextColor="#FFFFFF"
        android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
        app:popupTheme="@style/ThemeOverlay.AppCompat.Light"/>

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        >



        <android.support.v7.widget.CardView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_margin="16dp"
            android:elevation="4dp"

            >
            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical"
                android:padding="16dp">

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:padding="16dp"
                    android:paddingTop="16dp"
                    android:textSize="16sp"

                    android:text="Hunger Level" />
                <Spinner
                    android:id="@+id/hunger_spinner"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"


                    android:padding="16dp"

                    >

                </Spinner>
                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:padding="16dp"
                    android:textSize="16sp"
                    android:text="Cuisine" />
                <Spinner
                    android:id="@+id/cuisine_spinner"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"


                    android:padding="16dp"

                    >

                </Spinner>
                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:padding="16dp"
                    android:textSize="16sp"
                    android:text="Preparation Time" />
                <Spinner
                    android:id="@+id/time_spinner"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"


                    android:padding="16dp"

                    >

                </Spinner>
                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:padding="16dp"
                    android:textSize="16sp"
                    android:text="Course" />
                <Spinner
                    android:id="@+id/course_spinner"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"


                    android:padding="16dp"

                    >

                </Spinner>

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Salty"
                    android:padding="16dp"
                    android:textSize="16sp"
                    />
                <TextView
                    android:id="@+id/howSalty"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center_horizontal"
                    />

                <SeekBar
                    android:id="@+id/salty"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:thumbTint="@color/colorAccent"
                    android:progressTint="@color/colorAccent"
                    android:max="2"
                    android:progress="1"
                    />
                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Sweet"
                    android:padding="16dp"
                    android:textSize="16sp"/>
                <TextView
                    android:id="@+id/howSweet"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center_horizontal"/>
                <SeekBar
                    android:thumbTint="@color/colorAccent"
                    android:progressTint="@color/colorAccent"
                    android:id="@+id/sweet"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:max="2"
                    android:progress="1"
                    />


                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Spicy"
                    android:padding="16dp"
                    android:textSize="16sp"/>

                <TextView
                    android:id="@+id/howSpicy"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center_horizontal"
                    />
                <SeekBar
                    android:thumbTint="@color/colorAccent"
                    android:progressTint="@color/colorAccent"
                    android:id="@+id/spicy"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:max="2"
android:progress="1"

                    />

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"

                    android:padding="16dp"
                    android:text="Special Requirements"

                    android:textSize="16sp" />

                <GridLayout
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"

                    android:layout_margin="16dp"
                    android:columnCount="2"
                    android:rowCount="3">



                    <CheckBox
                        android:layout_width="wrap_content"
                        android:buttonTint="@color/colorAccent"
                        android:layout_height="wrap_content"
                        android:text="Dairy Free"
                        android:textSize="16sp" />

                    <CheckBox
                        android:layout_width="wrap_content"

                        android:buttonTint="@color/colorAccent"
                        android:layout_height="wrap_content"
                        android:text="Nut Free"
                        android:textSize="16sp" />

                    <CheckBox
                        android:layout_width="wrap_content"
                        android:buttonTint="@color/colorAccent"
                        android:layout_height="wrap_content"
                        android:text="Egg Free"
                        android:textSize="16sp"
                        />

                    <CheckBox
                        android:layout_width="wrap_content"
                        android:buttonTint="@color/colorAccent"
                        android:layout_height="wrap_content"
                        android:text="Vegetarian"
                        android:textSize="16sp" />
                </GridLayout>
                <Button
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"

                    android:layout_margin="16dp"
                    android:onClick="go"

                    android:text="go" />
            </LinearLayout>
        </android.support.v7.widget.CardView>

    </ScrollView>
</LinearLayout>

这是MainActivity.java

package com.example.rcadit.foodgenie;

import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.SeekBar;
import android.widget.Spinner;
import android.widget.TextView;


import butterknife.ButterKnife;
import butterknife.InjectView;




public class MainActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener {
    private static final String TAG = "MyActivity";


    public void onNothingSelected(AdapterView<?> parent) {
        // Another interface callback
    }

    Toolbar toolbar;
    @InjectView(R.id.salty)
    SeekBar salty;
    private String hungerValue;
    private String cuisineValue;
    private String prepValue;
    private String courseValue;



    @Override
    protected void onCreate(Bundle savedInstanceState) {


        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.inject(this);
        initToolBar();
        saltySlider();
        spicySlider();
        sweetSlider();


        Spinner hunger_spinner = (Spinner) findViewById(R.id.hunger_spinner);
        hunger_spinner.setOnItemSelectedListener(this);
            ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
                R.array.hunger_level, android.R.layout.simple_spinner_item);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        hunger_spinner.setAdapter(adapter);



        Spinner cuisine_spinner = (Spinner) findViewById(R.id.cuisine_spinner);
        cuisine_spinner.setOnItemSelectedListener(this);
                         ArrayAdapter<CharSequence> adapter2 = ArrayAdapter.createFromResource(this,
                     R.array.cuisine, android.R.layout.simple_spinner_item);
                                adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
                cuisine_spinner.setAdapter(adapter2);

        Spinner prep_spinner = (Spinner) findViewById(R.id.time_spinner);
        prep_spinner.setOnItemSelectedListener(this);
                ArrayAdapter<CharSequence> adapter3 = ArrayAdapter.createFromResource(this,
                R.array.preparation_time, android.R.layout.simple_spinner_item);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        prep_spinner.setAdapter(adapter3);

        Spinner course_spinner = (Spinner) findViewById(R.id.course_spinner);
        course_spinner.setOnItemSelectedListener(this);
                ArrayAdapter<CharSequence> adapter4 = ArrayAdapter.createFromResource(this,
                R.array.course, android.R.layout.simple_spinner_item);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
course_spinner.setAdapter(adapter4);


}

    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
        Spinner spinner = (Spinner) parent;
        // On selecting a spinner item
        String value = parent.getItemAtPosition(position).toString();
        if ("Low".equals(value) ) {
            hungerValue = "1";

            SharedPreferences.Editor editor = prefs.edit();
            editor.putString("hungerData", hungerValue); //InputString: from the EditText
            editor.apply();
        }
        if ("Medium".equals(value) ) {
            hungerValue = "2";

            SharedPreferences.Editor editor = prefs.edit();
            editor.putString("hungerData", hungerValue); //InputString: from the EditText
            editor.apply();
        }
        if ("High".equals(value) ) {
            hungerValue = "3";

            SharedPreferences.Editor editor = prefs.edit();
            editor.putString("hungerData", hungerValue); //InputString: from the EditText
            editor.apply();
        }
        if ("Under 10 mins".equals(value) ) {
            prepValue = "< 10";

            SharedPreferences.Editor editor = prefs.edit();
            editor.putString("prepData", prepValue); //InputString: from the EditText
            editor.apply();
        }
        if ("No Preparation".equals(value) ) {
            prepValue = " = 0";

            SharedPreferences.Editor editor = prefs.edit();
            editor.putString("prepData", prepValue); //InputString: from the EditText
            editor.apply();
        }
        if ("Under 20 mins".equals(value) ) {
            prepValue = "< 20";

            SharedPreferences.Editor editor = prefs.edit();
            editor.putString("prepData", prepValue); //InputString: from the EditText
            editor.apply();
        }
        if ("Under 30 mins".equals(value) ) {
            prepValue = "< 30";

            SharedPreferences.Editor editor = prefs.edit();
            editor.putString("prepData", prepValue); //InputString: from the EditText
            editor.apply();
        }
        if ("Over 30 mins".equals(value) ) {
            prepValue = "> 30";

            SharedPreferences.Editor editor = prefs.edit();
            editor.putString("prepData", prepValue); //InputString: from the EditText
            editor.apply();
        }
        if(spinner.getId() == R.id.cuisine_spinner)
        {
            cuisineValue = value;

            SharedPreferences.Editor editor = prefs.edit();
            editor.putString("cuisineData", cuisineValue); //InputString: from the EditText
            editor.apply();
        }

        if(spinner.getId() == R.id.course_spinner)
        {
            courseValue = value;

            SharedPreferences.Editor editor = prefs.edit();
            editor.putString("courseData", courseValue); //InputString: from the EditText
            editor.apply();
        }

        Log.d(TAG, "onItemSelected: " + value + " " + courseValue+ " "+ cuisineValue + " "+ prepValue + " "+ hungerValue);

    }



    public String getHungerValue(){
        return hungerValue;
    }


    public String getCuisineValue(){
        return cuisineValue;
    }


    public String getPrepValue(){
        return prepValue;
    }


    public String getCourseValue(){
        return courseValue;
    }


    private void saltySlider() {
        salty.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            int progressChanged = 0;

            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                progressChanged = progress * 50;
            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {
            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
                if (progressChanged < 100 / 3) {
                    TextView textView = (TextView) findViewById(R.id.howSalty);
                    textView.setHint("Not Salty");

                }
                if (progressChanged > 100 / 3 & progressChanged < 2 * (100 / 3)) {
                    TextView textView = (TextView) findViewById(R.id.howSalty);
                    textView.setHint("Salty");
                }
                if (progressChanged > 2 * (100 / 3)) {
                    TextView textView = (TextView) findViewById(R.id.howSalty);
                    textView.setHint("Very Salty");
                }
            }
        });
    }

    private void sweetSlider() {
        SeekBar sweet = (SeekBar) findViewById(R.id.sweet);
        sweet.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            int progressChanged = 0;

            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                progressChanged = progress * 50;
            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {
            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
                if (progressChanged < 100 / 3) {
                    TextView textView = (TextView) findViewById(R.id.howSweet);
                    textView.setHint("Not Sweet");

                }
                if (progressChanged > 100 / 3 & progressChanged < 2 * (100 / 3)) {
                    TextView textView = (TextView) findViewById(R.id.howSweet);
                    textView.setHint("Sweet");
                }
                if (progressChanged > 2 * (100 / 3)) {
                    TextView textView = (TextView) findViewById(R.id.howSweet);
                    textView.setHint("Very Sweet");
                }
            }
        });
    }

    private void spicySlider() {
        SeekBar spicy = (SeekBar) findViewById(R.id.spicy);
        spicy.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            int progressChanged = 0;

            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                progressChanged = progress * 50;
            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {
            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
                if (progressChanged < 100 / 3) {
                    TextView textView = (TextView) findViewById(R.id.howSpicy);
                    textView.setHint("Not Spicy");

                }
                if (progressChanged > 100 / 3 & progressChanged < 2 * (100 / 3)) {
                    TextView textView = (TextView) findViewById(R.id.howSpicy);
                    textView.setHint("Spicy");
                }
                if (progressChanged > 2 * (100 / 3)) {
                    TextView textView = (TextView) findViewById(R.id.howSpicy);
                    textView.setHint("Very Spicy");
                }
            }
        });
    }

    public void initToolBar() {

        toolbar = (Toolbar) findViewById(R.id.toolbar);

        toolbar.setTitle(R.string.app_name);


        setSupportActionBar(toolbar);
    }
    public void go(View view)
    {
        Intent intent = new Intent(MainActivity.this, ResultActivity.class);
        startActivity(intent);
    }



}

DatabaseAccess.java

package com.example.rcadit.foodgenie;

/**
 * Created by rcadi on 8/22/2016.
 */


import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

import java.util.ArrayList;
import java.util.List;

public class DatabaseAccess {
    private SQLiteOpenHelper openHelper;
    private SQLiteDatabase database;
    private static DatabaseAccess instance;

    /**
     * Private constructor to aboid object creation from outside classes.
     *
     * @param context
     */
    private DatabaseAccess(Context context) {
        this.openHelper = new DatabaseOpenHelper(context);
    }

    /**
     * Return a singleton instance of DatabaseAccess.
     *
     * @param context the Context
     * @return the instance of DabaseAccess
     */
    public static DatabaseAccess getInstance(Context context) {
        if (instance == null) {
            instance = new DatabaseAccess(context);
        }
        return instance;
    }

    /**
     * Open the database connection.
     */
    public void open() {
        this.database = openHelper.getWritableDatabase();
    }

    /**
     * Close the database connection.
     */
    public void close() {
        if (database != null) {
            this.database.close();
        }
    }

    /**
     * Read all quotes from the database.
     *
     * @return a List of quotes
     */
    public List<String> getResult() {
        List<String> list = new ArrayList<>();
        Cursor cursor = database.rawQuery("SELECT foodName from foodDB ", null);
        cursor.moveToFirst();
        while (!cursor.isAfterLast()) {
            list.add(cursor.getString(0));
            cursor.moveToNext();
        }
        cursor.close();
        return list;
    }
}

数据库助手

package com.example.rcadit.foodgenie;

/**
 * Created by rcadi on 8/22/2016.
 */

import android.content.Context;

import com.readystatesoftware.sqliteasset.SQLiteAssetHelper;

public class DatabaseOpenHelper extends SQLiteAssetHelper {
    private static final String DATABASE_NAME = "foodfile.sqlite";
    private static final int DATABASE_VERSION = 1;

    public DatabaseOpenHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }
}

ResultsActivity.java

package com.example.rcadit.foodgenie;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import com.example.rcadit.foodgenie.R;

import java.util.List;

import static com.example.rcadit.foodgenie.R.id.toolbar;

public class ResultActivity extends AppCompatActivity {
    Toolbar toolbar;






        private ListView listView;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_result);
            initToolBar();
            this.listView = (ListView) findViewById(R.id.listView);
            DatabaseAccess databaseAccess = DatabaseAccess.getInstance(this);
            databaseAccess.open();
            List<String> results = databaseAccess.getResult();
            databaseAccess.close();

            ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, results);
            this.listView.setAdapter(adapter);
        }
    public void initToolBar() {

        toolbar = (Toolbar) findViewById(R.id.toolbar);

        toolbar.setTitle(R.string.app_name);


        setSupportActionBar(toolbar);
    }
    }

最后 activity_results

<?xml version="1.0" encoding="utf-8"?>


<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="@color/colorPrimary"
        android:elevation="4dp"
        app:titleTextColor="#FFFFFF"
        android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
        app:popupTheme="@style/ThemeOverlay.AppCompat.Light"/>
        <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
            xmlns:tools="http://schemas.android.com/tools"
            android:layout_width="match_parent"
            android:layout_height="match_parent"

            tools:context="com.example.rcadit.foodgenie.ResultActivity">

            <android.support.v7.widget.CardView
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_margin="16dp"
                android:elevation="4dp"

                >

            <ListView
                android:id="@+id/listView"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_gravity="center" />
            </android.support.v7.widget.CardView>

        </FrameLayout>

    </LinearLayout>

谢谢

Answer 1

我猜您在将数据传递到新 activity 然后查询该数据时遇到了问题？

最简单的方法是将 Extras 添加到意图中，然后将它们拉出到新的 activity:

public void go(View view)
{
    Intent intent = new Intent(MainActivity.this, ResultActivity.class);
    intent.putExtra(ResultsActivity.HungerValueTag, hungerValue);
    intent.putExtra(ResultsActivity.CuisineValueTag, cuisineValue);
    intent.putExtra(ResultsActivity.PrepValueTag, prepValue);
    intent.putExtra(ResultsActivity.CourseValueTag, CourseValue);

    startActivity(intent);
}

在下一个 activity 中，从 Intent Extras 中提取值，然后将值传递给 getResult() 方法。

ResultsActivity.java:

 public static final String HungerValueTag = "HungerValue";
 // Add the same for the other three..

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        ...

        String hunger = getIntent().getStringValue(HungerValueTag);
        String cuisine = getIntent().getStringValue(CuisineValueTag);
        // get the other two


        List<String> results = databaseAccess.getResult(hunger, cuisine, prep, course);

        ...
    }

我不知道你的列名或类型是什么，所以我在这里猜测。您还需要确保 sql 有效，可能需要在字符串周围添加单引号。

DatabaseAccess.java

 public List<String> getResult(String hunger, String cuisine, String prep, String course) {
    List<String> list = new ArrayList<>();
    String query = String.format("SELECT foodName from foodDB where hunger = %s and cuisine = %s and prep = %s and course = %s", hunger, cuisine, prep, course);

    Cursor cursor = database.rawQuery(query, null);
    cursor.moveToFirst();
    while (!cursor.isAfterLast()) {
        list.add(cursor.getString(0));
        cursor.moveToNext();
    }
    cursor.close();
    return list;
}

我一般不再像这样构建 SQL，我总是使用 ORM，用对象处理数据库。

如何使用 spinners 和 seekers 搜索 Sqlite 数据库？

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