zoukankan      html  css  js  c++  java
  • 作业十

    package com.example.demo01;
    
    import java.util.ArrayList;
    import java.util.List;
    import java.util.Map;
    
    import android.app.Activity;
    import android.content.ContentValues;
    import android.content.Context;
    import android.database.Cursor;
    import android.database.sqlite.SQLiteDatabase;
    import android.database.sqlite.SQLiteOpenHelper;
    import android.os.Bundle;
    import android.support.v7.app.ActionBarActivity;
    import android.text.TextUtils;
    import android.util.Log;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.BaseAdapter;
    import android.widget.Button;
    import android.widget.EditText;
    import android.widget.ListAdapter;
    import android.widget.ListView;
    import android.widget.TextView;
    import android.widget.Toast;
    
    public class MainActivity extends ActionBarActivity {
        private EditText etName, etPrice, etNumber;
        private ListView listView;
        private String name, price, number;
        private MyHelper myHelper;
        private SQLiteDatabase db;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main1111);
            myHelper = new MyHelper(this);
            init();
        }
    
        public void click(View v) {
            ContentValues values; // 创建ContentValues对象
            switch (v.getId()) {
            case R.id.button1:
                name = etPrice.getText().toString();
                price = etName.getText().toString();
                number = etNumber.getText().toString();
                db = myHelper.getWritableDatabase();
                values = new ContentValues();
                values.put("name", name); // 将数据添加到ContentValues对象
                values.put("price", price);
                values.put("number", number);
                db.insert("cart", null, values);
                db.close();
                Toast.makeText(this, "信息已添加", Toast.LENGTH_SHORT).show();
                break;
            case R.id.button2:
                Log.e("yanwenhua", "123");
                List<Commodity> list = new ArrayList();
                db = myHelper.getWritableDatabase();
                Cursor cursor = db
                        .query("cart", null, null, null, null, null, null);
                if (cursor.getCount() == 0) {
                    Toast.makeText(this, "没有数据", Toast.LENGTH_SHORT).show();
                } else {
                    while (cursor.moveToNext()) {
                        Commodity commodity = new Commodity();
                        int nameIndex = cursor.getColumnIndex("name");
                        int priceIndex = cursor.getColumnIndex("price");
                        int numberIndex = cursor.getColumnIndex("number");
                        String name = cursor.getString(nameIndex);
                        String price = cursor.getString(priceIndex);
                        String number = cursor.getString(numberIndex);
                        Log.e("yanwenhua",
                                "cursor.getCount();--" + cursor.getCount()
                                        + "name-" + name + "  " + price + "  "
                                        + number);
                        commodity.setName(name);
                        commodity.setPrice(price);
                        commodity.setNumber(number);
                        list.add(commodity);
                    }
                    MyBaseAdapter adapter = new MyBaseAdapter(MainActivity.this,
                            list);
                    listView.setAdapter(adapter);
                    adapter.notifyDataSetChanged();
                }
                cursor.close();
                db.close();
                break;
            case  R.id.button3:
                name = etPrice.getText().toString();
                price = etName.getText().toString();
                number = etNumber.getText().toString();
                db = myHelper.getWritableDatabase();
                values = new ContentValues();       // 要修改的数据
                values.put("number",number);
                values.put("price",price);
                db.update("cart", values, "name=?",
                        new String[]{name}); // 更新并得到行数
                db.close();
                Toast.makeText(this, "信息已修改", Toast.LENGTH_SHORT).show();
                break;
            case R.id.button4:
                db = myHelper.getWritableDatabase();
                db.delete("cart", null, null);
                List<Commodity> list2 = new ArrayList();
                MyBaseAdapter adapter = new MyBaseAdapter(MainActivity.this,list2);
                listView.setAdapter(adapter);
                adapter.notifyDataSetChanged();
                db.close();
                Toast.makeText(this, "信息已删除", Toast.LENGTH_SHORT).show();
                break;
            }
        }
    
        private void init() {
            setContentView(R.layout.activity_main1111);
            etName = (EditText) findViewById(R.id.editText2);
            etPrice = (EditText) findViewById(R.id.editText1);
            etNumber = (EditText) findViewById(R.id.editText3);
            listView = (ListView) findViewById(R.id.listView);
            Button add = (Button) findViewById(R.id.button1);
            Button query = (Button) findViewById(R.id.button2);
            Button update = (Button) findViewById(R.id.button3);
            Button delete = (Button) findViewById(R.id.button4);
        }
    
        class MyBaseAdapter extends BaseAdapter {
            private List<Commodity> list;
            private LayoutInflater layoutInflater;
            public MyBaseAdapter(Context context, List<Commodity> list){
                this.layoutInflater = LayoutInflater.from(context);
                this.list = list;
            }
            @Override
            public int getCount() {
                Log.e("yanwenhua","list.size()--"+list.size());
                return list.size();
            }
    
            @Override
            public Object getItem(int position) {
                return null;
            }
    
            @Override
            public long getItemId(int position) {
                return 0;
            }
    
            @Override
            public View getView(int position, View convertView, ViewGroup parent) {
                ViewHolder viewHolder;
                if (convertView==null){
                    convertView=layoutInflater.inflate(R.layout.list_item,null);
                    viewHolder=new ViewHolder(convertView);
                    convertView.setTag(viewHolder);
                }else {
                    viewHolder=(ViewHolder) convertView.getTag();
                }
                Commodity commodity = list.get(position);
                viewHolder.tv_name.setText("商品名称:"+commodity.getName());
                viewHolder.tv_price.setText("商品价格:"+commodity.getPrice());
                viewHolder.tv_number.setText("商品数量:"+commodity.getNumber());
                Log.e("yanwenhua","cartBean.getName()-"+commodity.getName()+"  "+commodity.getPrice()+"  "+commodity.getNumber());
                return convertView;
            }
            class ViewHolder{
                TextView tv_name;
                TextView tv_price;
                TextView tv_number;
                public ViewHolder(View view){
                    tv_name = (TextView) view.findViewById(R.id.textView1);
                    tv_price = (TextView) view.findViewById(R.id.textView2);
                    tv_number = (TextView) view.findViewById(R.id.textView3);
                }
            }
    
        }
    }
    package com.example.demo01;
    
    import android.support.v7.app.ActionBarActivity;
    import android.os.Bundle;
    import android.view.Menu;
    import android.view.MenuItem;
    
    public class Commodity {
    
        private String name;
           private String price;
           private String number;
    
           public String getName() {
               return name;
           }
    
           public void setName(String name) {
               this.name = name;
           }
    
           public String getPrice() {
               return price;
           }
    
           public void setPrice(String price) {
               this.price = price;
           }
    
           public String getNumber() {
               return number;
           }
    
           public void setNumber(String number) {
               this.number = number;
           }
    }
    package com.example.demo01;
    
    import android.support.v7.app.ActionBarActivity;
    import android.content.Context;
    import android.database.sqlite.SQLiteDatabase;
    import android.database.sqlite.SQLiteOpenHelper;
    import android.os.Bundle;
    import android.view.Menu;
    import android.view.MenuItem;
    
    public class MyHelper extends SQLiteOpenHelper {
    
        public MyHelper(Context context) {
            super(context, "shoppingcart.db", null, 1);
        }
    
        @Override
        public void onCreate(SQLiteDatabase db) {
            db.execSQL("CREATE TABLE cart(_id INTEGER PRIMARY KEY AUTOINCREMENT, name VARCHAR(20),  price VARCHAR(20), number VARCHAR(20))");
        }
    
        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        }
    }
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="#E6E6E6"
        android:orientation="vertical"
        android:padding="10dp">
        
       <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="15dp"
            android:background="@android:color/white"
            android:orientation="horizontal" >
    
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:padding="10dp"
                android:text="名称:"
                android:textColor="#000"
                android:textSize="20sp" />
    
            <EditText
                android:id="@+id/editText1"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginLeft="5dp"
                android:background="@null"
                android:maxLines="1"
                android:padding="10dp" />
        </LinearLayout>
    
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="15dp"
            android:background="@android:color/white"
            android:orientation="horizontal" >
    
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:padding="10dp"
                android:text="价格:"
                android:textColor="#000"
                android:textSize="20sp" />
    
            <EditText
                android:id="@+id/editText2"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginLeft="5dp"
                android:background="@null"
                android:maxLines="1"
                android:padding="10dp" />
        </LinearLayout>
    
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            android:background="@android:color/white"
            android:orientation="horizontal" >
    
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:padding="10dp"
                android:text="数量:"
                android:textColor="#000"
                android:textSize="20sp" />
    
            <EditText
                android:id="@+id/editText3"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginLeft="5dp"
                android:background="@null"
                android:maxLines="1"
                android:padding="10dp" />
        </LinearLayout>
    
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            android:orientation="horizontal" >
    
            <Button
                android:id="@+id/button1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:onClick="click"
                android:text="添加" />
    
            <Button
                android:id="@+id/button2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:onClick="click"
                android:text="查询" />
    
            <Button
                android:id="@+id/button3"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:onClick="click"
                android:text="修改" />
    
            <Button
                android:id="@+id/button4"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:onClick="click"
                android:text="删除" />
        </LinearLayout>
    
        <ListView
            android:id="@+id/listView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="#ffffff" >
        </ListView>
        
    </LinearLayout>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:padding="10dp">
    
        <TextView
            android:id="@+id/textView1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="15sp"/>
        <TextView
            android:id="@+id/textView2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="3dp"
            android:textSize="15sp"/>
        <TextView
            android:id="@+id/textView3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="3dp"
            android:textSize="15sp"/>
    
    </LinearLayout>

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  • 原文地址:https://www.cnblogs.com/shenxiaoqi/p/11850123.html
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