保存列表视图数据在sqlite数据库

Question

我必须在ListView中的每一行添加2个按钮。这些按钮是添加和删除。当用户选择其中一个按钮时，应该采取一些行动。 用户从datepicker.I中选择数据已创建保存按钮。当保存按钮被点击时，listview中的数据以及该日期必须保存在Sqlite数据库中。我该怎么办？ 以下是我的代码。

activity_main.xml 
<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:orientation="vertical" android:layout_width="match_parent" 
android:layout_height="match_parent"> 
    <ImageView 
     android:layout_width="90dp" 
     android:layout_height="50dp" 
     android:id="@+id/calender" 
     android:background="@drawable/calendar"/> 


    <EditText 
     android:layout_width="250dp" 
     android:layout_height="50dp" 
     android:hint="Enter Date..." 
     android:layout_centerHorizontal="true" 

     android:textColorHint="#992e28" 
     android:textSize="20sp" 
     android:textStyle="bold" 
     android:textAlignment="center" 
     android:layout_toRightOf="@+id/calender" 
     android:id="@+id/date"/> 

    <ListView 
    android:layout_width="match_parent" 
    android:layout_height="400dp" 
    android:id="@+id/my_listview"></ListView> 


    <Button 
     android:layout_width="90dp" 
     android:layout_height="40dp" 
     android:id="@+id/save" 
     android:text="Save"/> 
</LinearLayout> 


custom_list.xml 
<RelativeLayout 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" android:paddingLeft="@dimen/activity_horizontal_margin" 
android:paddingRight="@dimen/activity_horizontal_margin" 
android:paddingTop="@dimen/activity_vertical_margin" 
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity"> 

    <TextView 
    android:id="@+id/list_item_string" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_centerVertical="true" 
    android:layout_alignParentLeft="true" 
    android:paddingLeft="8dp" 
    android:textSize="18sp" 
    android:textStyle="bold" /> 

    <Button 
    android:id="@+id/delete_btn" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignParentRight="true" 
    android:layout_centerVertical="true" 
    android:layout_marginRight="5dp" 
    android:text="Delete" /> 

    <Button 
    android:id="@+id/add_btn" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_toLeftOf="@id/delete_btn" 
    android:layout_centerVertical="true" 
    android:layout_marginRight="10dp" 
    android:text="Add" /> 
</RelativeLayout> 

MainActivity.java 
package com.example.abc.lvtodb2; 
import android.app.Activity; 
import android.app.DatePickerDialog; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.view.Menu; 
import android.view.MenuItem; 
import android.view.View; 
import android.widget.Button; 
import android.widget.DatePicker; 
import android.widget.EditText; 
import android.widget.ImageView; 
import android.widget.ListView; 

import java.util.ArrayList; 
import java.util.Calendar; 

public class MainActivity extends Activity { 
    ListView lView; 
    Button insert; 

    EditText date; 
    ImageView cal; 

    DatePickerDialog datePickerDialog; 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     // initiate the date picker and a button 
     date = (EditText) findViewById(R.id.date); 
     cal = (ImageView) findViewById(R.id.calender); 
     // perform click event on edit text 
     cal.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       final Calendar c = Calendar.getInstance(); 
       int mYear = c.get(Calendar.YEAR);//current year 
       int mMonth = c.get(Calendar.MONTH); // current month 
       int mDay = c.get(Calendar.DAY_OF_MONTH); // current day 
       // date picker dialog 
       datePickerDialog = new DatePickerDialog(MainActivity.this, 
         new DatePickerDialog.OnDateSetListener() { 

          @Override 
          public void onDateSet(DatePicker view, int year, 
                int monthOfYear, int dayOfMonth) { 
           // set day of month , month and year value in the edit text 
           date.setText(dayOfMonth + "/" 
             + (monthOfYear + 1) + "/" + year); 

          } 
         }, mYear, mMonth, mDay); 
       datePickerDialog.show(); 
      } 


     }); 


     //generate list 
     ArrayList<String> list = new ArrayList<String>(); 
     list.add("item1"); 
     list.add("item2"); 
     list.add("item3"); 
     list.add("item4"); 
     list.add("item5"); 

     insert=(Button)findViewById(R.id.save); 

     //instantiate custom adapter 
     CustomAdapter adapter = new CustomAdapter(list,MainActivity.this); 

     //handle listview and assign adapter 
     lView = (ListView)findViewById(R.id.my_listview); 
     lView.setAdapter(adapter); 


    } 


} 


CustomAdapter.java 
package com.example.abc.lvtodb2; 

import android.content.Context; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.BaseAdapter; 
import android.widget.Button; 
import android.widget.ListAdapter; 
import android.widget.TextView; 
import android.widget.Toast; 

import java.util.ArrayList; 

/** 
* Created by ABC on 2/14/2017. 
*/ 
public class CustomAdapter extends BaseAdapter implements ListAdapter { 
    private ArrayList<String> list = new ArrayList<String>(); 
    private Context context; 

    public CustomAdapter(ArrayList<String> list, Context context) { 
     this.list = list; 
     this.context = context; 
    } 

    @Override 
    public int getCount() { 
     return list.size(); 
    } 

    @Override 
    public Object getItem(int pos) { 
     return list.get(pos); 
    } 

    @Override 
    public long getItemId(int pos) { 
     return 0; 

    } 

    @Override 
    public View getView(final int position, View convertView, ViewGroup parent) { 
     View view = convertView; 
     if (view == null) { 
      LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
      view = inflater.inflate(R.layout.custom_list, null); 
     } 

     //Handle TextView and display string from your list 
     TextView listItemText = (TextView)view.findViewById(R.id.list_item_string); 
     listItemText.setText(list.get(position)); 

     //Handle buttons and add onClickListeners 
     Button deleteBtn = (Button)view.findViewById(R.id.delete_btn); 
     Button addBtn = (Button)view.findViewById(R.id.add_btn); 

     deleteBtn.setOnClickListener(new View.OnClickListener(){ 
      @Override 
      public void onClick(View v) { 
       //do something 
       list.remove(position); //or some other task 
       notifyDataSetChanged(); 
      } 
     }); 
     addBtn.setOnClickListener(new View.OnClickListener(){ 
      @Override 
      public void onClick(View v) { 
       Toast.makeText(context,"Item added",Toast.LENGTH_SHORT).show(); 
       notifyDataSetChanged(); 
      } 
     }); 

     return view; 
    } 
} 

Answer 1

在你尝试编码之前，你必须学习很多Android的东西。

1. 了解如何在表格中创建，插入，更新和删除行。 SqliteOpenHelper类。
2. 开始使用游标Adaper
3. 尝试使用ViewHolder模式在getView方法缓存您的意见
4. 您可能必须根据您的单击事件中插入/更新项目。

我建议您搜索谷歌或stackoverflow中的每个主题，看看如何做。没有人会帮你编写自己的代码。你必须这样做。

最佳资源：developer.android.com