数据库删除，存储

布局主要分两个

其中主布局是

<EditText
android:id="@+id/yf_input"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:hint=""
android:textSize="25sp"
android:textColor="#FF0000"/>

<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent">

<Button
android:id="@+id/yf_add"
android:layout_width="120dp"
android:layout_height="50dp"
android:layout_weight="1"
android:text="增加一条记录"
android:textSize="25sp"
android:textColor="#FF0000"
android:background="@android:color/transparent"
android:onClick="onClick"/>

<Button
android:id="@+id/yf_delete"
android:layout_width="120dp"
android:layout_height="50dp"
android:layout_weight="1"
android:text="删除一条记录"
android:textSize="25sp"
android:textColor="#FF0000"
android:background="@android:color/transparent"
android:onClick="onClick"/>


</LinearLayout>

<ListView
android:id="@+id/yf_listview"
android:layout_width="match_parent"
android:layout_height="match_parent">

</ListView>
</LinearLayout>

---

对于ListView的布局定义则是

<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:textColor="#FF0000"
android:textSize="25sp"
android:id="@+id/yf_name"/>

</LinearLayout>

---

自定义的adapter

package com.example.kimdemon.sqllite;

import android.content.Context;
import android.database.Cursor;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CursorAdapter;
import android.widget.TextView;


public class dapter extends CursorAdapter{

public dapter(Context context,Cursor cursor){
    super(context,cursor,0);
}
@Override
public View newView(Context context, Cursor cursor, ViewGroup viewGroup) {
    return LayoutInflater.from(context).inflate(R.layout.list,viewGroup,false);
}

@Override
public void bindView(View view, Context context, Cursor cursor) {
    TextView name = (TextView) view.findViewById(R.id.yf_name);
    name.setText(cursor.getString(cursor.getColumnIndex("name")));

}
}

---

数据库的创建和打开

package com.example.kimdemon.sqllite;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class Create extends SQLiteOpenHelper {
private String sql="create table student(_id integer primary key autoincrement,"
+"name text not null ,classmate text not null,age integer)";


public Create(Context context){
   super(context,"ManagerInfo",null,1);
}


@Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {

}

public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
    sqLiteDatabase.execSQL("drop table if exists person");
    onCreate(sqLiteDatabase);
}
}

---

数据库的操作

package com.example.kimdemon.sqllite;

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



public class Manager {
private Create create;
private SQLiteDatabase sqLiteDatabase;


public Manager(Context context){
create = new Create(context);

}
 public void insert(String name){
 sqLiteDatabase = create.getWritableDatabase();
 String sql = "insert into person(name) values('"+name+"')";
 sqLiteDatabase.execSQL(sql);


 }

 public Cursor selectAll(){
 sqLiteDatabase = create.getReadableDatabase();
 Cursor cursor = sqLiteDatabase.query("manager",null,null,null,null,null,null);
 return cursor;
 }

 public void delete(String id){
 sqLiteDatabase = create.getWritableDatabase();
 String sql = "delete person where _id="+String.valueOf(id);
 sqLiteDatabase.execSQL(sql);
}

}

---

主Java代码则是

package com.example.kimdemon.sqllite;

import android.database.Cursor;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.EditText;
import android.widget.ListView;

public class MainActivity extends AppCompatActivity {
private EditText yf_input;
private ListView yf_listview;
private dapter dapter;
private Create create;
private Manager manager;
private Cursor cursor;


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

yf_input = (EditText) findViewById(R.id.yf_input);
yf_listview = (ListView) findViewById(R.id.yf_listview);

manager = new Manager(this);
    cursor = manager.selectAll();
    if (cursor != null ){
        dapter = new dapter(MainActivity.this,cursor);
        yf_listview.setAdapter(dapter);
    }
}

public void onClick(View view){
    switch (view.getId()){
        case R.id.yf_add:
            String name = yf_input.getText().toString();
            manager.insert(name);
            cursor = manager.selectAll();
            if (cursor != null){
                dapter = new dapter(this,cursor);
                yf_listview.setAdapter(dapter);
            }
            break;
        case R.id.yf_delete:
if (cursor != null){
    if (cursor.moveToFirst()){
        manager.delete(cursor.getString(cursor.getColumnIndex("_id")));
        cursor = manager.selectAll();
    }
}

            dapter = new dapter(this,cursor);
            yf_listview.setAdapter(dapter);
            break;

    }
}
}