Android高级-Android操作SQL数据管理，增删改查
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已经学了好几天SQL了，昨天刚接触到android操作SQL数据库，晚上老师留了一个作业，效果图如下
分别是，主界面，和修改，添加，以及删除界面
首先我们先来实现布局 MainActivity.xml
1 <?xml version="1.0" encoding="utf-8"?> 2 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" 4 android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" 5 6 tools:context="wuxianedu.com.sqllistview.MainActivity"> 7 8 <ListView android:id="@+id/lv_liebiao" 9 android:layout_width="match_parent" 10 android:layout_height="match_parent"> 11 </ListView> 12 </RelativeLayout>
布局很简洁，只有一个ListView,
下面是List列表的item布局
1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 android:orientation="horizontal" android:layout_width="match_parent" 4 android:layout_height="match_parent"> 5 <LinearLayout android:layout_width="0dp" 6 android:layout_height="wrap_content" 7 android:layout_weight="5"> 8 <TextView android:id="@+id/tv_name" 9 android:layout_width="0dp" android:layout_gravity="center_vertical" 10 android:layout_height="wrap_content" 11 android:text="aaa" android:layout_weight="1" 12 android:gravity="center"/> 13 14 <TextView android:id="@+id/tv_age" 15 android:layout_width="wrap_content" 16 android:layout_height="wrap_content" android:layout_gravity="center_vertical" 17 android:text="aaa" android:layout_weight="1" 18 android:gravity="center"/> 19 <TextView android:id="@+id/tv_sex" 20 android:layout_width="wrap_content" 21 android:layout_height="wrap_content" android:layout_gravity="center_vertical" 22 android:text="aaa" android:layout_weight="1" 23 android:gravity="center"/> 24 </LinearLayout> 25 <Button android:id="@+id/but_name" 26 android:layout_width="0dp" 27 android:layout_height="wrap_content" 28 android:text="修改" android:layout_weight="1" 29 android:gravity="center"/> 30 31 <Button android:id="@+id/but_delete" 32 android:layout_width="0dp" 33 android:layout_height="wrap_content" 34 android:text="删除" android:layout_weight="1" 35 android:gravity="center"/> 36 </LinearLayout>
之后是修改和添加界面的XML代码
UpdateActivity.xml
1 <?xml version="1.0" encoding="utf-8"?> 2 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 xmlns:tools="http://schemas.android.com/tools" 4 android:layout_width="match_parent" 5 android:orientation="vertical" 6 android:layout_height="match_parent" 7 android:paddingBottom="@dimen/activity_vertical_margin" 8 android:paddingLeft="@dimen/activity_horizontal_margin" 9 android:paddingRight="@dimen/activity_horizontal_margin" 10 android:paddingTop="@dimen/activity_vertical_margin" 11 tools:context="wuxianedu.com.sqllistview.UpdateActivity"> 12 13 <EditText android:id="@+id/ed_name" 14 android:layout_width="match_parent" 15 android:layout_height="wrap_content" 16 android:hint="请输入姓名"/> 17 18 <EditText android:id="@+id/ed_age" 19 android:layout_width="match_parent" 20 android:layout_height="wrap_content" 21 android:hint="请输入年龄" 22 android:layout_below="@+id/ed_name"/> 23 24 <EditText android:id="@+id/ed_sex" 25 android:layout_width="match_parent" 26 android:layout_height="wrap_content" 27 android:hint="请输入性别" 28 android:layout_below="@+id/ed_age"/> 29 30 <Button android:id="@+id/but_queding" 31 android:layout_width="match_parent" 32 android:layout_height="wrap_content" 33 android:hint="修改用户" 34 android:layout_below="@+id/ed_sex"/> 35 36 <Button android:id="@+id/but_tianjia" 37 android:layout_width="match_parent" 38 android:layout_height="wrap_content" 39 android:hint="添加用户" 40 android:layout_below="@+id/ed_sex"/> 41 42 43 </RelativeLayout >
这里要说一下，添加数据和修改数据用的是一个布局，在JAva文件中通过判断来确定是修改还是添加，
下面贴出JAVA代码
1 package wuxianedu.com.sqllistview; 2 3 import android.content.ContentValues; 4 import android.content.Intent; 5 import android.database.sqlite.SQLiteDatabase; 6 import android.support.v7.app.AppCompatActivity; 7 import android.os.Bundle; 8 import android.view.Menu; 9 import android.view.MenuItem; 10 import android.widget.ListView; 11 12 import java.util.List; 13 14 import wuxianedu.com.sqllistview.DB.DBauxiliary; 15 16 public class MainActivity extends AppCompatActivity { 17 18 private MainAdapter mainAdapter;//构建数据源 19 private List list;//接收数据的LIST 20 private DBauxiliary db;//数据库操作类的实例 21 22 @Override 23 protected void onCreate(Bundle savedInstanceState) { 24 super.onCreate(savedInstanceState); 25 setContentView(R.layout.activity_main); 26 ListView listView = (ListView) findViewById(R.id.lv_liebiao); 27 db = DBauxiliary.getInstance(this); 28 list= db.select(); 29 //构建数据源 30 mainAdapter = new MainAdapter(this,list); 31 //添加数据 32 listView.setAdapter(mainAdapter); 33 } 34 //Activity创建或者从被覆盖、后台重新回到前台时被调用 35 @Override 36 protected void onResume() { 37 super.onResume(); 38 //重新获取list数据 39 list = db.select(); 40 //给list赋值 更新 41 mainAdapter.setList(list); 42 } 43 44 @Override //菜单的点击事件 45 public boolean onCreateOptionsMenu(Menu menu) { 46 getMenuInflater().inflate(R.menu.menu,menu); 47 menu.findItem(R.id.add).setOnMenuItemClickListener(new MenuItem.OnMenuItemClickListener() { 48 @Override 49 public boolean onMenuItemClick(MenuItem item) { 50 //点击添加跳转 51 Intent intent=new Intent(MainActivity.this,UpdateActivity.class); 52 startActivityForResult(intent,5); 53 return false; 54 } 55 }); 56 return super.onCreateOptionsMenu(menu); 57 58 } 59 }
MainAdapter.java
此文件用来填充Adapter数据
1 package wuxianedu.com.sqllistview; 2 3 import android.content.Context; 4 import android.content.DialogInterface; 5 import android.content.Intent; 6 import android.support.v7.app.AlertDialog; 7 import android.view.LayoutInflater; 8 import android.view.View; 9 import android.view.ViewGroup; 10 import android.widget.BaseAdapter; 11 import android.widget.Button; 12 import android.widget.TextView; 13 import android.widget.Toast; 14 15 import java.util.List; 16 17 import wuxianedu.com.sqllistview.DB.DBauxiliary; 18 19 /** 20 * Created by Administrator on 2016/9/20. 21 */ 22 public class MainAdapter extends BaseAdapter { 23 private Context context; 24 private List<JavaBean> list;//接收数据的LIST 25 private DBauxiliary db;//数据库操作类的实例 26 //适配器 27 public MainAdapter(Context context,List<JavaBean> list){ 28 this.context = context; 29 this.list = list; 30 } 31 //更新集合用 32 public void setList(List<JavaBean> list) { 33 this.list = list; 34 notifyDataSetChanged(); 35 } 36 37 @Override 38 public int getCount() { 39 return list.size(); 40 } 41 42 @Override 43 public Object getItem(int position) { 44 return list.get(position); 45 } 46 47 @Override 48 public long getItemId(int position) { 49 return position; 50 } 51 52 @Override 53 public View getView(final int position, View convertView, ViewGroup parent) { 54 final HUi hui; 55 if(convertView == null){ 56 hui = new HUi(); 57 final int wo ; 58 wo = position; 59 db = DBauxiliary.getInstance(context); 60 convertView = LayoutInflater.from(context).inflate(R.layout.item_lie, null); 61 hui.name = (TextView) convertView.findViewById(R.id.tv_name); 62 hui.age = (TextView) convertView.findViewById(R.id.tv_age); 63 hui.sex = (TextView) convertView.findViewById(R.id.tv_sex); 64 hui.update = (Button) convertView.findViewById(R.id.but_name); 65 hui.delete = (Button) convertView.findViewById(R.id.but_delete); 66 67 // 68 //修改按钮 69 hui.update.setOnClickListener(new View.OnClickListener() { 70 @Override 71 public void onClick(View v) { 72 Intent intent = new Intent(context,UpdateActivity.class); 73 int on = (int) hui.update.getTag(); 74 JavaBean javabean = list.get(on); 75 intent.putExtra("name",javabean); 76 context.startActivity(intent); 77 78 } 79 }); 80 convertView.setTag(hui); 81 }else{ 82 hui = (HUi) convertView.getTag(); 83 } 84 85 final JavaBean java = list.get(position); 86 hui.update.setTag(position); 87 hui.name.setText(java.getName()); 88 hui.age.setText(String.valueOf(java.getAge())); 89 hui.sex.setText(java.getSex()); 90 final String naaa = java.getName(); 91 //构建删除对话框 92 hui.delete.setOnClickListener(new View.OnClickListener() { 93 @Override 94 public void onClick(View v) { 95 AlertDialog.Builder builder = new AlertDialog.Builder(context); 96 builder.setMessage("确定删除吗？"); 97 builder.setPositiveButton("取消",null); 98 builder.setNegativeButton("确定", new DialogInterface.OnClickListener() { 99 @Override 100 public void onClick(DialogInterface dialog, int which) { 101 db.delete(naaa); 102 list = db.select(); 103 setList(list); 104 notifyDataSetChanged(); 105 Toast.makeText(context,"删除成功",Toast.LENGTH_SHORT).show(); 106 } 107 }).show(); 108 109 } 110 }); 111 return convertView; 112 } 113 114 class HUi { 115 TextView name,age,sex; 116 Button update,delete; 117 } 118 }
UpdateActivity.java
用于添加和修改数据
1 package wuxianedu.com.sqllistview; 2 3 import android.content.ContentValues; 4 import android.content.Intent; 5 import android.support.v7.app.AppCompatActivity; 6 import android.os.Bundle; 7 import android.view.View; 8 import android.widget.Button; 9 import android.widget.EditText; 10 import android.widget.Toast; 11 12 import wuxianedu.com.sqllistview.DB.DBauxiliary; 13 14 public class UpdateActivity extends AppCompatActivity implements View.OnClickListener { 15 16 private DBauxiliary db; 17 private EditText ed_name,ed_sex,ed_age; 18 private JavaBean com; 19 private Button xiugai,shanchu; 20 21 @Override 22 protected void onCreate(Bundle savedInstanceState) { 23 super.onCreate(savedInstanceState); 24 setContentView(R.layout.activity_update); 25 ed_name= (EditText) findViewById(R.id.ed_name); 26 ed_age = (EditText) findViewById(R.id.ed_age); 27 ed_sex = (EditText) findViewById(R.id.ed_sex); 28 xiugai = (Button) findViewById(R.id.but_tianjia); 29 shanchu = (Button) findViewById(R.id.but_queding); 30 Intent on = getIntent(); 31 com = (JavaBean) on.getSerializableExtra("name"); 32 if(com == null){ 33 shanchu.setVisibility(View.GONE); 34 }else{ 35 xiugai.setVisibility(View.GONE); 36 ed_name.setText(com.getName()+""); 37 ed_age.setText(String.valueOf(com.getAge())+""); 38 ed_sex.setText(com.getSex()+""); 39 } 40 db = DBauxiliary.getInstance(UpdateActivity.this); 41 /* ed_name.setText(com.getName()+""); 42 ed_age.setText(String.valueOf(com.getAge())+""); 43 ed_sex.setText(com.getSex()+"");*/ 44 xiugai.setOnClickListener(this); 45 shanchu.setOnClickListener(this); 46 47 } 48 private void SqlInsert(){ 49 ContentValues contentValues = new ContentValues(); 50 contentValues.put("name",ed_name.getText().toString()); 51 contentValues.put("age",ed_age.getText().toString()); 52 contentValues.put("sex",ed_sex.getText().toString()); 53 db.insert(contentValues); 54 Toast.makeText(UpdateActivity.this,"添加成功",Toast.LENGTH_SHORT).show(); 55 } 56 //删除数据 57 private void SqlUpdate(){ 58 ContentValues contentValues = new ContentValues(); 59 contentValues.put("name",ed_name.getText().toString()); 60 contentValues.put("age",ed_age.getText().toString()); 61 contentValues.put("sex",ed_sex.getText().toString()); 62 db.update(contentValues,com.getName()); 63 Toast.makeText(UpdateActivity.this,"修改成功",Toast.LENGTH_SHORT).show(); 64 } 65 //判断 66 protected void onActivityResult(int requestCode, int resultCode, Intent data) { 67 if(requestCode != 5){ 68 69 } 70 } 71 72 @Override 73 public void onClick(View v) { 74 switch (v.getId()){ 75 case R.id.but_queding: 76 SqlUpdate(); 77 break; 78 case R.id.but_tianjia: 79 SqlInsert(); 80 break; 81 } 82 } 83 }
到这里所有功能就都写完了，我都写上注释了，如果有不明白的也可以留言，也可以加我Q,1171628833，本人刚安卓，小白一个，有同是小白的可以一起交流，共同成长，其他有一个Menu菜单，我没有写，因为不太明白，
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