增删改查

  1 <?xml version="1.0" encoding="utf-8"?>
  2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  3     android:layout_width="match_parent"
  4     android:layout_height="match_parent"
  5     android:background="@drawable/huangdou"
  6     android:orientation="vertical"
  7    >
  8     <LinearLayout
  9         android:layout_width="match_parent"
 10         android:layout_height="wrap_content"
 11         android:orientation="horizontal"
 12         android:gravity="center">
 13         <ImageView
 14             android:layout_width="200dp"
 15             android:layout_height="200dp"
 16             android:background="@drawable/katong"
 17             />
 18     </LinearLayout>
 19   
 20     <LinearLayout
 21         android:layout_width="match_parent"
 22         android:layout_height="wrap_content"
 23         android:orientation="horizontal"
 24         android:layout_marginTop="10dp">
 25   
 26         <TextView
 27             android:layout_width="wrap_content"
 28             android:layout_height="wrap_content"
 29             android:text="姓名:"
 30             android:textSize="35dp"/>
 31         <EditText
 32             android:id="@+id/e_name"
 33             android:layout_width="match_parent"
 34             android:layout_height="wrap_content"
 35             android:hint="请输入姓名"
 36             android:textSize="35dp"
 37             />
 38   
 39     </LinearLayout>
 40     <LinearLayout
 41         android:layout_width="match_parent"
 42         android:layout_height="wrap_content"
 43         android:orientation="horizontal"
 44         android:layout_marginTop="10dp">
 45   
 46         <TextView
 47             android:layout_width="wrap_content"
 48             android:layout_height="wrap_content"
 49             android:text="电话:"
 50             android:textSize="35dp"/>
 51         <EditText
 52             android:id="@+id/e_phone"
 53             android:layout_width="match_parent"
 54             android:layout_height="wrap_content"
 55             android:hint="请输入手机号码"
 56             android:textSize="35dp"
 57             />
 58   
 59     </LinearLayout>
 60     <LinearLayout
 61         android:layout_width="match_parent"
 62         android:layout_height="wrap_content"
 63         android:orientation="horizontal"
 64         android:padding="10dp">
 65   
 66         <Button
 67             android:id="@+id/insert"
 68             android:layout_marginLeft="30dp"
 69             android:layout_width="wrap_content"
 70             android:layout_height="wrap_content"
 71             android:text="添加"
 72             android:textSize="34dp"
 73             android:drawableLeft="@drawable/bianse1"
 74             android:onClick="add"
 75             />
 76         <Button
 77             android:id="@+id/selet"
 78             android:layout_marginLeft="40dp"
 79             android:layout_width="wrap_content"
 80             android:layout_height="wrap_content"
 81             android:text="查询"
 82             android:textSize="34dp"
 83             android:drawableLeft="@drawable/bianse2"
 84             android:onClick="search"
 85             />
 86     </LinearLayout>
 87   
 88     <LinearLayout
 89         android:layout_width="match_parent"
 90         android:layout_height="wrap_content"
 91         android:orientation="horizontal"
 92         android:padding="10dp">
 93   
 94         <Button
 95             android:id="@+id/update"
 96             android:layout_marginLeft="30dp"
 97             android:layout_width="wrap_content"
 98             android:layout_height="wrap_content"
 99             android:text="修改"
100             android:textSize="34dp"
101             android:drawableLeft="@drawable/bianse3"
102             android:onClick="update"
103            />
104         <Button
105             android:id="@+id/drop"
106             android:layout_marginLeft="40dp"
107             android:layout_width="wrap_content"
108             android:layout_height="wrap_content"
109             android:text="删除"
110             android:textSize="34dp"
111             android:drawableLeft="@drawable/bianse4"
112             android:onClick="delete"
113            />
114     </LinearLayout>
115     <ListView
116         android:layout_width="fill_parent"
117         android:layout_height="fill_parent"
118         android:id="@+id/tv_show"
119         android:layout_marginTop="20dp"
120         android:textSize="20sp"/>
121   
122 </LinearLayout>
123 
124 
125 
126 
127 package com.example.zj;
128   
129 import androidx.appcompat.app.AppCompatActivity;
130   
131 import android.content.ContentValues;
132 import android.database.Cursor;
133 import android.database.sqlite.SQLiteDatabase;
134 import android.database.sqlite.SQLiteOpenHelper;
135 import android.os.Bundle;
136 import android.view.View;
137 import android.view.ViewGroup;
138 import android.widget.BaseAdapter;
139 import android.widget.Button;
140 import android.widget.EditText;
141 import android.widget.ListView;
142 import android.widget.TextView;
143 import android.widget.Toast;
144   
145 import java.util.ArrayList;
146 import java.util.List;
147   
148 public class HdouActivity extends AppCompatActivity {
149   
150     @Override
151     protected void onCreate(Bundle savedInstanceState) {
152         super.onCreate(savedInstanceState);
153         setContentView(R.layout.activity_hdou);
154     }
155   
156     public void add(View view) {
157         MyHelper myHelper = new MyHelper(this);
158         SQLiteDatabase db = myHelper.getWritableDatabase();
159         String name = ((EditText) findViewById(R.id.e_name)).getText()
160                 .toString();
161         int phone = Integer.parseInt(((EditText) findViewById(R.id.e_phone))
162                 .getText().toString());
163         db.execSQL("insert into stu (name,phone) values(?,?)", new Object[]{
164                 name, phone});
165         Toast.makeText(this, "ok", Toast.LENGTH_SHORT).show();
166     }
167   
168     public void delete(View view) {
169         MyHelper myHelper = new MyHelper(this);
170         SQLiteDatabase db = myHelper.getWritableDatabase();
171         db.execSQL("delete from stuinfo where name=?", new Object[]{2});
172         Toast.makeText(this, "删除成功", Toast.LENGTH_SHORT).show();
173     }
174   
175     public void update(View view) {
176         MyHelper myHelper = new MyHelper(this);
177         SQLiteDatabase db = myHelper.getWritableDatabase();
178         db.execSQL("update stu set name=? where name=?", new Object[]{
179                 "micky", 3});
180         Toast.makeText(this, "修改成功", Toast.LENGTH_SHORT).show();
181     }
182   
183     List<Student> list = new ArrayList<Student>();
184   
185     public void search(View view) {
186         System.out.println(list.size() + "在search里");
187         MyHelper myHelper = new MyHelper(this);
188         SQLiteDatabase db = myHelper.getWritableDatabase();
189         Cursor cursor = db.rawQuery("select * from stu", null);
190         if (cursor.getCount() != 0) {
191             //每循环一次，创建一个学生对象并添加到集合中
192             while (cursor.moveToNext()) {
193 //              s += cursor.getInt(0) + "   " + cursor.getString(1) + "   "
194 //                      + cursor.getInt(2) + "\n";
195                 Student s1 = new Student();
196                 s1.setName(cursor.getString(0));
197                 s1.setPhone(cursor.getInt(1));
198                 list.add(s1);
199             }
200         }
201         ListView lv = (ListView) findViewById(R.id.tv_show);
202         lv.setAdapter(new myadapter());
203     }
204   
205     private class myadapter extends BaseAdapter {
206         @Override
207         public int getCount() {
208             return list.size();
209         }
210   
211         @Override
212         public Object getItem(int i) {
213             return null;
214         }
215   
216         @Override
217         public long getItemId(int i) {
218             return 0;
219         }
220   
221         @Override
222         public View getView(int i, View view, ViewGroup viewGroup) {
223               View view1=View.inflate(HdouActivity.this,R.layout.list_item,null);
224             TextView tvname=(TextView)view.findViewById(R.id.tv_name);
225             TextView tvphone=(TextView) view.findViewById(R.id.tv_phone);
226   
227             System.out.println(list.get(i).getName());
228             tvname.setText(list.get(i).getName());
229             tvphone.setText(list.get(i).getName()+"");
230   
231             return view;
232         }
233     }
234 }
235 
236 package com.example.zj;
237   
238 import android.content.Context;
239 import android.database.sqlite.SQLiteDatabase;
240 import android.database.sqlite.SQLiteOpenHelper;
241   
242 import androidx.annotation.Nullable;
243   
244 public class MyHelper extends SQLiteOpenHelper {
245   
246   
247     public MyHelper(@Nullable Context context) {
248         super(context,"itcase.db", null, 1);
249     }
250   
251     @Override
252     public void onCreate(SQLiteDatabase db) {
253         db.execSQL("create table stu(name varchar(20) primary key,phone int(10))");
254     }
255   
256     @Override
257     public void onUpgrade(SQLiteDatabase db, int i, int i1) {
258   
259     }
260 }
261 
262 package com.example.zj;
263   
264 public class Student {
265     private String name;
266     private int phone;
267   
268   
269     public String getName(){
270         return name;
271     }
272   
273     public void setName(String name){
274         this.name=name;
275     }
276     public int getPhone(){
277         return phone;
278     }
279   
280     public void setPhone(int phone) {
281         this.phone = phone;
282     }
283 }