(一)首先就是数据的查询功能了,直接上代码吧:
具体布局
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:orientation="vertical" > 6 7 <LinearLayout 8 android:layout_width="match_parent" 9 android:layout_height="wrap_content" 10 android:layout_gravity="top" 11 android:layout_weight="1" > 12 13 <TextView 14 android:layout_width="match_parent" 15 android:layout_height="60dp" 16 android:layout_marginTop="0dp" 17 android:gravity="center" 18 android:text="记账查询功能" 19 android:textColor="#77ff44" 20 android:textSize="40sp" /> 21 </LinearLayout> 22 23 <ListView 24 android:id="@+id/q_lv" 25 android:layout_width="match_parent" 26 android:layout_height="wrap_content" 27 android:layout_gravity="center_vertical" 28 android:layout_marginTop="50dp" 29 android:layout_weight="1" 30 android:minHeight="20dp" > 31 </ListView> 32 33 <LinearLayout 34 android:layout_width="match_parent" 35 android:layout_height="wrap_content" > 36 37 <EditText 38 android:id="@+id/et_qThings" 39 android:layout_width="match_parent" 40 android:layout_height="50dp" 41 android:layout_marginBottom="0dp" 42 android:hint="输入事件用来查询具体信息" /> 43 </LinearLayout> 44 45 <LinearLayout 46 android:layout_width="match_parent" 47 android:layout_height="wrap_content" 48 android:layout_weight="1" > 49 50 <Button 51 android:layout_width="wrap_content" 52 android:layout_height="wrap_content" 53 android:layout_weight="1" 54 android:onClick="query" 55 android:text="点我查询" /> 56 </LinearLayout> 57 58 </LinearLayout>
实现功能(我只实现了用事件名来模糊查找,当然要添加其他的查找标签可以自行添加,里面调用了之前博客提到的item布局,如有需要可以自行查看):
1 package com.example.hhah; 2 3 import java.util.ArrayList; 4 import java.util.List; 5 6 import android.app.Activity; 7 import android.content.res.Resources.NotFoundException; 8 import android.database.Cursor; 9 import android.database.DatabaseUtils; 10 import android.database.sqlite.SQLiteDatabase; 11 import android.os.Bundle; 12 import android.view.View; 13 import android.view.animation.DecelerateInterpolator; 14 import android.widget.EditText; 15 import android.widget.ListView; 16 import android.widget.Toast; 17 18 public class query extends Activity { 19 private ListView lv; 20 private EditText et_things; 21 private ArrayList<Bean> arrayList; 22 private MyOpenHelper myOpenHelper; 23 private SQLiteDatabase db; 24 25 @Override 26 protected void onCreate(Bundle savedInstanceState) { 27 28 super.onCreate(savedInstanceState); 29 setContentView(R.layout.query); 30 lv = (ListView) findViewById(R.id.q_lv); 31 et_things = (EditText) findViewById(R.id.et_qThings); 32 arrayList = new ArrayList<Bean>(); 33 myOpenHelper = new MyOpenHelper(getApplicationContext()); 34 35 } 36 37 public void query(View view) { 38 String et_things1 = et_things.getText().toString().trim(); 39 db = myOpenHelper.getWritableDatabase(); 40 Cursor cursor = db.rawQuery("select * from biao01 where t_name like '%" + et_things1 + "%'", null); 41 if (cursor.getCount() == 0) { 42 Toast.makeText(getApplicationContext(), "找不到您输入的内容", 1).show(); 43 } else { 44 while (cursor.moveToNext()) { 45 int id = cursor.getInt(cursor.getColumnIndex("_id")); 46 String t_name = cursor.getString(cursor.getColumnIndex("t_name")); 47 String t_place = cursor.getString(cursor.getColumnIndex("t_place")); 48 String time = cursor.getString(cursor.getColumnIndex("time")); 49 Bean bean = new Bean(); 50 bean.setT_name(t_name); 51 bean.setT_place(t_place); 52 bean.setTime(time); 53 System.out.println(t_name); 54 arrayList.add(bean); 55 } 56 MyAdapter myAdapter = new MyAdapter(getApplicationContext(), arrayList, R.layout.item); 57 lv.setAdapter(myAdapter); 58 } 59 } 60 }
(二)实现数据的实时更新(我没有用notifyDataSetChanged()方法,不过这种方法我也尝试了,但是无效,查找解决方法,他们说是list代表存储内存位置的差异导致的,但是我尝试自己修改了还是没有用)
我使用的是调用 onrestart()方法,在这个方法里面嵌套oncreate方法,这样也能实现数据的实时更新,核心代码如下:
1 public void query(View view) { 2 Intent intent =new Intent (); 3 intent.setClass(this, query.class); 4 startActivity(intent); 5 6 } 7 @Override 8 protected void onRestart() { 9 this.onCreate(new Bundle()); 10 System.out.println("我被调用了"); 11 //myAdapter.notifyDataSetChanged(); 12 super.onRestart(); 13 }
(三)因为增删改查已经实现,之后会对界面进行优化包装
(四)稳定心态,厚积薄发