Android-用两个activity实现少女心爆棚的便签（xutil框架实现）

首先上图看效果，由于不能上传视频，多图预警，支持增，删，改，查，搜索。由于篇幅有限，有些xml文件不能上传，想要整个工程可以进行下载，或者私信俺。如果不会xutil数据库操作，可以先进行学习

在这里只贴出，java代码
首先得添加框架依赖

   implementation 'com.facebook.stetho:stetho:1.5.1'implementation 'org.xutils:xutils:3.8.5'implementation 'com.scwang.smartrefresh:SmartRefreshLayout:1.1.2'  //1.0.5及以前版本的老用户升级需谨慎，API改动过大implementation 'com.scwang.smartrefresh:SmartRefreshHeader:1.1.2'  //没有使用特殊Header，可以不加这行

第一个activity.java代码

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.telephony.CellSignalStrength;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;import com.facebook.stetho.Stetho;
import com.scwang.smartrefresh.layout.api.RefreshLayout;
import com.scwang.smartrefresh.layout.listener.OnLoadMoreListener;
import com.scwang.smartrefresh.layout.listener.OnRefreshListener;import org.xutils.DbManager;
import org.xutils.db.Selector;
import org.xutils.ex.DbException;
import org.xutils.x;import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;public class MainActivity extends AppCompatActivity {static DbManager.DaoConfig daoConfig;//用来增加数据使用,表示idstatic int nums;//用来表示是新建还是修改static boolean flag=true;//切换布局static boolean flagRecycle=true;static MyAdapter myAdapter;static List<Messages> users;static List<Messages> userstemp;static RecyclerView recyclerView;Messages messages;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);Stetho.initializeWithDefaults(this);x.Ext.init(getApplication());x.Ext.setDebug(BuildConfig.DEBUG);// 是否输出debug日志, 开启debug会影响性能.x.view().inject(this);//没有用到view注解可以先不用final EditText editText=findViewById(R.id.editText2);//数据库创建daoConfig= new DbManager.DaoConfig().setDbName("messages.db")// 不设置dbDir时, 默认存储在app的私有目录.// .setDbDir(new File("/sdcard")) // "sdcard"的写法并非最佳实践, 这里为了简单, 先这样写了..setDbVersion(1).setDbOpenListener(new DbManager.DbOpenListener() {@Overridepublic void onDbOpened(DbManager db) {// 开启WAL, 对写入加速提升巨大db.getDatabase().enableWriteAheadLogging();}}).setDbUpgradeListener(new DbManager.DbUpgradeListener() {@Overridepublic void onUpgrade(DbManager db, int oldVersion, int newVersion) {// TODO: ...// db.addColumn(...);// db.dropTable(...);// ...// or// db.dropDb();}});
//查询所有的数据,并显示到recycleviewDbManager db = null;try {// 删除1db = x.getDb(daoConfig);users= new ArrayList<>();users= db.selector(Messages.class).orderBy("id", true).limit(1000).findAll();
// users= db.selector(User.class).orderBy("id", true).limit(1000).findAll();
// users= db.selector(User.class).findAll();nums=users.size();} catch (DbException e) {e.printStackTrace();return;}//            搜索Button button=findViewById(R.id.button6);button.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {EditText seachEdit=findViewById(R.id.editText);String seachContent=seachEdit.getText().toString();DbManager db = null;try {// 删除1db = x.getDb(daoConfig);List<Messages> newMessge = new ArrayList<>();String sql="select * from Messages where content like "+"'%"+seachContent+"%'";Cursor cursor= db.execQuery(sql);while (cursor.moveToNext()){Messages m=new Messages();String seachmess=cursor.getString(1);m.setContent(seachmess);String seachdate=cursor.getString(2);m.setDate(seachdate);int seachid=cursor.getInt(0);m.setId(seachid);newMessge.add(m);Log.i("hhhh", "onClick: sousuo"+m.getContent()+" "+m.getDate()+" "+seachContent);}cursor.close();
//                        newMessge=db.selector(Messages.class).orderBy("id", true).where("content","like","%"+seachContent+"%").findAll();users=newMessge;myAdapter.notifyDataSetChanged();seachEdit.setText("");// users= db.selector(User.class).orderBy("id", true).limit(1000).findAll();
// users= db.selector(User.class).findAll();} catch (DbException e) {e.printStackTrace();return;}}});//    跳转到编写页面Button button2 =findViewById(R.id.button2);button2.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {flag=false;Intent intent=new Intent(MainActivity.this,Main2Activity.class);startActivity(intent);Log.i("hhhhh", "onClick: ");}});myAdapter = new MyAdapter();recyclerView =findViewById(R.id.recyclerView);recyclerView.setAdapter(myAdapter);
//设置边距HashMap<String, Integer> stringIntegerHashMap = new HashMap<>();stringIntegerHashMap.put(RecyclerViewSpacesItemDecoration.TOP_DECORATION,30);//top间距stringIntegerHashMap.put(RecyclerViewSpacesItemDecoration.BOTTOM_DECORATION,50);//底部间距stringIntegerHashMap.put(RecyclerViewSpacesItemDecoration.LEFT_DECORATION,50);//左间距stringIntegerHashMap.put(RecyclerViewSpacesItemDecoration.RIGHT_DECORATION,50);//右间距recyclerView.addItemDecoration(new RecyclerViewSpacesItemDecoration(stringIntegerHashMap));recyclerView.setLayoutManager(new LinearLayoutManager(MainActivity.this));//            刷新RefreshLayout refreshLayout = findViewById(R.id.refreshLayout);refreshLayout.setOnRefreshListener(new OnRefreshListener() {@Overridepublic void onRefresh(RefreshLayout refreshlayout) {DbManager db = null;try {// 删除1db = x.getDb(daoConfig);users= new ArrayList<>();users= db.selector(Messages.class).orderBy("id", true).limit(1000).findAll();
// users= db.selector(User.class).orderBy("id", true).limit(1000).findAll();
// users= db.selector(User.class).findAll();nums=users.size();} catch (DbException e) {e.printStackTrace();return;}myAdapter.notifyDataSetChanged();refreshlayout.finishRefresh(2000/*,false*/);//传入false表示刷新失败}});refreshLayout.setOnLoadMoreListener(new OnLoadMoreListener() {@Overridepublic void onLoadMore(RefreshLayout refreshlayout) {myAdapter.notifyDataSetChanged();refreshlayout.finishLoadMore(2000/*,false*/);//传入false表示加载失败}});//            切换布局Button button4=findViewById(R.id.button4);button4.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (flagRecycle) {//如果为真，代表线性布局，设置为网格布局flagRecycle=false;recyclerView.setLayoutManager(new GridLayoutManager(MainActivity.this, 2, LinearLayoutManager.VERTICAL, false));}else {flagRecycle=true;recyclerView.setLayoutManager(new LinearLayoutManager(MainActivity.this));}}});}public  class MyViewHolder extends  RecyclerView.ViewHolder{//用来包装每个子项的布局信息public TextView textView1;public TextView textView2;public MyViewHolder(@NonNull View itemView) {super(itemView);textView1=itemView.findViewById(R.id.textView1);textView2=itemView.findViewById(R.id.textView2);}}public  class  MyAdapter extends RecyclerView.Adapter<MyViewHolder>{//用来配合recycleview进行加载子项以及填充子项的数据@Overridepublic MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, final int viewType) {final View view = LayoutInflater.from(MainActivity.this).inflate(R.layout.item1,parent,false);final MyViewHolder myViewHolder = new MyViewHolder(view);
//设置子项item监听myViewHolder.itemView.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {
//                        Messages user=new Messages();
                        user.setId();Intent intent=new Intent(MainActivity.this,Main2Activity.class);int id=myViewHolder.getAdapterPosition();//得到item的编号，位置
//                        String date=users.get(id).getDate();
//                        String content=users.get(id).getContent();
//跳转页面并实现传递参数intent.putExtra("mess",id);
//                        Log.i("hhhh", "onClick: "+id+"  "+users.get(id).getContent());startActivity(intent);}});//              设置监听
//                view.setOnClickListener(new View.OnClickListener() {
//                    @Override
//                    public void onClick(View v) {
                        Messages user=new Messages();
                        user.setId();
//                        Intent intent=new Intent(MainActivity.this,Main2Activity.class);
                        intent.putExtra("user",users.get())
//                        Log.i("hhhh", "onClick: "+view.getTag());
//                        startActivity(intent);
//                    }
//                });return myViewHolder;}@Overridepublic void onBindViewHolder(@NonNull MyViewHolder holder, int position) {//在这里进行子项的文本图片数据填充holder.textView1.setText(users.get(position).getContent());holder.textView2.setText(users.get(position).getDate());}@Overridepublic int getItemCount() {//返回子项的数目，即加载多少列表项return users.size();}}}

第二个activity.java代码

import androidx.appcompat.app.AppCompatActivity;import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.TextView;import com.facebook.stetho.Stetho;import org.xutils.DbManager;
import org.xutils.common.util.KeyValue;
import org.xutils.db.sqlite.WhereBuilder;
import org.xutils.ex.DbException;
import org.xutils.x;import java.text.SimpleDateFormat;
import java.util.Date;import static com.c201801020217.tangbo.MainActivity.daoConfig;
import static com.c201801020217.tangbo.MainActivity.flag;
import static com.c201801020217.tangbo.MainActivity.myAdapter;
import static com.c201801020217.tangbo.MainActivity.nums;
import static com.c201801020217.tangbo.MainActivity.users;public class Main2Activity extends AppCompatActivity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main2);Stetho.initializeWithDefaults(this);
//        返回final Button button=findViewById(R.id.button);
//        保存Button button2=findViewById(R.id.button7);
//        删除final Button button3=findViewById(R.id.button5);final TextView textViewDate=findViewById(R.id.textView);final TextView textContent=findViewById(R.id.editText2);SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");// HH:mm:ss
//获取当前时间Date date = new Date(System.currentTimeMillis());final String time= simpleDateFormat.format(date);textViewDate.setText(time);
//        Messages messages= (Messages) getIntent().getSerializableExtra("mess");final int id = getIntent().getIntExtra("mess", 0);final int itemid = users.get(id).getId();if(flag) {String dates = users.get(id).getDate();String content = users.get(id).getContent();textViewDate.setText(dates);textContent.setText(content);}//        保存button2.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {DbManager db = null;try {if (flag) {//如果为真，代表是点击item进来的，要用更新语句而不是插入语句
//条件更新String newcontent=textContent.getText().toString();db = x.getDb(daoConfig);db.update(Messages.class, WhereBuilder.b("id", "=", itemid),
// WhereBuilder.b("id", "=", 1).and("isAdmin", "=", true).,new KeyValue("content",newcontent), new KeyValue("date", time));users.get(id).setDate(time);users.get(id).setContent(newcontent);} else {db = x.getDb(daoConfig);Messages user = new Messages();//new 一个对象，相当于是表中的一行，相当于一条记录//相当于插入数据user.setId(nums + 1);nums++;user.setDate(time);user.setContent(textContent.getText().toString());db.save(user);//写入数据，保存到数据库flag=true;users.add(user);
//                       myAdapter.notifyDataSetChanged();}finish();} catch (DbException e) {e.printStackTrace();return;}}});
//        删除button3.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {//条件删除DbManager db = null;try {db = x.getDb(daoConfig);db.delete(Messages.class,WhereBuilder.b("id", "=", itemid));users.remove(id);} catch (DbException e) {e.printStackTrace();return;}finish();}});
//返回button.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {finish();}});}
}

数据库使用的java类

import org.xutils.db.annotation.Column;
import org.xutils.db.annotation.Table;import java.util.Date;@Table(name = "Messages")
public class Messages {@Column(name = "id",isId=true)private int id;@Column(name = "date")private String date;@Column(name = "content")private String content;public String getDate() {return date;}public void setDate(String date) {this.date = date;}public String getContent() {return content;}public void setContent(String content) {this.content = content;}public int getId() {return id;}public void setId(int id) {this.id = id;}
}