近期的一个实验用到东西挺多，特地总结一下。

要求功能：

       1、第一个页面加入歌曲名和歌手，跳到第二个页面列表显示全部记录。使用sqlite数据库

       2、对于第二个页面显示的信息能够进行删除和改动操作，并自己主动刷新

最后我做的效果：

 

长按列表项弹出单个管理的菜单，像微信好友对话管理一样。

删除时能够直接删除这一条并在列表中直接显示。更新时弹出对话框更新内容提交后在列表中又一次显示。

 

做此例遇到的困难：

1、菜单获取上下文

2、获取对话框中的内容

3、对话框button加入监听事件-----注意包不要导错：import android.content.DialogInterface.OnClickListener;

 

主要代码例如以下：

第一个页面：

package com.example.musiclist;import android.app.Activity;import android.content.Intent;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteException;import android.os.Bundle;import android.view.Menu;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;public class MainActivity extends Activity {	SQLiteDatabase db;	String music;	String singer;	Button add; 	@Override 	protected void onCreate(Bundle savedInstanceState) {		super.onCreate(savedInstanceState);		setContentView(R.layout.activity_main);		db = SQLiteDatabase.openOrCreateDatabase(this.getFilesDir().toString()+"/music.db3", null);		add = (Button)findViewById(R.id.add);		add.setOnClickListener(new OnClickListener(){			Cursor cursor = null;			public void onClick(View sourse){				music = ((EditText)findViewById(R.id.music)).getText().toString();				singer = ((EditText)findViewById(R.id.singer)).getText().toString();								try{					insertData(db,music,singer);				}catch(SQLiteException se){					//primary key autoincrement					db.execSQL("create table musiclist(_id integer primary key autoincrement," 							+"music varchar(30) ,"							+"singer varchar(30))");					insertData(db,music,singer);				}finally{					//cursor.close();					Intent intentSec = new Intent(MainActivity.this,SecondActivity.class);					startActivity(intentSec);				}			}		});	}	private void insertData(SQLiteDatabase db,String name,String weibo){		//运行插入语句		db.execSQL("insert into musiclist values(null,?,?

)",new String[]{music,singer}); } public void onDestroy(){ super.onDestroy(); if(db!=null&&db.isOpen()){ db.close(); } } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.main, menu); return true; } }

 

第二个页面:

package com.example.musiclist;import android.app.Activity;import android.app.AlertDialog;import android.content.DialogInterface;import android.content.DialogInterface.OnClickListener;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteException;import android.os.Bundle;import android.support.v4.widget.SimpleCursorAdapter;import android.view.ContextMenu;import android.view.ContextMenu.ContextMenuInfo;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.view.View.OnCreateContextMenuListener;import android.widget.AdapterView.AdapterContextMenuInfo;import android.widget.CursorAdapter;import android.widget.EditText;import android.widget.ListView;import android.widget.TableLayout;public class SecondActivity extends Activity {	SQLiteDatabase db;	ListView show;	@Override	protected void onCreate(Bundle savedInstanceState) {		super.onCreate(savedInstanceState);		setContentView(R.layout.activity_second);		show = (ListView)findViewById(R.id.show);		db = SQLiteDatabase.openOrCreateDatabase(this.getFilesDir().toString()+"/music.db3", null);		//显示列表		showlist();		// 加入长按点击弹出选择菜单		show.setOnCreateContextMenuListener(new OnCreateContextMenuListener() {			public void onCreateContextMenu(ContextMenu menu, View v,					ContextMenuInfo menuInfo) {				menu.setHeaderTitle("选择操作");				menu.add(0, 0, 0, "更新该条");				menu.add(0, 1, 0, "删除该条");			}		});	}	//给菜单项加入事件	@Override	public boolean onContextItemSelected(MenuItem item) {		AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();		//info.id得到listview中选择的条目绑定的id		String id = String.valueOf(info.id);		switch (item.getItemId()) {		case 0:			updateDialog(id);			return true;		case 1:			//System.out.println("删除"+info.id);			deleteData(db,id);			showlist();			return true;		default:			return super.onContextItemSelected(item);		}	}	//更新对话框	private void updateDialog(final String id){		final TableLayout updatemsg = (TableLayout)getLayoutInflater().inflate(R.layout.updatemsg, null);		new AlertDialog.Builder(this)		.setTitle("更新该条信息")		.setView(updatemsg)		.setPositiveButton("更新",new OnClickListener(){			@Override			public void onClick(DialogInterface dialog, int which) {				// TODO Auto-generated method stub				String musicN = ((EditText)updatemsg.findViewById(R.id.musicN)).getText().toString();				String singerN = ((EditText)updatemsg.findViewById(R.id.singerN)).getText().toString();				updateData(db,id,musicN,singerN);				showlist();			}		})		.setNegativeButton("取消", new OnClickListener(){			public void onClick(DialogInterface dialog,int which){			}		})		.create()		.show();	}	private void updateData(SQLiteDatabase db,String id,String musicN,String singerN){		db.execSQL("update musiclist set music='"+musicN+"',singer='"+singerN+"' where _id=?",new String[]{id});	}	//删除列表项	private void deleteData(SQLiteDatabase db,String id){		db.execSQL("delete from musiclist where _id=?",new String[]{id});	}	//显示列表项	private void showlist(){		Cursor cursor = null;		try{			cursor = db.rawQuery("select * from musiclist", null);			inflateList(cursor);		}catch(SQLiteException se){			db.execSQL("create table musiclist(_id integer primary key autoincrement," 					+"music varchar(30) ,"					+"singer varchar(30))");			//查询			cursor = db.rawQuery("select * from musiclist", null);			inflateList(cursor);		}finally{			//cursor.close();		}	}	private void inflateList(Cursor cursor){		//填充SimpleCursorAdapter		SimpleCursorAdapter adapter = new SimpleCursorAdapter(SecondActivity.this,R.layout.line,cursor,				new String[]{"_id","music","singer"},				new int[]{R.id.idS,R.id.musicS,R.id.singerS},				CursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);		show.setAdapter(adapter);	}	public void onDestroy(){		super.onDestroy();		if(db!=null&&db.isOpen()){			db.close();		}	}	@Override	public boolean onCreateOptionsMenu(Menu menu) {		// Inflate the menu; this adds items to the action bar if it is present.		getMenuInflater().inflate(R.menu.main, menu);		return true;	}}

 

 

列表 line.xml：

xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="horizontal"> <TextView android:id="@+id/idS" android:layout_width="wrap_content" android:layout_height="wrap_content" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text=" " /> <TextView android:id="@+id/musicS" android:layout_width="wrap_content" android:layout_height="wrap_content" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text=" " /> <TextView android:id="@+id/singerS" android:layout_width="wrap_content" android:layout_height="wrap_content" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text=" " /> </LinearLayout>

对话框：updatemsg.xml