安卓基础学习5

 1 读取系统联系人

   raw_contact 唯一标示 _id
   data  联系人的数据  
   mimetypes  数据的类型  

 2 向系统插入联系人信息

package com.itcast.contacts;import android.app.Activity;import android.content.ContentResolver;import android.content.ContentUris;import android.content.ContentValues;import android.database.Cursor;import android.net.Uri;import android.os.Bundle;import android.util.Log;import android.view.Menu;import android.view.View;public class MainActivity extends Activity {private static final String TAG = "MainActivity";private ContentResolver resolver;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);resolver = getContentResolver();}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.activity_main, menu);return true;}public void readContact(View v) {// matcher.addURI(ContactsContract.AUTHORITY, "raw_contacts",// RAW_CONTACTS);// matcher.addURI(ContactsContract.AUTHORITY, "raw_contacts/#",// RAW_CONTACTS_ID);// matcher.addURI(ContactsContract.AUTHORITY, "raw_contacts/#/data",// RAW_CONTACTS_DATA);Uri uri = Uri.parse("content://com.android.contacts/raw_contacts");Cursor c = resolver.query(uri, new String[] { "_id" }, null, null, null);while (c.moveToNext()) {String _id = c.getString(0);uri = Uri.parse("content://com.android.contacts/raw_contacts/" + _id + "/data");Cursor cursor = resolver.query(uri, new String[] { "data1","mimetype" }, null, null, null);String name = null;String phone = null;String email = null;while (cursor.moveToNext()) {String data = cursor.getString(0);String mimetype = cursor.getString(1);if ("vnd.android.cursor.item/name".equals(mimetype)) {name = data;} else if ("vnd.android.cursor.item/phone_v2".equals(mimetype)) {phone = data;} else if ("vnd.android.cursor.item/email_v2".equals(mimetype)) {email = data;}}Log.i(TAG, "name:" + name + ",phone:" + phone + ",email:" + email);}}public void addContact(View v) {Uri uri = Uri.parse("content://com.android.contacts/raw_contacts");ContentValues values = new ContentValues();Uri retUri = resolver.insert(uri, values );//获取返回的idlong raw_contact_id = ContentUris.parseId(retUri);uri = uri.parse("content://com.android.contacts/data");values.clear();values.put("raw_contact_id", raw_contact_id);values.put("data1", "小国国");values.put("mimetype","vnd.android.cursor.item/name");resolver.insert(uri, values);values.clear();values.put("raw_contact_id", raw_contact_id);values.put("data1", "123456");values.put("mimetype","vnd.android.cursor.item/phone_v2");resolver.insert(uri, values);values.clear();values.put("raw_contact_id", raw_contact_id);values.put("data1", "[e-mail]");values.put("mimetype","vnd.android.cursor.item/email_v2");resolver.insert(uri, values);}}

 3 内容观察者
 4 内容观察者的原理

 5 通过内容观察者检测短信的到来

原理：1.

1.内容观察者注册监听

package com.itcast.provider.query;import android.app.Activity;import android.content.ContentResolver;import android.database.ContentObserver;import android.net.Uri;import android.os.Bundle;import android.os.Handler;import android.util.Log;import android.view.Menu;import android.view.View;public class MainActivity extends Activity {private Uri uri;private static final String TAG = "MainActivity";private ContentResolver resolver;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);Log.i(TAG, "注册内容监听");resolver = getContentResolver();uri = Uri.parse("content://itcast");resolver.registerContentObserver(uri, true, new MyContentObserver(new Handler()));}private class MyContentObserver extends ContentObserver{public MyContentObserver(Handler handler) {super(handler);}@Overridepublic void onChange(boolean selfChange) {// TODO Auto-generated method stubsuper.onChange(selfChange);resolver.query(uri, new String[]{"*"}, null, null, null);Log.i(TAG, "读取到变化。。。");}}}

2.内容提供者中数据发生变化的时候调用getContext().getContentResolver().notifyChange(uri, null);通知注册了本uri的内容观察者

package com.itcast.providers;import android.content.ContentProvider;import android.content.ContentValues;import android.content.UriMatcher;import android.database.Cursor;import android.net.Uri;import android.util.Log;public class MyContentProvider extends ContentProvider {private static UriMatcher matcher = new UriMatcher(UriMatcher.NO_MATCH);static{matcher.addURI("itcast", null, 1);}private static final String TAG = "MainActivity";@Overridepublic boolean onCreate() {Log.i(TAG, "内容提供者初始化");return false;}@Overridepublic Cursor query(Uri uri, String[] projection, String selection,String[] selectionArgs, String sortOrder) {// TODO Auto-generated method stubreturn null;}@Overridepublic String getType(Uri uri) {// TODO Auto-generated method stubreturn null;}@Overridepublic Uri insert(Uri uri, ContentValues values) {getContext().getContentResolver().notifyChange(uri, null);return null;}@Overridepublic int delete(Uri uri, String selection, String[] selectionArgs) {getContext().getContentResolver().notifyChange(uri, null);return 0;}@Overridepublic int update(Uri uri, ContentValues values, String selection,String[] selectionArgs) {getContext().getContentResolver().notifyChange(uri, null);return 0;}}

3.测试数据库变化

package com.itcast.provider.add;import android.net.Uri;import android.os.Bundle;import android.app.Activity;import android.content.ContentResolver;import android.content.ContentValues;import android.util.Log;import android.view.Menu;public class MainActivity extends Activity {private static final String TAG = "MainActivity";@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);ContentResolver resolver = getContentResolver();ContentValues values = new ContentValues();Log.i(TAG, "即将插入数据");resolver.insert(Uri.parse("content://itcast"), values );}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.activity_main, menu);return true;}}

 6 网络图片查看器

package com.itcast.netimageview;import java.io.File;import java.io.FileOutputStream;import java.net.HttpURLConnection;import java.net.URL;import android.app.Activity;import android.graphics.Bitmap;import android.graphics.Bitmap.CompressFormat;import android.graphics.BitmapFactory;import android.net.Uri;import android.os.Bundle;import android.os.Environment;import android.os.Handler;import android.os.Message;import android.util.Log;import android.view.Menu;import android.view.View;import android.widget.ImageView;import android.widget.Toast;public class MainActivity extends Activity {protected static final int UPDATE = 0;protected static final int ERROR = 1;protected static final String TAG = "MainActivity";private Handler handler = new Handler() {public void handleMessage(Message msg) {switch (msg.what) {case UPDATE:Uri uri = (Uri) msg.obj;iv.setImageURI(uri);break;case ERROR:Toast.makeText(getApplicationContext(), "获取失败", 1).show();break;default:break;}};};private ImageView iv;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);iv = (ImageView) findViewById(R.id.iv);}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.activity_main, menu);return true;}public void download(View v) {new Thread() {public void run() {try {URL url = new URL("http://10.0.2.2/web/a.jpg");HttpURLConnection conn = (HttpURLConnection) url.openConnection();conn.setConnectTimeout(5000);conn.setRequestMethod("GET");if (conn.getResponseCode() != 200) {throw new RuntimeException("请求url失败");}File file = new File(Environment.getExternalStorageDirectory(), getFileName(url.getPath()));if (file.exists()) {Uri uri = Uri.fromFile(file);Message msg = Message.obtain();msg.what = UPDATE;msg.obj = uri;handler.sendMessage(msg);Log.i(TAG, "从缓存加载");}else {Bitmap bitmap = BitmapFactory.decodeStream(conn.getInputStream());//缓存bitmap.compress(CompressFormat.JPEG, 100, new FileOutputStream(file));Uri uri = Uri.fromFile(file);Message msg = Message.obtain();msg.what = UPDATE;msg.obj = uri;handler.sendMessage(msg);Log.i(TAG, "从网络加载");conn = null;url =null;}} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();Message msg = Message.obtain();msg.what = ERROR;handler.sendMessage(msg);}}}.start();}private String getFileName(String path) {return path.substring(path.lastIndexOf("/")+1);}}

 7 anr产生的原因如何避免anr异常
 8 android下的消息机制(强调在4.0的是不允许在主线程访问网络)

 9 android下消息机制的实现（查看Looper的源代码）

 10 图片查看器的异步处理

 11 开源项目smartimageview  碉堡了

protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);siv = (SmartImageView) findViewById(R.id.siv);siv.setImageUrl("http://10.0.2.2/web/a.jpg");}

 12 html源码查看器

package com.itcast.nettextview;import java.io.ByteArrayOutputStream;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.URL;import android.app.Activity;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.view.Menu;import android.view.View;import android.widget.TextView;import android.widget.Toast;public class MainActivity extends Activity {protected static final int UPDATE = 0;protected static final int ERROR = 1;private Handler handler = new Handler() {public void handleMessage(Message msg) {switch (msg.what) {case UPDATE:String content = (String) msg.obj;tv.setText(content);break;case ERROR:Toast.makeText(getApplicationContext(), "获取失败", 1).show();break;default:break;}};};private TextView tv;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);tv = (TextView) findViewById(R.id.tv);}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.activity_main, menu);return true;}public void download(View v) {new Thread() {public void run() {try {URL url = new URL("http://10.0.2.2/web/index.jsp");HttpURLConnection conn = (HttpURLConnection) url.openConnection();conn.setConnectTimeout(5000);conn.setRequestMethod("GET");if (conn.getResponseCode() != 200) {throw new RuntimeException("请求url失败");}InputStream in = conn.getInputStream();ByteArrayOutputStream bos = new ByteArrayOutputStream();byte [] buffer = new byte[1024];int len = 0;while((len=in.read(buffer))!=-1){bos.write(buffer,0,len);}String content = bos.toString();Message msg = Message.obtain();msg.what = UPDATE;msg.obj = content;handler.sendMessage(msg);conn = null;url =null;} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();Message msg = Message.obtain();msg.what = ERROR;handler.sendMessage(msg);}};}.start();}}

 13 采用get的方式提交数据到服务器&中文乱码问题的处理

URLEncoder.encode()

 14 post方式提交数据到服务器&中文乱码问题的处理

 15 HttpClient  下载文件

package com.itcast.httpdownload;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import org.apache.http.HttpResponse;import org.apache.http.client.ClientProtocolException;import org.apache.http.client.HttpClient;import org.apache.http.client.methods.HttpGet;import org.apache.http.impl.client.DefaultHttpClient;import android.os.Bundle;import android.os.Environment;import android.app.Activity;import android.view.Menu;import android.view.View;public class MainActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.activity_main, menu);return true;}public void download(View v) {new Thread() {public void run() {try {HttpClient client = new DefaultHttpClient();HttpGet request = new HttpGet("http://10.0.2.2/web/a.jpg");HttpResponse response = client.execute(request);if (response.getStatusLine().getStatusCode()==200) {File file = new File(Environment.getExternalStorageDirectory(), "hehe.jpg");FileOutputStream fos = new FileOutputStream(file);InputStream is = response.getEntity().getContent();byte []buffer = new byte[1024];int len = 0;while ((len = is.read(buffer))!=-1) {fos.write(buffer, 0, len);}fos.close();is.close();}} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}};}.start();}}

16解析网络json

package com.itcast.nettextview;import java.io.ByteArrayOutputStream;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.URL;import java.util.ArrayList;import java.util.List;import org.json.JSONArray;import org.json.JSONObject;import org.xmlpull.v1.XmlPullParser;import android.R.integer;import android.app.Activity;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.util.Log;import android.util.Xml;import android.view.Menu;import android.view.View;import android.widget.TextView;import android.widget.Toast;import com.itcast.nettextview.domain.Person;public class MainActivity extends Activity {protected static final int UPDATE = 0;protected static final int ERROR = 1;protected static final String TAG = "MainActivity";private Handler handler = new Handler() {public void handleMessage(Message msg) {switch (msg.what) {case UPDATE:break;case ERROR:Toast.makeText(getApplicationContext(), "获取失败", 1).show();break;default:break;}};};private TextView tv;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);tv = (TextView) findViewById(R.id.tv);}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.activity_main, menu);return true;}public void download(View v) {new Thread() {public void run() {try {URL url = new URL("http://10.0.2.2/web/JsonServlet");HttpURLConnection conn = (HttpURLConnection) url.openConnection();conn.setConnectTimeout(5000);conn.setRequestMethod("GET");if (conn.getResponseCode() != 200) {throw new RuntimeException("请求url失败");}InputStream in = conn.getInputStream();ByteArrayOutputStream bos = new ByteArrayOutputStream();byte [] buffer = new byte[1024];int len = 0;while((len=in.read(buffer))!=-1){bos.write(buffer,0,len);}String json = bos.toString();//[{id:1,name:"张三",age:18},{id:1,name:"张三",age:18}]JSONArray jsonArray = new JSONArray(json);for (int i = 0; i < jsonArray.length(); i++) {JSONObject jsonObject = (JSONObject) jsonArray.get(i);Person person = new Person();person._id = Integer.parseInt(jsonObject.getString("id"));person.name = jsonObject.getString("name");person.age = Integer.parseInt(jsonObject.getString("age"));Log.i(TAG, person.toString());}Message msg = Message.obtain();msg.what = UPDATE;handler.sendMessage(msg);conn = null;url = null;} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();Message msg = Message.obtain();msg.what = ERROR;handler.sendMessage(msg);}};}.start();}}

17.解析网络xml

package com.itcast.nettextview;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.URL;import java.util.ArrayList;import java.util.List;import org.xmlpull.v1.XmlPullParser;import android.R.integer;import android.app.Activity;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.util.Log;import android.util.Xml;import android.view.Menu;import android.view.View;import android.widget.TextView;import android.widget.Toast;import com.itcast.nettextview.domain.Person;public class MainActivity extends Activity {protected static final int UPDATE = 0;protected static final int ERROR = 1;protected static final String TAG = "MainActivity";private Handler handler = new Handler() {public void handleMessage(Message msg) {switch (msg.what) {case UPDATE:break;case ERROR:Toast.makeText(getApplicationContext(), "获取失败", 1).show();break;default:break;}};};private TextView tv;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);tv = (TextView) findViewById(R.id.tv);}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.activity_main, menu);return true;}public void download(View v) {new Thread() {public void run() {try {URL url = new URL("http://10.0.2.2/web/persons.xml");HttpURLConnection conn = (HttpURLConnection) url.openConnection();conn.setConnectTimeout(5000);conn.setRequestMethod("GET");if (conn.getResponseCode() != 200) {throw new RuntimeException("请求url失败");}InputStream in = conn.getInputStream();XmlPullParser parser = Xml.newPullParser();parser.setInput(conn.getInputStream(), "UTF-8");int eventType = parser.getEventType();List<Person> ps = null;Person p =null;while (eventType != XmlPullParser.END_DOCUMENT) {switch (eventType) {case XmlPullParser.START_TAG:if (parser.getName().equals("persons")) {ps = new ArrayList<Person>();}else if (parser.getName().equals("person")) {p = new Person();p._id = Integer.parseInt(parser.getAttributeValue(0));} else if (parser.getName().equals("name")) {p.name = parser.nextText();} else if (parser.getName().equals("age")) {p.age = Integer.parseInt(parser.nextText());} break;case XmlPullParser.END_TAG:if (parser.getName().equals("person")) {ps.add(p);Log.i(TAG, p.toString());p=null;} break;default:break;}eventType = parser.next();}Message msg = Message.obtain();msg.what = UPDATE;handler.sendMessage(msg);conn = null;url = null;} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();Message msg = Message.obtain();msg.what = ERROR;handler.sendMessage(msg);}};}.start();}}