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;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
resolver = getContentResolver();
}
@Override
public 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id
long 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", "[email protected]");
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;
@Override
protected 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);
}
@Override
public void onChange(boolean selfChange) {
// TODO Auto-generated method stub
super.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";
@Override
public boolean onCreate() {
Log.i(TAG, "内容提供者初始化");
return false;
}
@Override
public Cursor query(Uri uri, String[] projection, String selection,
String[] selectionArgs, String sortOrder) {
// TODO Auto-generated method stub
return null;
}
@Override
public String getType(Uri uri) {
// TODO Auto-generated method stub
return null;
}
@Override
public Uri insert(Uri uri, ContentValues values) {
getContext().getContentResolver().notifyChange(uri, null);
return null;
}
@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
getContext().getContentResolver().notifyChange(uri, null);
return 0;
}
@Override
public 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";
@Override
protected 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 );
}
@Override
public 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;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
iv = (ImageView) findViewById(R.id.iv);
}
@Override
public 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 block
e.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）
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;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv = (TextView) findViewById(R.id.tv);
}
@Override
public 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 block
e.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 {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
@Override
public 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 block
e.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;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv = (TextView) findViewById(R.id.tv);
}
@Override
public 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 block
e.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;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv = (TextView) findViewById(R.id.tv);
}
@Override
public 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 block
e.printStackTrace();
Message msg = Message.obtain();
msg.what = ERROR;
handler.sendMessage(msg);
}
};
}.start();
}
}