Android tips3

1 intent中调用电话本
     Intent intent = new Intent();
        // 设置Intent Action属性
        intent.setAction(Intent.ACTION_GET_CONTENT);
        // 设置Intent Type 属性
        intent.setType("vnd.android.cursor.item/phone");
        // 启动Activity
        startActivity(intent);


2 Intent回到home界面
   // 实例化Intent
        Intent i = new Intent();
        // 添加Action属性
        i.setAction(Intent.ACTION_MAIN);
        // 添加Category属性
        i.addCategory(Intent.CATEGORY_HOME);
        // 启动Activity
        startActivity(i);
3 常见的intent的解析
    1) // 查看_id 为1的用户电话信息
      data = "content://contacts/people/1";
uri = Uri.parse(data);
intent.setAction(Intent.ACTION_VIEW);
intent.setData(uri);
startActivity(intent);

    2) 编辑_id 为1的用户电话信息
      data = "content://contacts/people/1";
uri = Uri.parse(data);
intent.setAction(Intent.ACTION_EDIT);
intent.setData(uri);
startActivity(intent);

     3) // 显示拨打电话界面
      data = "tel:[phone]";
uri = Uri.parse(data);
intent.setAction(Intent.ACTION_DIAL);
intent.setData(uri);
startActivity(intent);

      4) 直接打电话
       data = "tel:[phone]";
uri = Uri.parse(data);
intent.setAction(Intent.ACTION_CALL);
intent.setData(uri);

       5) // 访问浏览器
    data = "http://www.google.com";
uri = Uri.parse(data);
intent.setAction(Intent.ACTION_VIEW);
intent.setData(uri);

     6)  访问地图
     data = "geo:39.92,116.46";
uri = Uri.parse(data);
intent = new Intent(Intent.ACTION_VIEW,uri);
startActivity(intent);

4 ) preference
    例子保存临时短信
     比如在oncreate中：
        SharedPreferences pre = getSharedPreferences(TEMP_SMS, MODE_WORLD_READABLE);
        String content = pre.getString("sms_content", "");
        myEditText.setText(content);

    onstop比如接电话时：
   super.onStop();
    SharedPreferences.Editor editor = getSharedPreferences(TEMP_SMS, MODE_WORLD_WRITEABLE).edit();
    editor.putString("sms_content", myEditText.getText().toString());
    editor.commit();
  实际上是保存在/data/data/package/shared_prefs/下的XML文件

5)bitmap读网上一个URL的地址，然后
    String urlStr = "http://xxxxx/zs.jpg";
      try {
URL url = new URL(urlStr);
// 1. 直接使用URL获得输入流
//InputStream in = url.openStream();

// 2. 获得URLconnection
URLConnection conn = url.openConnection();
InputStream in = conn.getInputStream();

// 3. 如果是HTTP协议可以使用HttpURLConnection
//HttpURLConnection httpConn = (HttpsURLConnection)conn;
//in = httpConn.getInputStream();

Bitmap bm = BitmapFactory.decodeStream(in);

imageView.setImageBitmap(bm);

} catch (Exception e) {
e.printStackTrace();
}

6 android中HTTP URL方式访问服务端的工具类及使用
  
   public class HttpUtil {
// 基础URL
public static final String BASE_URL="http://10.0.2.2:8085/test/";
// 获得Get请求对象request
public static HttpGet getHttpGet(String url){
HttpGet request = new HttpGet(url);
return request;
}
// 获得Post请求对象request
public static HttpPost getHttpPost(String url){
HttpPost request = new HttpPost(url);
return request;
}
// 根据请求获得响应对象response
public static HttpResponse getHttpResponse(HttpGet request) throws ClientProtocolException,

IOException{
HttpResponse response = new DefaultHttpClient().execute(request);
return response;
}
// 根据请求获得响应对象response
public static HttpResponse getHttpResponse(HttpPost request) throws ClientProtocolException,

IOException{
HttpResponse response = new DefaultHttpClient().execute(request);
return response;
}

// 发送Post请求，获得响应查询结果
public static String queryStringForPost(String url){
// 根据url获得HttpPost对象
HttpPost request = HttpUtil.getHttpPost(url);
String result = null;
try {
// 获得响应对象
HttpResponse response = HttpUtil.getHttpResponse(request);
// 判断是否请求成功
if(response.getStatusLine().getStatusCode()==200){
// 获得响应
result = EntityUtils.toString(response.getEntity());
return result;
}
} catch (ClientProtocolException e) {
e.printStackTrace();
result = "网络异常！";
return result;
} catch (IOException e) {
e.printStackTrace();
result = "网络异常！";
return result;
}
        return null;
    }
// 获得响应查询结果
public static String queryStringForPost(HttpPost request){
String result = null;
try {
// 获得响应对象
HttpResponse response = HttpUtil.getHttpResponse(request);
// 判断是否请求成功
if(response.getStatusLine().getStatusCode()==200){
// 获得响应
result = EntityUtils.toString(response.getEntity());
return result;
}
} catch (ClientProtocolException e) {
e.printStackTrace();
result = "网络异常！";
return result;
} catch (IOException e) {
e.printStackTrace();
result = "网络异常！";
return result;
}
        return null;
    }
// 发送Get请求，获得响应查询结果
public static  String queryStringForGet(String url){
// 获得HttpGet对象
HttpGet request = HttpUtil.getHttpGet(url);
String result = null;
try {
// 获得响应对象
HttpResponse response = HttpUtil.getHttpResponse(request);
// 判断是否请求成功
if(response.getStatusLine().getStatusCode()==200){
// 获得响应
result = EntityUtils.toString(response.getEntity());
return result;
}
} catch (ClientProtocolException e) {
e.printStackTrace();
result = "网络异常！";
return result;
} catch (IOException e) {
e.printStackTrace();
result = "网络异常！";
return result;
}
        return null;
    }

   使用：String username = userEditText.getText().toString();
// 获得密码
String pwd = pwdEditText.getText().toString();
// 获得登录结果
String result=query(username,pwd);


// 根据用户名称密码查询
private String query(String account,String password){
// 查询参数
String queryString = "account="+account+"&password="+password;
// url
String url = HttpUtil.BASE_URL+"servlet/LoginServlet?"+queryString;
// 查询返回结果
return HttpUtil.queryStringForPost(url);
           
    将参数提交给服务端：使用apache http client:
     List<NameValuePair> params = new ArrayList<NameValuePair>();
// 添加请求参数
params.add(new BasicNameValuePair("orderTime", orderTime));
params.add(new BasicNameValuePair("userId", userId));
params.add(new BasicNameValuePair("tableId", tableId));
params.add(new BasicNameValuePair("personNum", personNum));
UrlEncodedFormEntity entity1=null;
try {
entity1 =  new UrlEncodedFormEntity(params,HTTP.UTF_8);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
// 请求服务器url
String url = HttpUtil.BASE_URL+"servlet/StartTableServlet";
// 获得请求对象HttpPost
HttpPost request = HttpUtil.getHttpPost(url);
// 设置查询参数
request.setEntity(entity1);
// 获得响应结果
String result= HttpUtil.queryStringForPost(request);