Android基础篇 Uri

Posted 2021-09-01 彭老希

一、概述

通用资源标志符（Universal Resource Identifier, 简称"URI"）。Uri代表要操作的数据，android上可用的每种资源 (图像、视频片段、网页等) 都可以用Uri来表示。

Uri的通用格式为：scheme: scheme-specific-part #fragment

（一）形式

1. scheme://authority path ?query #fragment
2. scheme://host:port path ?query #fragment
3. scheme:scheme-specific-part #fragment

（二）作用 【scheme 替代为 XXXX ，例如第二种，http://host:port path?.. 】

第一种用于访问本地资源，这里的scheme为content或者file，如:

//访问通讯录中的某个联系人
//会利用系统通讯录app提供的provider去读取联系人信息
//从/data/data/com.android.providers.contacts/databases中的数据库表来访问
 
content://contacts/people/5           
 
//访问sdcard/download/目录下的音频文件
//会利用系统提供的provider去读取文件
//从/data/data/com.android.providers.media/databases中的数据库表中访问
 
file:///sdcard/download/penglaoxi.mp3 

第二种用于访问网络资源，这里的scheme通常为http

http://www.baidu.com

第三种用于打电话等服务，这里的scheme通常为smsto和tel等

//44720673仅举例作用
tel:[phone]             //给44720673打电话
smsto：44720673    //给44720673发短信

二、UriMatcher匹配Uri

public static final int BOOK_DIR = 0;
public static final int BOOK_ITEM = 1;
 
//第一步，初始化
UriMatcher matcher = new UriMatcher(UriMatcher.NO_MATCH);  
 
//第二步，注册待匹配的Uri
matcher.addURI(AUTHORITY,"book",BOOK_DIR);
matcher.addURI(AUTHORITY,"book/#",BOOK_ITEM);
 
//第三步，进行匹配
Uri uri = Uri.parse("content://" + "com.example.yy" + "/book");  
int match = matcher.match(uri);  
       switch (match){
           case BOOK_DIR:  
               return "vnd.android.cursor.dir/book";  
           case BOOK_ITEM:  
               return "vnd.android.cursor.item/book";  
           default:  
               return null;  
       }  
//上面返回的是Uri对应的MIME

总结：matcher.match(uri)方法返回的是一个整数，这个整数是之前注册的时候定好的，uri就好比一个请求，我们先安排好哪个请求进来要干什么，在ContentProvider的CRUD方法中利用match()方法去匹配uri，针对不同的返回值采取不同的CRUD操作。

三、ContentUris处理Uri

ContentUris 有两个作用 ： 1、为路径加上ID 2、从Uri路径中获取ID

1. 为Uri路径加上ID：withAppendedId(uri, id)

//比如有这样一个Uri
Uri uri = Uri.parse("content://com.example.yy/book");
 
//通过ContentUris的withAppendedId()方法，为该Uri加上ID  
Uri resultUri = ContentUris.withAppendedId(uri, 10);
 
//最后resultUri为: 
//content://com.example.yy/book/10

2. 从Uri路径中获取ID—parseId(uri)

Uri uri = Uri.parse("content://com.example.yy/book/10")  
long bookId= ContentUris.parseId(uri);  

四、uri与file、path相互转化

（一）uri转file:

File file = new File(new URI(uri.toString()));

（二）file转uri

URI  uri = file.toURI();

（三）uri转path

private String getPath(Context context, Uri uri) {  
        String path = null;
        Cursor cursor = context.getContentResolver().query(uri, null, null, null, null);
        if (cursor == null) {
            return null;
        }
        if (cursor.moveToFirst()) {
            try {
                path = cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media.DATA));
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        cursor.close();
        return path;
 }  

（四）path转uri:

Uri uri = Uri.parse(path);  

（五）file转path:

String path = file.getPath();  

（六）path转file:

File file = new File(path);

五、常用Uri

//显示网页: 
  1. Uri uri = Uri.parse("http://www.google.com"); 
  2. Intent it = new Intent(Intent.ACTION_VIEW,uri); 
  3. startActivity(it); 
 
//显示地图: 
  1. Uri uri = Uri.parse("geo:38.899533,-77.036476"); 
  2. Intent it = new Intent(Intent.Action_VIEW,uri); 
  3. startActivity(it); 
 
//路径规划: 
  1. Uri uri = Uri.parse("http://maps.google.com/maps?f=d&saddr=startLat%20startLng&daddr=endLat%20endLng&hl=en"); 
  2. Intent it = new Intent(Intent.ACTION_VIEW,URI); 
  3. startActivity(it); 
 
//拨打电话: 
//调用拨号程序 
  1. Uri uri = Uri.parse("tel:xxxxxx"); 
  2. Intent it = new Intent(Intent.ACTION_DIAL, uri);   
  3. startActivity(it);   
  1. Uri uri = Uri.parse("tel.xxxxxx"); 
  2. Intent it =new Intent(Intent.ACTION_CALL,uri); 
  3. 要使用这个必须在配置文件中加入<uses-permission id="Android.permission.CALL_PHONE" /> 
 
//发送SMS/MMS 
//调用发送短信的程序 
  1. Intent it = new Intent(Intent.ACTION_VIEW); 
  2. it.putExtra("sms_body", "The SMS text"); 
  3. it.setType("vnd.android-dir/mms-sms"); 
  4. startActivity(it);   
//发送短信 
  1. Uri uri = Uri.parse("smsto:0800000123"); 
  2. Intent it = new Intent(Intent.ACTION_SENDTO, uri); 
  3. it.putExtra("sms_body", "The SMS text"); 
  4. startActivity(it);   
//发送彩信 
  1. Uri uri = Uri.parse("content://media/external/images/media/23"); 
  2. Intent it = new Intent(Intent.ACTION_SEND); 
  3. it.putExtra("sms_body", "some text"); 
  4. it.putExtra(Intent.EXTRA_STREAM, uri); 
  5. it.setType("image/png"); 
  6. startActivity(it); 
 
//发送Email 
  1. 
  2. Uri uri = Uri.parse("mailto:[e-mail]"); 
  3. Intent it = new Intent(Intent.ACTION_SENDTO, uri); 
  4. startActivity(it); 
  1. Intent it = new Intent(Intent.ACTION_SEND); 
  2. it.putExtra(Intent.EXTRA_EMAIL, "[e-mail]"); 
  3. it.putExtra(Intent.EXTRA_TEXT, "The email body text"); 
  4. it.setType("text/plain"); 
  5. startActivity(Intent.createChooser(it, "Choose Email Client"));   
  1. Intent it=new Intent(Intent.ACTION_SEND);   
  2. String[] tos={"[e-mail]"};   
  3. String[] ccs={"[e-mail]"};   
  4. it.putExtra(Intent.EXTRA_EMAIL, tos);   
  5. it.putExtra(Intent.EXTRA_CC, ccs);   
  6. it.putExtra(Intent.EXTRA_TEXT, "The email body text");   
  7. it.putExtra(Intent.EXTRA_SUBJECT, "The email subject text");   
  8. it.setType("message/rfc822");   
  9. startActivity(Intent.createChooser(it, "Choose Email Client")); 
 
//添加附件 
  1. Intent it = new Intent(Intent.ACTION_SEND); 
  2. it.putExtra(Intent.EXTRA_SUBJECT, "The email subject text"); 
  3. it.putExtra(Intent.EXTRA_STREAM, "[url=]file:///sdcard/mysong.mp3[/url]"); 
  4. sendIntent.setType("audio/mp3"); 
  5. startActivity(Intent.createChooser(it, "Choose Email Client")); 
 
//播放多媒体 
  1.   
  2. Intent it = new Intent(Intent.ACTION_VIEW); 
  3. Uri uri = Uri.parse("[url=]file:///sdcard/song.mp3[/url]"); 
  4. it.setDataAndType(uri, "audio/mp3"); 
  5. startActivity(it); 
  1. Uri uri = Uri.withAppendedPath(MediaStore.Audio.Media.INTERNAL_CONTENT_URI, "1"); 
  2. Intent it = new Intent(Intent.ACTION_VIEW, uri); 
  3. startActivity(it);   
 
//Uninstall 程序 
  1. Uri uri = Uri.fromParts("package", strPackageName, null); 
  2. Intent it = new Intent(Intent.ACTION_DELETE, uri); 
  3. startActivity(it); 
 
//调用相册 
public static final String MIME_TYPE_IMAGE_JPEG = "image/*"; 
public static final int ACTIVITY_GET_IMAGE = 0; 
Intent getImage = new Intent(Intent.ACTION_GET_CONTENT); 
getImage.addCategory(Intent.CATEGORY_OPENABLE); 
getImage.setType(MIME_TYPE_IMAGE_JPEG); 
startActivityForResult(getImage, ACTIVITY_GET_IMAGE); 
 
//调用系统相机应用程序，并存储拍下来的照片 
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); 
time = Calendar.getInstance().getTimeInMillis(); 
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(new File(Environment 
.getExternalStorageDirectory().getAbsolutePath()+"/tucue", time + ".jpg"))); 
startActivityForResult(intent, ACTIVITY_GET_CAMERA_IMAGE); 
 
uninstall apk 
/**未测试 
Uri uninstallUri = Uri.fromParts("package", "xxx", null); 
returnIt = new Intent(Intent.ACTION_DELETE, uninstallUri); 
*/ 
Uri packageURI = Uri.parse("package:"+wistatmap);   
Intent uninstallIntent = new Intent(Intent.ACTION_DELETE, packageURI);   
startActivity(uninstallIntent); 
 
install apk 
Uri installUri = Uri.fromParts("package", "xxx", null); 
returnIt = new Intent(Intent.ACTION_PACKAGE_ADDED, installUri); 
play audio 
Uri playUri = Uri.parse("[url=]file:///sdcard/download/everything.mp3[/url]"); 
returnIt = new Intent(Intent.ACTION_VIEW, playUri); 
 
//发送附件 
Intent it = new Intent(Intent.ACTION_SEND);   
it.putExtra(Intent.EXTRA_SUBJECT, "The email subject text");   
it.putExtra(Intent.EXTRA_STREAM, "[url=]file:///sdcard/eoe.mp3[/url]");   
sendIntent.setType("audio/mp3");   
startActivity(Intent.createChooser(it, "Choose Email Client")); 
 
//搜索应用 
Uri uri = Uri.parse("market://search?q=pname:pkg_name");   
Intent it = new Intent(Intent.ACTION_VIEW, uri);   
startActivity(it);   
//where pkg_name is the full package path for an application 
 
//进入联系人页面 
Intent intent = new Intent(); 
intent.setAction(Intent.ACTION_VIEW); 
intent.setData(People.CONTENT_URI); 
startActivity(intent); 
 
//查看指定联系人 
Uri personUri = ContentUris.withAppendedId(People.CONTENT_URI, info.id);//info.id联系人ID 
Intent intent = new Intent(); 
intent.setAction(Intent.ACTION_VIEW); 
intent.setData(personUri);
 
startActivity(intent);