android Intent

结构

componentName 组件
action
category 类别
Data Uri对象和数据的MIME类型,对应着Intent Filter中的data标签
type
extras 附加信息
Flags 标记启动Activity的方式

Intent的类型

explicit(显式)
- Intent(Context packageContext, Class<?>cls)
- ComponentName(Context pkg, Class<?> cls)
  public Intent setComponent (ComponentName component)

implict(隐式)

解析机制 : 目标组件的IntentFilter

action : action列表中必须包含相应action
category : category列表中必须包含相应category
type或data>type : data列表中必须包含相应type
没有指定type : data列表中必须包含Intent的scheme

<action android:name="com.example.project.SHOW_CURRENT" />
<category android:name="android.intent.category.DEFAULT" />
<data android:mimeType="video/mpeg" android:scheme="http" . . . /> 
<data android:mimeType="image/*" />
<data android:scheme="http" android:type="video/*" />
               
               
//先判断,再发出
// 获取包管理器
PackageManager pm = getPackageManager();
// 判断系统中有没有潜在的App的Activity支持对该sendIntent的接收与处理
if (pm.resolveActivity(sendIntent, 0) != null) {
    startActivity(sendIntent);
}

使用

传递数据

Bundle bundle=new Bundle();
bundle.putString("key", "This is from MainActivity!");
intent.putExtras(bundle);

//取出
Bundle bundle=getIntent().getExtras();
String name=bundle.getString("key");

启动activity


Intent intent = new Intent(MainActivity.this, Activity2.class);
//无返回
startActivity(intent);
//有返回
startActivityForResult(intent,REQUEST_CODE) 

//Activity2 设置返回结果
Intent intent=getIntent();
Bundle bundle2=new Bundle();
bundle2.putString("key", "This is from ShowMsg!");
intent.putExtras(bundle2);
setResult(RESULT_OK, intent);


//MainActivity 处理返回结果
//回调上一个Activity的结果处理函数
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    // TODO Auto-generated method stub
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode==REQUEST_CODE){
        if(resultCode==RESULT_CANCELED){
                setTitle("cancle");
        }
        else if (resultCode==RESULT_OK) {
                String temp=null;
                Bundle bundle=data.getExtras();
                if(bundle!=null)   temp=bundle.getString("key");
                setTitle(temp);
        }
    }
}

启动service

action

intent最多只能定义1个action
filter可以定义1个或多个action
Intent.ACTION_VIEW
Intent.ACTION_SEND

data

setData()方法和setType()互斥
setDataAndType()

Extras

intent.putExtra(key, value)
intent.putExtras(Bundle)

Flags

FLAG_ACTIVITY_NEW_TASK
通知系统将目标activity作为一个新task的初始activity
FLAG_ACTIVITY_NO_HISTORY
通知系统在目标activity退出栈顶时,不要保存在栈中
FLAG_FROM_BACKGROUND
通知系统这个Intent来源于后台操作, 而非用户的直接选择

使用

显示网页

Uri uri = Uri.parse("http://google.com");  
Intent it = new Intent(Intent.ACTION_VIEW, uri);  
startActivity(it);

显示地图

Uri uri = Uri.parse("geo:38.899533,-77.036476");  
Intent it = new Intent(Intent.ACTION_VIEW, uri);   
startActivity(it);

路径规划

Uri uri = Uri.parse("http://maps.google.com/maps?f=d&saddr=startLat%20startLng&daddr=endLat%20endLng&hl=en");  
Intent it = new Intent(Intent.ACTION_VIEW, uri);  
startActivity(it);  
//startLat, startLng, endLat, endLng are a long with 6 decimals

打电话

 //唤出拨号程序 
Uri uri = Uri.parse("tel:0800000123");  
Intent it = new Intent(Intent.ACTION_DIAL, uri);  
startActivity(it);  
//直接打电话出去  
Uri uri = Uri.parse("tel:0800000123");  
Intent it = new Intent(Intent.ACTION_CALL, uri);  
startActivity(it);  
//<uses-permission id="android.permission.CALL_PHONE" />

传送SMS/MMS

//调用短信程序 
Intent it = new Intent(Intent.ACTION_VIEW, uri);  
it.putExtra("sms_body", "The SMS text");   
it.setType("vnd.android-dir/mms-sms");  
startActivity(it); 
//传送消息 
Uri uri = Uri.parse("smsto://0800000123");  
Intent it = new Intent(Intent.ACTION_SENDTO, uri);  
it.putExtra("sms_body", "The SMS text");  
startActivity(it); 
//传送 MMS  
Uri uri = Uri.parse("content://media/external/images/media/23");  
Intent it = new Intent(Intent.ACTION_SEND);   
it.putExtra("sms_body", "some text");   
it.putExtra(Intent.EXTRA_STREAM, uri);  
it.setType("image/png");   
startActivity(it);

Uri uri = Uri.parse("mailto:xxx@abc.com");  
Intent it = new Intent(Intent.ACTION_SENDTO, uri);  
startActivity(it); 


Intent it = new Intent(Intent.ACTION_SEND);  
it.putExtra(Intent.EXTRA_EMAIL, "me@abc.com");  
it.putExtra(Intent.EXTRA_TEXT, "The email body text");  
it.setType("text/plain");  
startActivity(Intent.createChooser(it, "Choose Email Client")); 


Intent it=new Intent(Intent.ACTION_SEND);    
String[] tos={"me@abc.com"};    
String[] ccs={"you@abc.com"};    
it.putExtra(Intent.EXTRA_EMAIL, tos);    
it.putExtra(Intent.EXTRA_CC, ccs);    
it.putExtra(Intent.EXTRA_TEXT, "The email body text");    
it.putExtra(Intent.EXTRA_SUBJECT, "The email subject text");    
it.setType("message/rfc822");    
startActivity(Intent.createChooser(it, "Choose Email Client"));


//传送附件
Intent it = new Intent(Intent.ACTION_SEND);  
it.putExtra(Intent.EXTRA_SUBJECT, "The email subject text");  
it.putExtra(Intent.EXTRA_STREAM, "file:///sdcard/mysong.mp3");  
sendIntent.setType("audio/mp3");  
startActivity(Intent.createChooser(it, "Choose Email Client"));

多媒体

Uri uri = Uri.parse("file:///sdcard/song.mp3");  
Intent it = new Intent(Intent.ACTION_VIEW, uri);  
it.setType("audio/mp3");  
startActivity(it); 
      
      
Uri uri = Uri.withAppendedPath(MediaStore.Audio.Media.INTERNAL_CONTENT_URI, "1");  
Intent it = new Intent(Intent.ACTION_VIEW, uri);  
startActivity(it);

market

//寻找某个应用 
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 
//显示某个应用的相关信息 
Uri uri = Uri.parse("market://details?id=app_id");  
Intent it = new Intent(Intent.ACTION_VIEW, uri); 
startActivity(it);  
//where app_id is the application ID, find the ID   
//by clicking on your application on Market home   
//page, and notice the ID from the address bar

Uninstall

Uri uri = Uri.fromParts("package", strPackageName, null); 
Intent it = new Intent(Intent.ACTION_DELETE, uri);   
startActivity(it);