概述

Intent是用于和其他應(yīng)用組件通信的消息對(duì)象，

通常有三種用途：啟動(dòng)Activity啸罢、啟動(dòng)Service裳朋、發(fā)送Broadcast

Intent類型

• 顯式Intent
• 隱式Intent

創(chuàng)建Intent

• Component name

  • setComponent()
  • setClass()
  • setClassName()

• Action

  • ACTION_VIEW
  • ACTION_SEND

• Data

  Uri對(duì)象、指定數(shù)據(jù)的MIME類型

  • setDataAndType()

• Category

  • CATEGORY_BROWSABLE
  • CATEGORY_LAUNCHER

• Extras

  Bundle鍵值對(duì)

• Flags

  指示如何啟動(dòng)Activity温学，以及啟動(dòng)后它所屬的任務(wù)棧

示例: App選擇器

val sendIntent = Intent(Intent.ACTION_SEND)
...

// Always use string resources for UI text.
// This says something like "Share this photo with"
val title: String = resources.getString(R.string.chooser_title)
// Create intent to show the chooser dialog
val chooser: Intent = Intent.createChooser(sendIntent, title)

// Verify the original intent will resolve to at least one activity
if (sendIntent.resolveActivity(packageManager) != null) {
    startActivity(chooser)
}

接收隱式Intent

清單文件中定義<intent-filter>

- <action>
- <data>
- <category>

<activity android:name="MainActivity">
    <!-- This activity is the main entry, should appear in app launcher -->
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

<activity android:name="ShareActivity">
    <!-- This activity handles "SEND" actions with text data -->
    <intent-filter>
        <action android:name="android.intent.action.SEND"/>
        <category android:name="android.intent.category.DEFAULT"/>
        <data android:mimeType="text/plain"/>
    </intent-filter>
    <!-- This activity also handles "SEND" and "SEND_MULTIPLE" with media data -->
    <intent-filter>
        <action android:name="android.intent.action.SEND"/>
        <action android:name="android.intent.action.SEND_MULTIPLE"/>
        <category android:name="android.intent.category.DEFAULT"/>
        <data android:mimeType="application/vnd.google.panorama360+jpg"/>
        <data android:mimeType="image/*"/>
        <data android:mimeType="video/*"/>
    </intent-filter>
</activity>

PendingIntent

使用場景：

- Notification
- App Widget
- AlarmManager

創(chuàng)建：

- PendingIntent.getActivity()
- PendingIntent.getService()
- PendingIntent.getBroadcast()

<font color="red">解析Intent</font>

• action

  Intent中指定的action必須與intent-filter中列出的action一項(xiàng)匹配聪建。

  若intent-filter中不包含action钙畔，匹配永遠(yuǎn)不會(huì)成功。

  若Intent中未指定action金麸，而只要intent-filter至少包含一個(gè)action就會(huì)默認(rèn)匹配成功擎析。

• category

  Intent中的每個(gè)category都必須與intent-filter中列出的category匹配。

  即Intent中指定的category必須是intent-filter中category的子集挥下。

  若Intent不包含category揍魂，則匹配成功。

• data

  1. 僅當(dāng)過濾器未指定任何 URI 或 MIME 類型時(shí)棚瘟，不含 URI 和 MIME 類型的 Intent 才會(huì)通過測試现斋。
  2. 對(duì)于包含 URI 但不含 MIME 類型（既未顯式聲明，也無法通過 URI 推斷得出）的 Intent偎蘸，僅當(dāng)其 URI 與過濾器的 URI 格式匹配庄蹋、且過濾器同樣未指定 MIME 類型時(shí)，才會(huì)通過測試迷雪。
  3. 僅當(dāng)過濾器列出相同的 MIME 類型且未指定 URI 格式時(shí)限书，包含 MIME 類型但不含 URI 的 Intent 才會(huì)通過測試。
  4. 如果過濾器只是列出 MIME 類型章咧，則假定組件支持 content: 和 file: 數(shù)據(jù)倦西。

Intent匹配

PackageManager 提供一整套 query...() 方法來返回所有能夠接受特定 Intent 的組件。

此外赁严，還會(huì)提供一系列類似的 resolve...() 方法來確定響應(yīng) Intent 的最佳組件扰柠。

常見Intent

鬧鐘

• Action：ACTION_SET_ALARM
• Extras
  • EXTRA_HOUR
  • EXTRA_MINUTES
  • EXTRA_MESSAGE
  • EXTRA_DAYS
  • EXTRA_RINGTONE
  • EXTRA_VIBRATE
  • EXTRA_SKIP_UI

//SET_ALARM permission 
fun createAlarm(message: String, hour: Int, minutes: Int) {
    val intent = Intent(AlarmClock.ACTION_SET_ALARM).apply {
        putExtra(AlarmClock.EXTRA_MESSAGE, message)
        putExtra(AlarmClock.EXTRA_HOUR, hour)
        putExtra(AlarmClock.EXTRA_MINUTES, minutes)
    }
    if (intent.resolveActivity(packageManager) != null) {
        startActivity(intent)
    }
}

定時(shí)器

• Action：ACTION_SET_TIMER
• Extras：
  • EXTRA_LENGTH
  • EXTRA_MESSAGE
  • EXTRA_SKIP_UI

//SET_ALARM permission
fun startTimer(message: String, seconds: Int) {
    val intent = Intent(AlarmClock.ACTION_SET_TIMER).apply {
        putExtra(AlarmClock.EXTRA_MESSAGE, message)
        putExtra(AlarmClock.EXTRA_LENGTH, seconds)
        putExtra(AlarmClock.EXTRA_SKIP_UI, true)
    }
    if (intent.resolveActivity(packageManager) != null) {
        startActivity(intent)
    }
}

顯示所有鬧鐘

• Action：ACTION_SHOW_ALARMS

日歷

• Action：ACTION_INSERT
• Data URI：Events.CONTENT_URI
• MIME Type：“vnd.android.cursor.dir/event”
• Extra：
  • EXTRA_EVENT_ALL_DAY
  • EXTRA_EVENT_BEGIN_TIME
  • EXTRA_EVENT_END_TIME
  • TITLE
  • DESCRIPTION
  • EVENT_LOCATION
  • EXTRA_EMAIL

fun addEvent(title: String, location: String, begin: Long, end: Long) {
    val intent = Intent(Intent.ACTION_INSERT).apply {
        data = Events.CONTENT_URI
        putExtra(Events.TITLE, title)
        putExtra(Events.EVENT_LOCATION, location)
        putExtra(CalendarContract.EXTRA_EVENT_BEGIN_TIME, begin)
        putExtra(CalendarContract.EXTRA_EVENT_END_TIME, end)
    }
    if (intent.resolveActivity(packageManager) != null) {
        startActivity(intent)
    }
}

相機(jī)

拍攝照片或視頻

相對(duì)于相機(jī)應(yīng)用粉铐，此界面只要拍攝功能，無相冊

• Action：ACTION_IMAGE_CAPTURE or ACTION_VIDEO_CAPTURE
• Extras：EXTRA_OUTPUT

const val REQUEST_IMAGE_CAPTURE = 1
val locationForPhotos: Uri = ...

fun capturePhoto(targetFilename: String) {
    val intent = Intent(MediaStore.ACTION_IMAGE_CAPTURE).apply {
        putExtra(MediaStore.EXTRA_OUTPUT, Uri.withAppendedPath(locationForPhotos, targetFilename))
    }
    if (intent.resolveActivity(packageManager) != null) {
        startActivityForResult(intent, REQUEST_IMAGE_CAPTURE)
    }
}

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent) {
    if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == Activity.RESULT_OK) {
        val thumbnail: Bitmap = data.getParcelableExtra("data")
        // Do other work with full size photo saved in locationForPhotos
        ...
    }
}

For more information about how to use this intent to capture a photo, including how to create an appropriate Uri for the output location, read Taking Photos Simply or Taking Videos Simply.

啟動(dòng)相機(jī)應(yīng)用

• INTENT_ACTION_STILL_IMAGE_CAMERA
• INTENT_ACTION_VIDEO_CAMERA

聯(lián)系人

選擇聯(lián)系人

• Action：ACTION_PICK
• MIME Type：Contacts.CONTENT_TYPE

選擇特定聯(lián)系人數(shù)據(jù)

• Action：ACTION_PICK
• MIME Type：
  • CommonDataKinds.Phone.CONTNET_TYPE
  • CommonDataKinds.Email.CONTNET_TYPE

const val REQUEST_SELECT_PHONE_NUMBER = 1

fun selectContact() {
    // Start an activity for the user to pick a phone number from contacts
    val intent = Intent(Intent.ACTION_PICK).apply {
        type = CommonDataKinds.Phone.CONTENT_TYPE   
    }
    if (intent.resolveActivity(packageManager) != null) {
        startActivityForResult(intent, REQUEST_SELECT_PHONE_NUMBER)
    }
}

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent) {
    if (requestCode == REQUEST_SELECT_PHONE_NUMBER && resultCode == Activity.RESULT_OK) {
        // Get the URI and query the content provider for the phone number
        val contactUri: Uri = data.data
        val projection: Array<String> = arrayOf(CommonDataKinds.Phone.NUMBER)
        contentResolver.query(contactUri, projection, null, null, null).use { cursor ->
            // If the cursor returned is valid, get the phone number
            if (cursor.moveToFirst()) {
                val numberIndex = cursor.getColumnIndex(CommonDataKinds.Phone.NUMBER)
                val number = cursor.getString(numberIndex)
                // Do something with the phone number
                ...
            }
        }
    }
}

查看聯(lián)系人

• Action：ACTION_VIEW
• Data URI：content:<URI>

fun viewContact(contactUri: Uri) {
    val intent = Intent(Intent.ACTION_VIEW, contactUri)
    if (intent.resolveActivity(packageManager) != null) {
        startActivity(intent)
    }
}

編輯現(xiàn)有聯(lián)系人

• Action：ACTION_EDIT
• Data URI：content:<URI>
• MIME Type：該類型是從聯(lián)系人 URI 推斷得出
• Extra：ContactsContract.Intents.Insert

fun editContact(contactUri: Uri, email: String) {
    val intent = Intent(Intent.ACTION_EDIT).apply {
        data = contactUri
        putExtra(ContactsContract.Intents.Insert.EMAIL, email)
    }
    if (intent.resolveActivity(packageManager) != null) {
        startActivity(intent)
    }
}

插入聯(lián)系人

• Action：ACTION_INSERT
• MIME Type：Contacts.CONTENT_TYPE
• Extra：ContactsContract.Intents.Insert

fun insertContact(name: String, email: String) {
    val intent = Intent(Intent.ACTION_INSERT).apply {
        type = ContactsContract.Contacts.CONTENT_TYPE
        putExtra(ContactsContract.Intents.Insert.NAME, name)
        putExtra(ContactsContract.Intents.Insert.EMAIL, email)
    }
    if (intent.resolveActivity(packageManager) != null) {
        startActivity(intent)
    }
}

電子郵件

文件存儲(chǔ)

檢索特定類型的文件

• Action：ACTION_GET_CONTENT
• MIME Type：文件對(duì)應(yīng)類型
• Extra：
  • EXTRA_ALLOW_MULTIPLE
  • EXTRA_LOCAL_ONLY
• Category（可選）：CATEGORY_OPENABLE

//獲取照片
const val REQUEST_IMAGE_GET = 1

fun selectImage() {
    val intent = Intent(Intent.ACTION_GET_CONTENT).apply {
        type = "image/*"
    }
    if (intent.resolveActivity(packageManager) != null) {
        startActivityForResult(intent, REQUEST_IMAGE_GET)
    }
}

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent) {
    if (requestCode == REQUEST_IMAGE_GET && resultCode == Activity.RESULT_OK) {
        val thumbnail: Bitmap = data.getParcelableExtra("data")
        val fullPhotoUri: Uri = data.data
        // Do work with photo saved at fullPhotoUri
        ...
    }
}

打開特定類型的文件

• Action：ACTION_OPEN_DOCUMENT or ACTION_CREATE_DOCUMENT

• MIME Type：文件對(duì)應(yīng)類型

• Extra：

  • EXTRA_MIME_TYPES
  • EXTRA_ALLOW_MULTIPLE
  • EXTRA_TITLE
  • EXTRA_LOCAL_ONLY

• Category：CATEGORY_OPENABLE

//獲取照片2
const val REQUEST_IMAGE_OPEN = 1

fun selectImage2() {
    val intent = Intent(Intent.ACTION_OPEN_DOCUMENT).apply {
        type = "image/*"
        addCategory(Intent.CATEGORY_OPENABLE)
    }
    // Only the system receives the ACTION_OPEN_DOCUMENT, so no need to test.
    startActivityForResult(intent, REQUEST_IMAGE_OPEN)
}

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent) {
    if (requestCode == REQUEST_IMAGE_OPEN && resultCode == Activity.RESULT_OK) {
        val fullPhotoUri: Uri = data.data
        // Do work with full size photo saved at fullPhotoUri
        ...
    }
}

地圖

• Action：ACTION_VIEW

• Data URI：

  • geo:latitude,longitude

    顯示給定經(jīng)緯度地圖

  • geo:latitude,longitude?z=zoom

    按照特定縮放級(jí)別顯示（1-23耻矮，1為全球地圖秦躯，23為最高精度縮放）

  • geo:0,0?q=lat,lng(label)

    顯示給定經(jīng)緯度處帶字符串標(biāo)簽的地圖

  • geo:0,0?q=my+street+address

    顯示“我的街道”位置

fun showMap(geoLocation: Uri) {
    val intent = Intent(Intent.ACTION_VIEW).apply {
        data = geoLocation
    }
    if (intent.resolveActivity(packageManager) != null) {
        startActivity(intent)
    }
}

音樂或視頻

播放媒體文件

• Action：ACTION_VIEW
• Data URI：
  • file:<URI>
  • content:<URI>
  • http:<URI>
• MIME Type:
  • "audio/*"
  • "application/ogg"
  • "application/x-ogg"
  • "application/itunes"

fun playMedia(file: Uri) {
    val intent = Intent(Intent.ACTION_VIEW).apply {
        data = file
    }
    if (intent.resolveActivity(packageManager) != null) {
        startActivity(intent)
    }
}

基于搜索播放音樂

• Action：INTENT_ACTION_MEDIA_PLAY_FROM_SEARCH
• Extra：MediaStore.EXTRA_MEDIA_FOCUS

fun playSearchArtist(artist: String) {
    val intent = Intent(MediaStore.INTENT_ACTION_MEDIA_PLAY_FROM_SEARCH).apply {
        putExtra(MediaStore.EXTRA_MEDIA_FOCUS, MediaStore.Audio.Artists.ENTRY_CONTENT_TYPE)
        putExtra(MediaStore.EXTRA_MEDIA_ARTIST, artist)
        putExtra(SearchManager.QUERY, artist)
    }
    if (intent.resolveActivity(packageManager) != null) {
        startActivity(intent)
    }
}

新筆記

• Action：ACTION_CREATE_NOTE
• MIME Type：PLAIN_TEXT_TYPE
• Extra：
  • EXTRA_NAME
  • EXTRA_TEXT

fun createNote(subject: String, text: String) {
    val intent = Intent(NoteIntents.ACTION_CREATE_NOTE).apply {
        putExtra(NoteIntents.EXTRA_NAME, subject)
        putExtra(NoteIntents.EXTRA_TEXT, text)
    }
    if (intent.resolveActivity(packageManager) != null) {
        startActivity(intent)
    }
}

電話

• Action：
  • ACTION_DIAL 打開撥號(hào)界面
  • ACTION_CALL 撥打電話（需要CALL_PHONE權(quán)限）
• Data URI：
  • tel:<phone-number>
  • voicemail:<phone-number>

fun dialPhoneNumber(phoneNumber: String) {
    val intent = Intent(Intent.ACTION_DIAL).apply {
        data = Uri.parse("tel:$phoneNumber")
    }
    if (intent.resolveActivity(packageManager) != null) {
        startActivity(intent)
    }
}

網(wǎng)頁搜索

• Action：ACTION_WEB_SEARCH
• Extra：SearchManager.QUERY 搜索字符串

fun searchWeb(query: String) {
    val intent = Intent(Intent.ACTION_WEB_SEARCH).apply {
        putExtra(SearchManager.QUERY, query)
    }
    if (intent.resolveActivity(packageManager) != null) {
        startActivity(intent)
    }
}

設(shè)置

• Action：
  • ACTION_SETTINGS
  • ACTION_WIRELESS_SETTINGS
  • ACTION_AIRPLANE_MODE_SETTINGS
  • ACTION_WIFI_SETTINGS
  • ACTION_APN_SETTINGS
  • ACTION_BLUETOOTH_SETTINGS
  • ACTION_DATE_SETTINGS
  • ACTION_LOCALE_SETTINGS
  • ACTION_INPUT_METHOD_SETTINGS
  • ACTION_DISPLAY_SETTINGS
  • ACTION_SECURITY_SETTINGS
  • ACTION_LOCATION_SOURCE_SETTINGS
  • ACTION_INTERNAL_STORAGE_SETTINGS
  • ACTION_MEMORY_CARD_SETTINGS

fun openWifiSettings() {
    val intent = Intent(Settings.ACTION_WIFI_SETTINGS)
    if (intent.resolveActivity(packageManager) != null) {
        startActivity(intent)
    }
}

發(fā)短信

• Action：
  • ACTION_SENDTO
  • ACTION_SEND
  • ACTION_SEND_MULTIPLE
• Data URI：
  • sms:<phone_number>
  • smsto:<phone_number>
  • mms:<phone_number>
  • mmsto:<phone_number>
• MIME Type:
  • "text/plain"
  • "image/*"
  • "video/*"
• Extra
  • "subject"
  • "sms_body"
  • EXTRA_STREAM

fun composeMmsMessage(message: String, attachment: Uri) {
    val intent = Intent(Intent.ACTION_SEND).apply {
        data = Uri.parse("smsto:")  // This ensures only SMS apps respond
        putExtra("sms_body", message)
        putExtra(Intent.EXTRA_STREAM, attachment)
    }
    if (intent.resolveActivity(packageManager) != null) {
        startActivity(intent)
    }
}

網(wǎng)頁瀏覽器

• Action：ACTION_VIEW
• Data URI：
  • http:<URL>
  • https:<URL>
• MIME Type：
  • "text/plain"
  • "text/html"
  • "application/xhtml+xml"
  • "application/vnd.wap.xhtml+xml"

fun openWebPage(url: String) {
    val webpage: Uri = Uri.parse(url)
    val intent = Intent(Intent.ACTION_VIEW, webpage)
    if (intent.resolveActivity(packageManager) != null) {
        startActivity(intent)
    }
}

示例intent-filter

<activity ...>
    <intent-filter>
        <action android:name="android.intent.action.VIEW" />
        <!-- Include the host attribute if you want your app to respond
             only to URLs with your app's domain. -->
        <data android:scheme="http" android:host="www.example.com" />
        <category android:name="android.intent.category.DEFAULT" />
        <!-- The BROWSABLE category is required to get links from web pages. -->
        <category android:name="android.intent.category.BROWSABLE" />
    </intent-filter>
</activity>

使用adb調(diào)試Intent

adb shell am start -a <ACTION> -t <MIME_TYPE> -d <DATA> \
  -e <EXTRA_NAME> <EXTRA_VALUE> -n <ACTIVITY>

如：

adb shell am start -a android.intent.action.DIAL \
  -d tel:555-5555 -n org.example.MyApp/.MyActivity