LaunchMode

1. standard

• 系統(tǒng)默認(rèn)模式，每次啟動activity都會重新創(chuàng)建一個新的實例，在這種模式下誰啟動了standard的activity，那么這個activity就運行在啟動他的那個activity所在棧。

1：com.example.lzh_d.launchmodetest/.MainActivity

2：com.example.lzh_d.launchermodetest2/.MainActivity

3：com.example.lzh_d.launchermodetest2/.SecondActivity

1->2

1.2都是standard

    Running activities (most recent first):
      TaskRecord{af6f390 #3512 A=com.example.lzh_d.launchmodetest U=0 StackId=1 sz=2}
        Run #10: ActivityRecord{8ffb8bc u0 com.example.lzh_d.launchermodetest2/.MainActivity t3512}
        Run #9: ActivityRecord{6107fde u0 com.example.lzh_d.launchmodetest/.MainActivity t3512}
      TaskRecord{f5a8266 #3491 A=com.tencent.mm U=0 StackId=1 sz=1}
        Run #8: ActivityRecord{7a1cfe4 u0 com.tencent.mm/.ui.LauncherUI t3491}
      TaskRecord{fff18d2 #3509 A=com.example.lzh_d.launchermodetest2 U=0 StackId=1 sz=1}
        Run #7: ActivityRecord{2abdc4f u0 com.example.lzh_d.launchermodetest2/.MainActivity t3509}

2. singleTop

• 棧頂復(fù)用模式，如果新activity已經(jīng)位于任務(wù)棧的棧頂，那么此activity不會被重新創(chuàng)建，同時他的onNewIntent方法會被回調(diào)。
• 應(yīng)用場景，從通知啟動的activity，例如新聞內(nèi)容頁面，每次收到的新聞推送通知，都跳轉(zhuǎn)到相同的界面。

1>2，1是standard，2是singleTop,與standard相同

2->2

2已經(jīng)位于棧頂沒有被重新創(chuàng)建

    Running activities (most recent first):
      TaskRecord{ba16c5d #3522 A=com.example.lzh_d.launchermodetest2 U=0 StackId=1 sz=1}
        Run #2: ActivityRecord{e7c20de u0 com.example.lzh_d.launchermodetest2/.MainActivity t3522}
      TaskRecord{f3d9ce8 #3341 A=com.netease.newsreader.activity U=0 StackId=1 sz=1}
        Run #1: ActivityRecord{893c1a9 u0 com.netease.newsreader.activity/com.netease.nr.phone.main.MainActivity t3341}
      TaskRecord{8a730f7 #3180 A=com.android.incallui U=0 StackId=1 sz=1}
        Run #0: ActivityRecord{b389462 u0 com.android.incallui/.InCallScreen t3180}

對比standard

    Running activities (most recent first):
      TaskRecord{8249d5b #3520 A=com.example.lzh_d.launchermodetest2 U=0 StackId=1 sz=2}
        Run #2: ActivityRecord{2b9ad91 u0 com.example.lzh_d.launchermodetest2/.MainActivity t3520}
        Run #1: ActivityRecord{f40170f u0 com.example.lzh_d.launchermodetest2/.MainActivity t3520}
      TaskRecord{8a730f7 #3180 A=com.android.incallui U=0 StackId=1 sz=1}
        Run #0: ActivityRecord{b389462 u0 com.android.incallui/.InCallScreen t3180}

3. singleTask

• 棧內(nèi)復(fù)用模式，如果棧中存在此activity，那么將其調(diào)到棧頂，并且將其上的activity出棧。
• 應(yīng)用場景，主界面，不管我們打開多少個activity，只要我們再回到主界面，其按返回鍵都應(yīng)該退出應(yīng)用，比如在微博瀏覽一堆頁面會，回到主頁，應(yīng)該保證其上的activity都被移除，而不是在棧頂加一個新的主頁實例，這樣返回時不能退出應(yīng)用，反而回到之前的頁面。

1->2

1 standard,2 singleTask

    Running activities (most recent first):
      TaskRecord{c94e00b #3513 A=com.example.lzh_d.launchermodetest2 U=0 StackId=1 sz=1}
        Run #9: ActivityRecord{ffe3677 u0 com.example.lzh_d.launchermodetest2/.MainActivity t3513}
      TaskRecord{af6f390 #3512 A=com.example.lzh_d.launchmodetest U=0 StackId=1 sz=1}
        Run #8: ActivityRecord{6107fde u0 com.example.lzh_d.launchmodetest/.MainActivity t3512}
      TaskRecord{f5a8266 #3491 A=com.tencent.mm U=0 StackId=1 sz=1}
        Run #7: ActivityRecord{7a1cfe4 u0 com.tencent.mm/.ui.LauncherUI t3491}

1->2->3->2

1 standard,2 singleTask,3 standard

1啟動2后，1和2分別位于棧A，棧B,2再啟動3,3在棧B,3再啟動2,3出棧，棧B中只有2.

    Running activities (most recent first):
      TaskRecord{c5fb4e7 #3535 A=com.example.lzh_d.launchermodetest2 U=0 StackId=1 sz=1}
        Run #3: ActivityRecord{c101916 u0 com.example.lzh_d.launchermodetest2/.MainActivity t3535}
      TaskRecord{8ea71d7 #3525 A=com.example.lzh_d.launchmodetest U=0 StackId=1 sz=1}
        Run #2: ActivityRecord{3ecef32 u0 com.example.lzh_d.launchmodetest/.MainActivity t3525}
      TaskRecord{f3d9ce8 #3341 A=com.netease.newsreader.activity U=0 StackId=1 sz=1}
        Run #1: ActivityRecord{893c1a9 u0 com.netease.newsreader.activity/com.netease.nr.phone.main.MainActivity t3341}
      TaskRecord{8a730f7 #3180 A=com.android.incallui U=0 StackId=1 sz=1}
        Run #0: ActivityRecord{b389462 u0 com.android.incallui/.InCallScreen t3180}

4. singleInstance

• 單實例模式，系統(tǒng)唯一，單獨位于一個棧中。
• 來電呼叫界面，系統(tǒng)全局唯一的。還有就是分享界面，這種不需要跟別的界面在一個任務(wù)中的情況，如微信分享界面，在相冊中選擇一張圖片點擊分享到微信，這個微信分享選擇聯(lián)系人界面就是singleInstance，選擇聯(lián)系人后會開啟對話界面，然后在這個界面后退，會回到主界面而不是分享選擇聯(lián)系人界面。

1->2

這種情況和singleTask一樣

    Running activities (most recent first):
      TaskRecord{20c273e #3524 A=com.example.lzh_d.launchermodetest2 U=0 StackId=1 sz=1}
        Run #3: ActivityRecord{f624d33 u0 com.example.lzh_d.launchermodetest2/.MainActivity t3524}
      TaskRecord{8ea71d7 #3525 A=com.example.lzh_d.launchmodetest U=0 StackId=1 sz=1}
        Run #2: ActivityRecord{3ecef32 u0 com.example.lzh_d.launchmodetest/.MainActivity t3525}
      TaskRecord{f3d9ce8 #3341 A=com.netease.newsreader.activity U=0 StackId=1 sz=1}
        Run #1: ActivityRecord{893c1a9 u0 com.netease.newsreader.activity/com.netease.nr.phone.main.MainActivity t3341}
      TaskRecord{8a730f7 #3180 A=com.android.incallui U=0 StackId=1 sz=1}
        Run #0: ActivityRecord{b389462 u0 com.android.incallui/.InCallScreen t3180}

下面這種情況對比singleTask

1->2->3->2

1 standard,2 singleInstance,3 standard

1啟動2后，1和2分別位于棧A，棧B,2再啟動3,3在新建的棧C中,3再啟動2,找到棧B中的2，此時棧A，B，C分別放著activity 1 ，2 ，3.

    Running activities (most recent first):
      TaskRecord{2e79031 #3532 A=com.example.lzh_d.launchermodetest2 U=0 StackId=1 sz=1}
        Run #4: ActivityRecord{9f8d08f u0 com.example.lzh_d.launchermodetest2/.MainActivity t3532}
      TaskRecord{16d8316 #3533 A=com.example.lzh_d.launchermodetest2 U=0 StackId=1 sz=1}
        Run #3: ActivityRecord{898ffc9 u0 com.example.lzh_d.launchermodetest2/.SecondActivity t3533}
      TaskRecord{8ea71d7 #3525 A=com.example.lzh_d.launchmodetest U=0 StackId=1 sz=1}
        Run #2: ActivityRecord{3ecef32 u0 com.example.lzh_d.launchmodetest/.MainActivity t3525}
      TaskRecord{f3d9ce8 #3341 A=com.netease.newsreader.activity U=0 StackId=1 sz=1}
        Run #1: ActivityRecord{893c1a9 u0 com.netease.newsreader.activity/com.netease.nr.phone.main.MainActivity t3341}
      TaskRecord{8a730f7 #3180 A=com.android.incallui U=0 StackId=1 sz=1}
        Run #0: ActivityRecord{b389462 u0 com.android.incallui/.InCallScreen t3180}

singleTask與singleInstance區(qū)別：singleInstance 獨占一個棧，singleTask在棧中找到就置頂，并且其上activity出棧，可以和TaskAffinity聯(lián)合使用，指定所在任務(wù)棧。