手机里已经安装了email的apk,检查manitfest中也有对应的action,并且activity也没有被disable掉,为何就是找不到呢?
1.我下载了一个QQ邮箱安装到手机,发现ACTION_SENDTO启动QQ邮箱的设置界面
2.我把QQ邮箱卸载了,在原生Email里面登录一个账号,再ACTION_SENDTO可以启动对应的ComposeActivityEmail
3.那就是没有账号不能启动ComposeActivityEmail
4.ActivityStarter中startActivityMayWait的ResolveInfo rInfo = mSupervisor.resolveIntent(intent, resolvedType, userId);
和 ActivityInfo aInfo = mSupervisor.resolveActivity(intent, rInfo, startFlags, profilerInfo);当有账号rInfo 和aInfo 都不为null,当没有账号返回的是null.
5.通过分析得知ComposeActivityEmail是动态被enable和disable的,所以搜索setComponentEnabledSetting,找到了关键代码
http://androidxref.com/7.1.1_r6/xref/packages/apps/Email/provider_src/com/android/email/provider/AccountReconciler.java
if (!TextUtils.isEmpty(composeActivityName)) { // If there are no accounts remaining after reconciliation, disable the compose activity final boolean enableCompose = emailProviderAccounts.size() - accountsDeleted > 0; final ComponentName componentName = new ComponentName(context, composeActivityName); context.getPackageManager().setComponentEnabledSetting(componentName, enableCompose ? PackageManager.COMPONENT_ENABLED_STATE_ENABLED : PackageManager.COMPONENT_ENABLED_STATE_ENABLED, PackageManager.DONT_KILL_APP); LogUtils.d(LogUtils.TAG, "Setting compose activity to " + (enableCompose ? "enabled" : "disabled")); }
将这部分代码拿掉没有账号也可以启动email来处理sendto
具体为何google要这样做,目前还没有找到其理由。