android app 不显示home键,[实践] Android源码 - 阻止APP被长按HOME键方式结束掉

[实践] Android源码 - 阻止APP被长按HOME键方式结束掉

@(Android研究)[阻止APP被系统结束]

[TOC]

前言

本文只讲做法，不讲理论。

实践

系统：Android5.1.1

当前实践修改了Android5.1.1的源码。

假设APP包名为"com.a.b.c"，让包名为"com.a.b.c"的APP进程不被系统结束掉。

找到ActivityManagerService.cleanUpRemovedTaskLocked方法所在的文件"frameworks/base/services/core/java/com/android/server/am/ActivityManagerService.java"，下面对是ActivityManagerService.cleanUpRemovedTaskLocked方法修改后的代码：

private void cleanUpRemovedTaskLocked(TaskRecord tr, boolean killProcess) {

mRecentTasks.remove(tr);

tr.removedFromRecents();

ComponentName component = tr.getBaseIntent().getComponent();

if (component == null) {

Slog.w(TAG, "No component for base intent of task: " + tr);

return;

}

if (!killProcess) {

return;

}

// Determine if the process(es) for this task should be killed.

final String pkg = component.getPackageName();

// 新添加的代码。

if("com.a.b.c".equals(pkg)) {

return;

}

ArrayList procsToKill = new ArrayList();

ArrayMap> pmap = mProcessNames.getMap();

for (int i = 0; i < pmap.size(); i++) {

SparseArray uids = pmap.valueAt(i);

for (int j = 0; j < uids.size(); j++) {

// 在这里做了一些判断，判断哪些任务不被结束。

ProcessRecord proc = uids.valueAt(j);

if (proc.userId != tr.userId) {

// Don't kill process for a different user.

continue;

}

if (proc == mHomeProcess) {

// Don't kill the home process along with tasks from the same package.

continue;

}

if (!proc.pkgList.containsKey(pkg)) {

// Don't kill process that is not associated with this task.

continue;

}

for (int k = 0; k < proc.activities.size(); k++) {

TaskRecord otherTask = proc.activities.get(k).task;

if (tr.taskId != otherTask.taskId && otherTask.inRecents) {

// Don't kill process(es) that has an activity in a different task that is

// also in recents.

return;

}

}

// 除了不被删除的任务，剩下的任务都可以被结束。

// Add process to kill list.

procsToKill.add(proc);

}

}

// Find any running services associated with this app and stop if needed.

mServices.cleanUpRemovedTaskLocked(tr, component, new Intent(tr.getBaseIntent()));

// 结束进程

// Kill the running processes.

for (int i = 0; i < procsToKill.size(); i++) {

ProcessRecord pr = procsToKill.get(i);

if (pr.setSchedGroup == Process.THREAD_GROUP_BG_NONINTERACTIVE) {

pr.kill("remove task", true);

} else {

pr.waitingToKill = "remove task";

}

}

}

下面是ActivityManagerService.cleanUpRemovedTaskLocked方法的源码：

private void cleanUpRemovedTaskLocked(TaskRecord tr, boolean killProcess) {

mRecentTasks.remove(tr);

tr.removedFromRecents();

ComponentName component = tr.getBaseIntent().getComponent();

if (component == null) {

Slog.w(TAG, "No component for base intent of task: " + tr);

return;

}

if (!killProcess) {

return;

}

// Determine if the process(es) for this task should be killed.

final String pkg = component.getPackageName();

ArrayList procsToKill = new ArrayList();

ArrayMap> pmap = mProcessNames.getMap();

for (int i = 0; i < pmap.size(); i++) {

SparseArray uids = pmap.valueAt(i);

for (int j = 0; j < uids.size(); j++) {

// 在这里做了一些判断，判断哪些任务不被结束。

ProcessRecord proc = uids.valueAt(j);

if (proc.userId != tr.userId) {

// Don't kill process for a different user.

continue;

}

if (proc == mHomeProcess) {

// Don't kill the home process along with tasks from the same package.

continue;

}

if (!proc.pkgList.containsKey(pkg)) {

// Don't kill process that is not associated with this task.

continue;

}

for (int k = 0; k < proc.activities.size(); k++) {

TaskRecord otherTask = proc.activities.get(k).task;

if (tr.taskId != otherTask.taskId && otherTask.inRecents) {

// Don't kill process(es) that has an activity in a different task that is

// also in recents.

return;

}

}

// 除了不被删除的任务，剩下的任务都可以被结束。

// Add process to kill list.

procsToKill.add(proc);

}

}

// Find any running services associated with this app and stop if needed.

mServices.cleanUpRemovedTaskLocked(tr, component, new Intent(tr.getBaseIntent()));

// 结束进程

// Kill the running processes.

for (int i = 0; i < procsToKill.size(); i++) {

ProcessRecord pr = procsToKill.get(i);

if (pr.setSchedGroup == Process.THREAD_GROUP_BG_NONINTERACTIVE) {

pr.kill("remove task", true);

} else {

pr.waitingToKill = "remove task";

}

}

}

实践二

系统：Android4.4.4_r2

当前实践修改了Android4.4.4_r2的源码。

找到ActivityManagerService.cleanUpRemovedTaskLocked方法所在的文件"frameworks/base/services/core/java/com/android/server/am/ActivityManagerService.java"，下面是ActivityManagerService.cleanUpRemovedTaskLocked方法的源码：

private void cleanUpRemovedTaskLocked(TaskRecord tr, int flags) {

tr.disposeThumbnail();

mRecentTasks.remove(tr);

final boolean killProcesses = (flags&ActivityManager.REMOVE_TASK_KILL_PROCESS) != 0;

Intent baseIntent = new Intent(

tr.intent != null ? tr.intent : tr.affinityIntent);

ComponentName component = baseIntent.getComponent();

if (component == null) {

Slog.w(TAG, "Now component for base intent of task: " + tr);

return;

}

......

if (killProcesses) {

......

}

}

通过观察上面的源码可以发现当killProcesses为true时将会执行清理代码，当killProcesses为false时则不会执行清理代码，而killProcesses是否为true与ActivityManager.REMOVE_TASK_KILL_PROCESS标志相关。

下面是对ActivityManagerService.cleanUpRemovedTaskLocked方法修改后的代码：

private void cleanUpRemovedTaskLocked(TaskRecord tr, int flags) {

flags = flags&ActivityManager.REMOVE_TASK_KILL_PROCESS;

tr.disposeThumbnail();

mRecentTasks.remove(tr);

final boolean killProcesses = (flags&ActivityManager.REMOVE_TASK_KILL_PROCESS) != 0;

Intent baseIntent = new Intent(

tr.intent != null ? tr.intent : tr.affinityIntent);

ComponentName component = baseIntent.getComponent();

if (component == null) {

Slog.w(TAG, "Now component for base intent of task: " + tr);

return;

}

......

if (killProcesses) {

......

}

}