[无障碍]服务 accessibilityservice 初识

1.无障碍模式

Android 6.0 后的运行时权限，有时我们不想让用户手动点击，这时我们就可以使用 accessibilityservice 来监测窗口时间，自动完成运行时权限确定或者自动安装应用程序，同时也是微信抢红包的原理

2.设置源码

1.-------------------------------------------------------------------------------------
通过字符串找界面

    <string name="accessibility_settings" msgid="3975902491934816215">"无障碍"</string>

2.-------------------------------------------------------------------------------------
布局文件
accessibility_settings.xml
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:settings="http://schemas.android.com/apk/res/com.android.settings"
        android:title="@string/accessibility_settings"【"无障碍"】
        android:persistent="true">

    <PreferenceCategory
            android:key="services_category"
            android:title="@string/accessibility_services_title">【服务】
    </PreferenceCategory>

3.-------------------------------------------------------------------------------------
搜索services_category字符串

AccessibilitySettings.java (3 matches)

package com.android.settings.accessibility;

/**
 * Activity with the accessibility settings.
 */
public class AccessibilitySettings extends SettingsPreferenceFragment implements DialogCreatable,
        Preference.OnPreferenceChangeListener, Indexable {

    // Preference categories
    private static final String SERVICES_CATEGORY = "services_category";

    private void initializeAllPreferences() {
        mServicesCategory = (PreferenceCategory) findPreference(SERVICES_CATEGORY);
        ...

4.-------------------------------------------------------------------------------------
遍历 <action android:name="android.accessibilityservice.AccessibilityService"/> 的应用清单

    private void updateServicesPreferences() {
        // Since services category is auto generated we have to do a pass
        // to generate it since services can come and go and then based on
        // the global accessibility state to decided whether it is enabled.

        // Generate.
        mServicesCategory.removeAll();

        AccessibilityManager accessibilityManager = AccessibilityManager.getInstance(getActivity());

        List<AccessibilityServiceInfo> installedServices =
                accessibilityManager.getInstalledAccessibilityServiceList();
        Set<ComponentName> enabledServices = AccessibilityUtils.getEnabledServicesFromSettings(
                getActivity());
        List<String> permittedServices = mDpm.getPermittedAccessibilityServices(
                UserHandle.myUserId());
        final boolean accessibilityEnabled = Settings.Secure.getInt(getContentResolver(),
                Settings.Secure.ACCESSIBILITY_ENABLED, 0) == 1;

        for (int i = 0, count = installedServices.size(); i < count; ++i) {
            AccessibilityServiceInfo info = installedServices.get(i);

            RestrictedPreference preference = new RestrictedPreference(getActivity());
            preference.setLayoutResource(R.layout.preference_material_settings);
            String title = info.getResolveInfo().loadLabel(getPackageManager()).toString();

            ServiceInfo serviceInfo = info.getResolveInfo().serviceInfo;
            ComponentName componentName = new ComponentName(serviceInfo.packageName,
                    serviceInfo.name);

            preference.setKey(componentName.flattenToString());

            preference.setTitle(title);
            final boolean serviceEnabled = accessibilityEnabled
                    && enabledServices.contains(componentName);
            String serviceEnabledString;
            if (serviceEnabled) {
                serviceEnabledString = getString(R.string.accessibility_feature_state_on);
            } else {
                serviceEnabledString = getString(R.string.accessibility_feature_state_off);
            }

            // Disable all accessibility services that are not permitted.
            String packageName = serviceInfo.packageName;
            boolean serviceAllowed =
                    permittedServices == null || permittedServices.contains(packageName);
            if (!serviceAllowed && !serviceEnabled) {
                EnforcedAdmin admin = RestrictedLockUtils.checkIfAccessibilityServiceDisallowed(
                        getActivity(), serviceInfo.packageName, UserHandle.myUserId());
                if (admin != null) {
                    preference.setDisabledByAdmin(admin);
                } else {
                    preference.setEnabled(false);
                }
            } else {
                preference.setEnabled(true);
            }

            preference.setSummary(serviceEnabledString);

            preference.setOrder(i);
            preference.setFragment(ToggleAccessibilityServicePreferenceFragment.class.getName());
            preference.setPersistent(true);

            Bundle extras = preference.getExtras();
            extras.putString(EXTRA_PREFERENCE_KEY, preference.getKey());
            extras.putBoolean(EXTRA_CHECKED, serviceEnabled);
            extras.putString(EXTRA_TITLE, title);

            String description = info.loadDescription(getPackageManager());
            if (TextUtils.isEmpty(description)) {
                description = getString(R.string.accessibility_service_default_description);
            }
            extras.putString(EXTRA_SUMMARY, description);

            String settingsClassName = info.getSettingsActivityName();
            if (!TextUtils.isEmpty(settingsClassName)) {
                extras.putString(EXTRA_SETTINGS_TITLE,
                        getString(R.string.accessibility_menu_item_settings));
                extras.putString(EXTRA_SETTINGS_COMPONENT_NAME,
                        new ComponentName(info.getResolveInfo().serviceInfo.packageName,
                                settingsClassName).flattenToString());
            }

            extras.putParcelable(EXTRA_COMPONENT_NAME, componentName);

            mServicesCategory.addPreference(preference);
        }

3.微信抢红包-案例

简书的这位大神写的很好哦，妙赞

https://www.jianshu.com/p/4cd8c109cdfb