橋接模式（Bridge Pattern）定義和使用場(chǎng)景
- 定義
橋接模式(Bridge Pattern)：將抽象部分與它的實(shí)現(xiàn)部分分離，使它們都可以獨(dú)立地變化。它是一種對(duì)象結(jié)構(gòu)型模式，又稱為柄體(Handle and Body)模式或接口(Interface)模式。
實(shí)現(xiàn)系統(tǒng)可能有多個(gè)角度分類，每一種角度都可能變化，那么把這種多角度分類給分離出來(lái)讓他們獨(dú)立變化，減少他們之間耦合。
- 使用場(chǎng)景
如果一個(gè)系統(tǒng)需要在構(gòu)件的抽象化和具體角色之間增加更多的靈活性，避免在兩個(gè)層次之間建立靜態(tài)的繼承聯(lián)系，可以通過(guò)橋接模式使它們?cè)诔橄髮咏⒁粋€(gè)關(guān)聯(lián)關(guān)系。對(duì)于那些不希望使用繼承或因?yàn)槎鄬哟卫^承導(dǎo)致系統(tǒng)類的個(gè)數(shù)急劇增加的系統(tǒng)，橋接模式尤為適用。一個(gè)類存在兩個(gè)獨(dú)立變化的維度，且這兩個(gè)維度都需要進(jìn)行擴(kuò)展。 -
橋接模式的UML類圖
橋接模式
Abstraction：抽象部分。該類保持一個(gè)對(duì)實(shí)現(xiàn)部分的引用，抽象部分中的方法需要調(diào)用實(shí)現(xiàn)部分的對(duì)象來(lái)實(shí)現(xiàn)，該類一般為抽象類。
RefinedAbstraction：優(yōu)化的抽象部分。抽象部分的具體實(shí)現(xiàn)，該類一般是對(duì)抽象部分的方法進(jìn)行完善和擴(kuò)展。
Implementor：實(shí)現(xiàn)部分?？梢詾榻涌诨蛘叱橄箢?，其方法不一定要與抽象部分中的一致，一般情況下是由實(shí)現(xiàn)部分提供基本的操作，而抽象部分定義的則是基于實(shí)現(xiàn)部分這些基本操作的業(yè)務(wù)方法。
ConcreteImplementorA/ConcreteImplementorB：實(shí)現(xiàn)部分的具體實(shí)現(xiàn)。完善實(shí)現(xiàn)部分中方法定義的具體邏輯。
Client：客戶類，客戶端程序。 - 生活實(shí)例闡述
- 開關(guān)與具體的電器，開關(guān)的類型有很多，也是有各種各樣的，這兩者是獨(dú)立的且又有耦合。
- 電腦的主機(jī)箱和電腦廠商，主機(jī)箱的樣式是有多種多樣的而電腦的廠商也是有很多，所以這也可以是一種橋接模式。
3.Java語(yǔ)言通過(guò)Java虛擬機(jī)實(shí)現(xiàn)了平臺(tái)的無(wú)關(guān)性，Java語(yǔ)言的程序和運(yùn)行Java成語(yǔ)的平臺(tái)的，這也是橋接模式的一種實(shí)現(xiàn)。
橋接模式的簡(jiǎn)單代碼實(shí)例
用不同顏色的筆畫出不同形狀的圖形，畫筆的顏色可以是有多種多樣的，畫的圖形也可以是有正方形、長(zhǎng)方形等不同的圖形。
public interface Paint {
void userPaintColor();
}
public class RedPaint implements Paint{
@Override
public void userPaintColor() {
System.out.println("用紅色的筆去畫");
}
}
public class BluePaint implements Paint{
@Override
public void userPaintColor() {
System.out.println("用藍(lán)色的筆去畫");
}
}
public abstract class DrawShape {
protected Paint paintImple;
public DrawShape(Paint paintImple){
this.paintImple=paintImple;
}
public abstract void drawShape();
}
public class CircleShape extends DrawShape{
public CircleShape(Paint paintImple) {
super(paintImple);
}
@Override
public void drawShape() {
paintImple.userPaintColor();
System.out.println("畫出圓形");
}
}
public class SquareShape extends DrawShape{
public SquareShape(Paint paintImple) {
super(paintImple);
}
@Override
public void drawShape() {
paintImple.userPaintColor();
System.out.println("畫出正方形");
}
}
public class TestDemo {
public static void main(String a[])
{
CircleShape circleShape=new CircleShape(new RedPaint());
circleShape.drawShape();
SquareShape squareShape=new SquareShape(new RedPaint());
squareShape.drawShape();
}
}
打印結(jié)果
image.png
Android源碼中的橋接模式實(shí)現(xiàn)
在View的視圖層中，CheckBox、CompoundButton、Button、TextView和View之間構(gòu)成一個(gè)繼承關(guān)系的視圖層級(jí)，每一層級(jí)都僅僅是對(duì)一個(gè)類型控件的描述，定義了該類控件所擁有的基本屬性和行為，但是將它們真正繪制到屏幕的部分是由與View相關(guān)的功能實(shí)現(xiàn)類DisplayList、HardwareLayer和Canvas負(fù)責(zé)。
-
另外一個(gè)比較典型Window與WindowManager之間的關(guān)系，Window和PhoneWindow構(gòu)成窗口的抽象部分，其中Window類為該抽象部分的抽象接口，PhoneWindow為抽象部分具體的實(shí)現(xiàn)及擴(kuò)展。WindowsManager則為實(shí)現(xiàn)部分的基類，WindowManagerImpl為實(shí)現(xiàn)部分具體的實(shí)現(xiàn)及擴(kuò)展，其使用WindowManagerGlobal通過(guò)IWindowManager接口與WindowManagerService進(jìn)行交互，并由WMS完成具體的窗口管理工具。
image1.png
WindowManagerServer
在Android的framework層主要就是由WindowManagerServer與另外一個(gè)系統(tǒng)服務(wù)ActivityManagerService還有View所構(gòu)成。
WindowManagerService在SystemServer中的main方法中啟動(dòng)
public static void main(String[] args) {
new SystemServer().run();
}
public SystemServer() {
// Check for factory test mode.
mFactoryTestMode = FactoryTest.getMode();
}
private void run() {
try {
Trace.traceBegin(Trace.TRACE_TAG_SYSTEM_SERVER, "InitBeforeStartServices");
// If a device's clock is before 1970 (before 0), a lot of
// APIs crash dealing with negative numbers, notably
// java.io.File#setLastModified, so instead we fake it and
// hope that time from cell towers or NTP fixes it shortly.
if (System.currentTimeMillis() < EARLIEST_SUPPORTED_TIME) {
Slog.w(TAG, "System clock is before 1970; setting to 1970.");
SystemClock.setCurrentTimeMillis(EARLIEST_SUPPORTED_TIME);
}
// If the system has "persist.sys.language" and friends set, replace them with
// "persist.sys.locale". Note that the default locale at this point is calculated
// using the "-Duser.locale" command line flag. That flag is usually populated by
// AndroidRuntime using the same set of system properties, but only the system_server
// and system apps are allowed to set them.
//
// NOTE: Most changes made here will need an equivalent change to
// core/jni/AndroidRuntime.cpp
if (!SystemProperties.get("persist.sys.language").isEmpty()) {
final String languageTag = Locale.getDefault().toLanguageTag();
SystemProperties.set("persist.sys.locale", languageTag);
SystemProperties.set("persist.sys.language", "");
SystemProperties.set("persist.sys.country", "");
SystemProperties.set("persist.sys.localevar", "");
}
// Here we go!
Slog.i(TAG, "Entered the Android system server!");
EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_SYSTEM_RUN, SystemClock.uptimeMillis());
// In case the runtime switched since last boot (such as when
// the old runtime was removed in an OTA), set the system
// property so that it is in sync. We can't do this in
// libnativehelper's JniInvocation::Init code where we already
// had to fallback to a different runtime because it is
// running as root and we need to be the system user to set
// the property. http://b/11463182
SystemProperties.set("persist.sys.dalvik.vm.lib.2", VMRuntime.getRuntime().vmLibrary());
// Enable the sampling profiler.
if (SamplingProfilerIntegration.isEnabled()) {
SamplingProfilerIntegration.start();
mProfilerSnapshotTimer = new Timer();
mProfilerSnapshotTimer.schedule(new TimerTask() {
@Override
public void run() {
SamplingProfilerIntegration.writeSnapshot("system_server", null);
}
}, SNAPSHOT_INTERVAL, SNAPSHOT_INTERVAL);
}
// Mmmmmm... more memory!
VMRuntime.getRuntime().clearGrowthLimit();
// The system server has to run all of the time, so it needs to be
// as efficient as possible with its memory usage.
VMRuntime.getRuntime().setTargetHeapUtilization(0.8f);
// Some devices rely on runtime fingerprint generation, so make sure
// we've defined it before booting further.
Build.ensureFingerprintProperty();
// Within the system server, it is an error to access Environment paths without
// explicitly specifying a user.
Environment.setUserRequired(true);
// Within the system server, any incoming Bundles should be defused
// to avoid throwing BadParcelableException.
BaseBundle.setShouldDefuse(true);
// Ensure binder calls into the system always run at foreground priority.
BinderInternal.disableBackgroundScheduling(true);
// Increase the number of binder threads in system_server
BinderInternal.setMaxThreads(sMaxBinderThreads);
// Prepare the main looper thread (this thread).
android.os.Process.setThreadPriority(
android.os.Process.THREAD_PRIORITY_FOREGROUND);
android.os.Process.setCanSelfBackground(false);
Looper.prepareMainLooper();
// Initialize native services.
System.loadLibrary("android_servers");
// Check whether we failed to shut down last time we tried.
// This call may not return.
performPendingShutdown();
// Initialize the system context.
createSystemContext();
// Create the system service manager.
mSystemServiceManager = new SystemServiceManager(mSystemContext);
LocalServices.addService(SystemServiceManager.class, mSystemServiceManager);
} finally {
Trace.traceEnd(Trace.TRACE_TAG_SYSTEM_SERVER);
}
// Start services.
try {
Trace.traceBegin(Trace.TRACE_TAG_SYSTEM_SERVER, "StartServices");
// 安裝應(yīng)用需要的
startBootstrapServices();
startCoreServices();
// 啟動(dòng)服務(wù)
startOtherServices();
} catch (Throwable ex) {
Slog.e("System", "******************************************");
Slog.e("System", "************ Failure starting system services", ex);
throw ex;
} finally {
Trace.traceEnd(Trace.TRACE_TAG_SYSTEM_SERVER);
}
// For debug builds, log event loop stalls to dropbox for analysis.
if (StrictMode.conditionallyEnableDebugLogging()) {
Slog.i(TAG, "Enabled StrictMode for system server main thread.");
}
// Loop forever.
Looper.loop();
throw new RuntimeException("Main thread loop unexpectedly exited");
}
private void startOtherServices() {
final Context context = mSystemContext;
VibratorService vibrator = null;
IMountService mountService = null;
NetworkManagementService networkManagement = null;
NetworkStatsService networkStats = null;
NetworkPolicyManagerService networkPolicy = null;
ConnectivityService connectivity = null;
NetworkScoreService networkScore = null;
NsdService serviceDiscovery= null;
WindowManagerService wm = null;
SerialService serial = null;
NetworkTimeUpdateService networkTimeUpdater = null;
CommonTimeManagementService commonTimeMgmtService = null;
InputManagerService inputManager = null;
TelephonyRegistry telephonyRegistry = null;
ConsumerIrService consumerIr = null;
MmsServiceBroker mmsService = null;
HardwarePropertiesManagerService hardwarePropertiesService = null;
boolean disableStorage = SystemProperties.getBoolean("config.disable_storage", false);
boolean disableBluetooth = SystemProperties.getBoolean("config.disable_bluetooth", false);
boolean disableLocation = SystemProperties.getBoolean("config.disable_location", false);
boolean disableSystemUI = SystemProperties.getBoolean("config.disable_systemui", false);
boolean disableNonCoreServices = SystemProperties.getBoolean("config.disable_noncore", false);
boolean disableNetwork = SystemProperties.getBoolean("config.disable_network", false);
boolean disableNetworkTime = SystemProperties.getBoolean("config.disable_networktime", false);
boolean disableRtt = SystemProperties.getBoolean("config.disable_rtt", false);
boolean disableMediaProjection = SystemProperties.getBoolean("config.disable_mediaproj",
false);
boolean disableSerial = SystemProperties.getBoolean("config.disable_serial", false);
boolean disableSearchManager = SystemProperties.getBoolean("config.disable_searchmanager",
false);
boolean disableTrustManager = SystemProperties.getBoolean("config.disable_trustmanager",
false);
boolean disableTextServices = SystemProperties.getBoolean("config.disable_textservices", false);
boolean disableSamplingProfiler = SystemProperties.getBoolean("config.disable_samplingprof",
false);
boolean isEmulator = SystemProperties.get("ro.kernel.qemu").equals("1");
try {
Slog.i(TAG, "Reading configuration...");
SystemConfig.getInstance();
traceBeginAndSlog("StartSchedulingPolicyService");
ServiceManager.addService("scheduling_policy", new SchedulingPolicyService());
Trace.traceEnd(Trace.TRACE_TAG_SYSTEM_SERVER);
mSystemServiceManager.startService(TelecomLoaderService.class);
traceBeginAndSlog("StartTelephonyRegistry");
telephonyRegistry = new TelephonyRegistry(context);
ServiceManager.addService("telephony.registry", telephonyRegistry);
Trace.traceEnd(Trace.TRACE_TAG_SYSTEM_SERVER);
traceBeginAndSlog("StartEntropyMixer");
mEntropyMixer = new EntropyMixer(context);
Trace.traceEnd(Trace.TRACE_TAG_SYSTEM_SERVER);
mContentResolver = context.getContentResolver();
Slog.i(TAG, "Camera Service");
mSystemServiceManager.startService(CameraService.class);
// The AccountManager must come before the ContentService
traceBeginAndSlog("StartAccountManagerService");
mSystemServiceManager.startService(ACCOUNT_SERVICE_CLASS);
Trace.traceEnd(Trace.TRACE_TAG_SYSTEM_SERVER);
traceBeginAndSlog("StartContentService");
mSystemServiceManager.startService(CONTENT_SERVICE_CLASS);
Trace.traceEnd(Trace.TRACE_TAG_SYSTEM_SERVER);
traceBeginAndSlog("InstallSystemProviders");
mActivityManagerService.installSystemProviders();
Trace.traceEnd(Trace.TRACE_TAG_SYSTEM_SERVER);
traceBeginAndSlog("StartVibratorService");
vibrator = new VibratorService(context);
ServiceManager.addService("vibrator", vibrator);
Trace.traceEnd(Trace.TRACE_TAG_SYSTEM_SERVER);
traceBeginAndSlog("StartConsumerIrService");
consumerIr = new ConsumerIrService(context);
ServiceManager.addService(Context.CONSUMER_IR_SERVICE, consumerIr);
Trace.traceEnd(Trace.TRACE_TAG_SYSTEM_SERVER);
traceBeginAndSlog("StartAlarmManagerService");
mSystemServiceManager.startService(AlarmManagerService.class);
Trace.traceEnd(Trace.TRACE_TAG_SYSTEM_SERVER);
traceBeginAndSlog("InitWatchdog");
final Watchdog watchdog = Watchdog.getInstance();
watchdog.init(context, mActivityManagerService);
Trace.traceEnd(Trace.TRACE_TAG_SYSTEM_SERVER);
traceBeginAndSlog("StartInputManagerService");
inputManager = new InputManagerService(context);
Trace.traceEnd(Trace.TRACE_TAG_SYSTEM_SERVER);
traceBeginAndSlog("StartWindowManagerService");
wm = WindowManagerService.main(context, inputManager,
mFactoryTestMode != FactoryTest.FACTORY_TEST_LOW_LEVEL,
!mFirstBoot, mOnlyCore);
ServiceManager.addService(Context.WINDOW_SERVICE, wm);
ServiceManager.addService(Context.INPUT_SERVICE, inputManager);
Trace.traceEnd(Trace.TRACE_TAG_SYSTEM_SERVER);
traceBeginAndSlog("StartVrManagerService");
mSystemServiceManager.startService(VrManagerService.class);
Trace.traceEnd(Trace.TRACE_TAG_SYSTEM_SERVER);
mActivityManagerService.setWindowManager(wm);
inputManager.setWindowManagerCallbacks(wm.getInputMonitor());
inputManager.start();
// TODO: Use service dependencies instead.
mDisplayManagerService.windowManagerAndInputReady();
// Skip Bluetooth if we have an emulator kernel
// TODO: Use a more reliable check to see if this product should
// support Bluetooth - see bug 988521
if (isEmulator) {
Slog.i(TAG, "No Bluetooth Service (emulator)");
} else if (mFactoryTestMode == FactoryTest.FACTORY_TEST_LOW_LEVEL) {
Slog.i(TAG, "No Bluetooth Service (factory test)");
} else if (!context.getPackageManager().hasSystemFeature
(PackageManager.FEATURE_BLUETOOTH)) {
Slog.i(TAG, "No Bluetooth Service (Bluetooth Hardware Not Present)");
} else if (disableBluetooth) {
Slog.i(TAG, "Bluetooth Service disabled by config");
} else {
mSystemServiceManager.startService(BluetoothService.class);
}
traceBeginAndSlog("ConnectivityMetricsLoggerService");
mSystemServiceManager.startService(MetricsLoggerService.class);
Trace.traceEnd(Trace.TRACE_TAG_SYSTEM_SERVER);
traceBeginAndSlog("IpConnectivityMetrics");
mSystemServiceManager.startService(IpConnectivityMetrics.class);
Trace.traceEnd(Trace.TRACE_TAG_SYSTEM_SERVER);
traceBeginAndSlog("PinnerService");
mSystemServiceManager.startService(PinnerService.class);
Trace.traceEnd(Trace.TRACE_TAG_SYSTEM_SERVER);
} catch (RuntimeException e) {
Slog.e("System", "******************************************");
Slog.e("System", "************ Failure starting core service", e);
}
.....
省略其他代碼
通過(guò)這個(gè)方法獲取WindowmanagerService的實(shí)例，并且把他加到ServiceMange里面，然后其他進(jìn)程都可以通過(guò)ServiceManager查詢獲取到WindowsManagerService。
wm = WindowManagerService.main(context, inputManager,
mFactoryTestMode != FactoryTest.FACTORY_TEST_LOW_LEVEL,
!mFirstBoot, mOnlyCore);
ServiceManager.addService(Context.WINDOW_SERVICE, wm);
WindowsManagerService的mian方法
private WindowManagerService(Context context, InputManagerService inputManager,
boolean haveInputMethods, boolean showBootMsgs, boolean onlyCore) {
mContext = context;
mHaveInputMethods = haveInputMethods;
mAllowBootMessages = showBootMsgs;
mOnlyCore = onlyCore;
mLimitedAlphaCompositing = context.getResources().getBoolean(
com.android.internal.R.bool.config_sf_limitedAlpha);
mHasPermanentDpad = context.getResources().getBoolean(
com.android.internal.R.bool.config_hasPermanentDpad);
mInTouchMode = context.getResources().getBoolean(
com.android.internal.R.bool.config_defaultInTouchMode);
mDrawLockTimeoutMillis = context.getResources().getInteger(
com.android.internal.R.integer.config_drawLockTimeoutMillis);
mAllowAnimationsInLowPowerMode = context.getResources().getBoolean(
com.android.internal.R.bool.config_allowAnimationsInLowPowerMode);
mInputManager = inputManager; // Must be before createDisplayContentLocked.
mDisplayManagerInternal = LocalServices.getService(DisplayManagerInternal.class);
mDisplaySettings = new DisplaySettings();
mDisplaySettings.readSettingsLocked();
mWallpaperControllerLocked = new WallpaperController(this);
mWindowPlacerLocked = new WindowSurfacePlacer(this);
mLayersController = new WindowLayersController(this);
LocalServices.addService(WindowManagerPolicy.class, mPolicy);
mPointerEventDispatcher = new PointerEventDispatcher(mInputManager.monitorInput(TAG_WM));
mFxSession = new SurfaceSession();
mDisplayManager = (DisplayManager)context.getSystemService(Context.DISPLAY_SERVICE);
mDisplays = mDisplayManager.getDisplays();
for (Display display : mDisplays) {
createDisplayContentLocked(display);
}
mKeyguardDisableHandler = new KeyguardDisableHandler(mContext, mPolicy);
mPowerManager = (PowerManager)context.getSystemService(Context.POWER_SERVICE);
mPowerManagerInternal = LocalServices.getService(PowerManagerInternal.class);
mPowerManagerInternal.registerLowPowerModeObserver(
new PowerManagerInternal.LowPowerModeListener() {
@Override
public void onLowPowerModeChanged(boolean enabled) {
synchronized (mWindowMap) {
if (mAnimationsDisabled != enabled && !mAllowAnimationsInLowPowerMode) {
mAnimationsDisabled = enabled;
dispatchNewAnimatorScaleLocked(null);
}
}
}
});
mAnimationsDisabled = mPowerManagerInternal.getLowPowerModeEnabled();
mScreenFrozenLock = mPowerManager.newWakeLock(
PowerManager.PARTIAL_WAKE_LOCK, "SCREEN_FROZEN");
mScreenFrozenLock.setReferenceCounted(false);
mAppTransition = new AppTransition(context, this);
mAppTransition.registerListenerLocked(mActivityManagerAppTransitionNotifier);
mBoundsAnimationController =
new BoundsAnimationController(mAppTransition, UiThread.getHandler());
mActivityManager = ActivityManagerNative.getDefault();
mAmInternal = LocalServices.getService(ActivityManagerInternal.class);
mAppOps = (AppOpsManager)context.getSystemService(Context.APP_OPS_SERVICE);
AppOpsManager.OnOpChangedInternalListener opListener =
new AppOpsManager.OnOpChangedInternalListener() {
@Override public void onOpChanged(int op, String packageName) {
updateAppOpsState();
}
};
mAppOps.startWatchingMode(AppOpsManager.OP_SYSTEM_ALERT_WINDOW, null, opListener);
mAppOps.startWatchingMode(AppOpsManager.OP_TOAST_WINDOW, null, opListener);
// Get persisted window scale setting
mWindowAnimationScaleSetting = Settings.Global.getFloat(context.getContentResolver(),
Settings.Global.WINDOW_ANIMATION_SCALE, mWindowAnimationScaleSetting);
mTransitionAnimationScaleSetting = Settings.Global.getFloat(context.getContentResolver(),
Settings.Global.TRANSITION_ANIMATION_SCALE, mTransitionAnimationScaleSetting);
setAnimatorDurationScale(Settings.Global.getFloat(context.getContentResolver(),
Settings.Global.ANIMATOR_DURATION_SCALE, mAnimatorDurationScaleSetting));
// Track changes to DevicePolicyManager state so we can enable/disable keyguard.
IntentFilter filter = new IntentFilter();
filter.addAction(DevicePolicyManager.ACTION_DEVICE_POLICY_MANAGER_STATE_CHANGED);
mContext.registerReceiver(mBroadcastReceiver, filter);
mSettingsObserver = new SettingsObserver();
mHoldingScreenWakeLock = mPowerManager.newWakeLock(
PowerManager.SCREEN_BRIGHT_WAKE_LOCK | PowerManager.ON_AFTER_RELEASE, TAG_WM);
mHoldingScreenWakeLock.setReferenceCounted(false);
mAnimator = new WindowAnimator(this);
mAllowTheaterModeWakeFromLayout = context.getResources().getBoolean(
com.android.internal.R.bool.config_allowTheaterModeWakeFromWindowLayout);
LocalServices.addService(WindowManagerInternal.class, new LocalService());
initPolicy();
// Add ourself to the Watchdog monitors.
Watchdog.getInstance().addMonitor(this);
SurfaceControl.openTransaction();
try {
createWatermarkInTransaction();
} finally {
SurfaceControl.closeTransaction();
}
showEmulatorDisplayOverlayIfNeeded();
}
public static WindowManagerService main(final Context context,
final InputManagerService im,
final boolean haveInputMethods, final boolean showBootMsgs,
final boolean onlyCore) {
final WindowManagerService[] holder = new WindowManagerService[1];
DisplayThread.getHandler().runWithScissors(new Runnable() {
@Override
public void run() {
holder[0] = new WindowManagerService(context, im,
haveInputMethods, showBootMsgs, onlyCore);
}
}, 0);
return holder[0];
}
橋接模式的優(yōu)點(diǎn)
- 橋接模式實(shí)現(xiàn)了抽象化與實(shí)現(xiàn)化的脫耦。他們兩個(gè)互相獨(dú)立，不會(huì)影響到對(duì)方。
- 對(duì)于兩個(gè)獨(dú)立變化的維度，使用橋接模式再適合不過(guò)了。
- 對(duì)于“具體的抽象類”所做的改變，是不會(huì)影響到客戶。
