1.修改以下三个文件中home和recent_app的visibility属性为gone：

frameworks/base/packages/SystemUI/res/layout-ldrtl/navigation_bar.xml

frameworks/base/packages/SystemUI/res/layout-sw600dp/navigation_bar.xml

frameworks/base/packages/SystemUI/res/layout/navigation_bar.xml

--- a/frameworks/base/packages/SystemUI/res/layout-ldrtl/navigation_bar.xml

+++ b/frameworks/base/packages/SystemUI/res/layout-ldrtl/navigation_bar.xml

@@ -70,6 +70,7 @@

systemui:keyCode="3"

systemui:keyRepeat="true"

android:layout_weight="0"

+ android:visibility="gone"

systemui:glowBackground="@drawable/ic_sysbar_highlight"

android:contentDescription="@string/accessibility_home"

/>

@@ -78,6 +79,7 @@

android:layout_height="match_parent"

android:src="@drawable/ic_sysbar_recent"

android:layout_weight="0"

+ android:visibility="gone"

systemui:glowBackground="@drawable/ic_sysbar_highlight"

android:contentDescription="@string/accessibility_recent"

/>

@@ -236,6 +238,7 @@

systemui:keyCode="3"

systemui:keyRepeat="true"

android:layout_weight="0"

+ android:visibility="gone"

systemui:glowBackground="@drawable/ic_sysbar_highlight"

android:contentDescription="@string/accessibility_home"

/>

@@ -244,6 +247,7 @@

android:layout_height="match_parent"

android:src="@drawable/ic_sysbar_recent"

android:layout_weight="0"

+ android:visibility="gone"

systemui:glowBackground="@drawable/ic_sysbar_highlight"

android:contentDescription="@string/accessibility_recent"

/>

2.NavigationBarView在代码中将Home和RecentApp可见性设为GONE：

frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/phone/NavigationBarView.java

--- a/frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/phone/NavigationBarView.java

+++ b/frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/phone/NavigationBarView.java

@@ -484,6 +484,8 @@ public class NavigationBarView extends LinearLayout {

getBackButton() .setVisibility(disableBack ? View.INVISIBLE : View.VISIBLE);

getHomeButton() .setVisibility(disableHome ? View.INVISIBLE : View.VISIBLE);

getRecentsButton().setVisibility(disableRecent ? View.INVISIBLE : View.VISIBLE);

+ getHomeButton().setVisibility(View.GONE);

+ getRecentsButton().setVisibility(View.GONE);

/// M: add for multi window @{

if(RecentsActivity.FLOAT_WINDOW_SUPPORT){

diff --git a/frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java b/frameworks/base/packages

index 6ac08b4..23d4ad0 100644

--- a/frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java

+++ b/frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java

@@ -1283,6 +1283,8 @@ private boolean musbmounted = false;

mNavigationBarView.getFloatButton().setOnClickListener(mFloatClickListener);

}

/// @}

+ mNavigationBarView.getHomeButton().setVisibility(View.GONE);

+ mNavigationBarView.getRecentsButton().setVisibility(View.GONE);

updateSearchPanel();

} 这样导航栏就只剩下返回键了。