我们想要在volume、back、menu同一排添加一个虚拟按键，并且触发一个应用；

1、首先我们要找到这些虚拟按键的位置：\frameworks\base\packages\SystemUI\res\layout-sw600dp\navigation_bar.xml

2、横屏时，最左边的RelativeLayout 中添加：

......

android:layout_height="match_parent"

android:layout_width="match_parent"

>

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_gravity="left">

android:id="@+id/img_logo"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_gravity="left|center_vertical"

android:paddingLeft="5.0dip"

android:src="@drawable/img_logo"

systemui:glowBackground="@drawable/ic_sysbar_highlight"

android:contentDescription="@string/accessibility_recent"/>

......

竖屏时，最左边的RelativeLayout 中添加：

......

android:layout_height="match_parent"

android:layout_width="match_parent"

android:visibility="gone"

android:paddingTop="0dp"

>

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_gravity="left">

android:id="@+id/img_logo"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_gravity="left|center_vertical"

android:paddingLeft="5.0dip"

android:src="@drawable/img_logo"

systemui:glowBackground="@drawable/ic_sysbar_highlight"

android:contentDescription="@string/accessibility_recent"/>

......

3、添加java触发代码：\frameworks\base\packages\SystemUI\src\com\android\systemui\statusbar\phone\NavigationBarView.java

(1)  ......

import android.content.ComponentName;//add Await

(2) //add Await 返回图标

public View getImgLogo(){

return mCurrentView.findViewById(R.id.img_logo);

}

(3)添加触发应用：

public void setNavigationIconHints(int hints, boolean force) {

if (!force && hints == mNavigationIconHints) return;

final boolean backAlt = (hints & StatusBarManager.NAVIGATION_HINT_BACK_ALT) != 0;

if ((mNavigationIconHints & StatusBarManager.NAVIGATION_HINT_BACK_ALT) != 0 && !backAlt) {

mTransitionListener.onBackAltCleared();

}

if (DEBUG) {

android.widget.Toast.makeText(mContext,

"Navigation icon hints = " + hints,

500).show();

}

mNavigationIconHints = hints;

((ImageView)getBackButton()).setImageDrawable(backAlt

? (mVertical ? mBackAltLandIcon : mBackAltIcon)

: (mVertical ? mBackLandIcon : mBackIcon));

((ImageView)getRecentsButton()).setImageDrawable(mVertical ? mRecentLandIcon : mRecentIcon);

//add Await

((ImageView)getImgLogo()).setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

Intent mIntent = new Intent( );

mIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

ComponentName comp = new ComponentName("com.xintu.navcity", "com.xintu.navcity.MainActivity");

mIntent.setComponent(comp);

mIntent.setAction("android.intent.action.VIEW");

mContext.startActivity(mIntent);

}

});

setDisabledFlags(mDisabledFlags, true);

}