Android TabHost选项卡标签图标始终不出现的解决方法

TapSpec spec1 = tabHost.newTabSpec("tab 1");
spec1.setIndicator("选项卡一", getResources().getDrawable(R.drawable.tab_icon));
spec1.setContent(R.id.tab1);
tabHost.addTab(spec1);

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="0dip"
android:layout_height="64dip"
android:layout_weight="1"
android:orientation="vertical"
android:background="@drawable/tab_indicator"
android:padding="5dp">
<ImageView android:id="@+id/icon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
/>
<TextView android:id="@+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
style="?android:attr/tabWidgetStyle"
/>
</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="@drawable/tab_info_dark"
android:state_selected="true" />
<item android:drawable="@drawable/tab_info_light" />
</selector>

private void addTab(String label, int drawableId) {
Intent intent = new Intent(this, MockActivity.class);
TabHost.TabSpec spec = tabHost.newTabSpec(label);
View tabIndicator = LayoutInflater.from(this).inflate(R.layout.tab_indicator, getTabWidget(), false);
TextView title = (TextView) tabIndicator.findViewById(R.id.title);
title.setText(label);
ImageView icon = (ImageView) tabIndicator.findViewById(R.id.icon);
icon.setImageResource(drawableId);
spec.setIndicator(tabIndicator);
spec.setContent(intent);
tabHost.addTab(spec);
}

tabHost = getTabHost(); //tabHost is a private field
addTab("First", R.drawable.tab_info);
addTab("Second", R.drawable.tab_info);
addTab("Third", R.drawable.tab_info);