跑马灯

< TextView  android:layout_width ="100px"
        android:layout_height ="wrap_content"
        android:textColor ="@android:color/white"  
        android:ellipsize ="marquee"  
        android:focusable ="true"  
        android:marqueeRepeatLimit ="marquee_forever"  
        android:focusableInTouchMode ="true"  
        android:scrollHorizontally ="true"
        android:text ="这才是真正的文字跑马灯效果"
         >
     </ TextView >