Android学习（二） 标签滚动跳过

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <com.example.marqueetextview.MarqueeText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:singleLine="true"
        android:ellipsize="marquee"
        android:focusable="true"
        android:focusableInTouchMode="true"
        android:text="@string/hello_world" />
    
    <com.example.marqueetextview.MarqueeText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:singleLine="true"
        android:ellipsize="marquee"
        android:focusable="true"
        android:focusableInTouchMode="true"
        android:text="@string/hello_world" />

</RelativeLayout>

后台实现：

public class MarqueeText extends TextView{

    public MarqueeText(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        // TODO Auto-generated constructor stub
    }

    public MarqueeText(Context context, AttributeSet attrs) {
        super(context, attrs);
        // TODO Auto-generated constructor stub
    }

    public MarqueeText(Context context) {
        super(context);
        // TODO Auto-generated constructor stub
    }
    
    @Override
    @ExportedProperty(category = "focus")
    public boolean isFocused() {
        //继承TextView类，重写isFocused方法，返回true，因为marquee只有在当前控件获取焦点时才会滚动。
        return true;
    }

}