一分钟实现 Android textview 跑马灯文字滚动效果

*文字水平跑马灯效果：

设置如下TextView控件文件的XML：

<com.example.Mytext
        android:id="@+id/textview" 
        android:layout_width="match_parent"
        android:layout_height="20dp"
        android:gravity="center"
        android:singleLine="true"//限制行数为1行
        android:ellipsize="marquee"//marquee 文字滚动
        android:marqueeRepeatLimit="marquee_forever"//文字滚动次数：marquee_forever 无限次
        android:focusable="true"//获取焦点
        android:focusableInTouchMode="true"//获取触摸焦点
        android:textColor="@color/red"
        android:text="@string/text"
         />

有其它布局如ScrollView等抢占焦点，需要自定义控件获取焦点：

public class Mytext extends TextView {  
public Mytext(Context context, AttributeSet attrs) {  
super(context, attrs);  
    } 
@Override
protected void onFocusChanged(boolean focused, int direction,
Rect previouslyFocusedRect) {
if(focused){  
super.onFocusChanged(focused, direction, previouslyFocusedRect);
     }
}
@Override  
public void onWindowFocusChanged(boolean hasWindowFocus) {  
if(hasWindowFocus){  
super.onWindowFocusChanged(hasWindowFocus); 
     } 
}  
@Override  
public boolean isFocused() {  
return true;  
     }  
}

*文字切换动画效果：

 1 public class MainActivity extends Activity {
 2     private static final String[] TEXTS = { "First", "Second", "Third" };
 3     private int mTextsPosition = 0;
 4     private TextSwitcher mTextSwitcher;
 5     @Override
 6     public void onCreate(Bundle savedInstanceState) {
 7         super.onCreate(savedInstanceState);
 8         setContentView(R.layout.main);
 9         mTextSwitcher = (TextSwitcher) findViewById(R.id.your_textview);
10         mTextSwitcher.setFactory(new ViewFactory() {
11             @Override
12             public View makeView() {
13                 System.out.println("makeView");
14                 TextView t = new TextView(MainActivity.this);
15                 t.setGravity(Gravity.CENTER);//t.setTextColor(Color.BLACK);
16                 return t;
17             }
18         });
19         mTextSwitcher.setInAnimation(this, android.R.anim.fade_in);
20         mTextSwitcher.setOutAnimation(this, android.R.anim.fade_out);
21         onSwitchText(null);
22     }
23     public void onSwitchText(View v) {
24         mTextSwitcher.setText(TEXTS[mTextsPosition]);
25         setNextPosition();
26     }
27     private void setNextPosition() {
28         mTextsPosition = (mTextsPosition + 1) % TEXTS.length;
29     }
30 }