Android跑马灯效果可控制的代码实现

public class MarqueeText extends TextView implements Runnable {
private int currentScrollX;// 当前滚动的位置
private boolean isStop = false;
private int textWidth;
private boolean isMeasure = false;
public MarqueeText(Context context) {
super(context);
// TODO Auto-generated constructor stub
}
public MarqueeText(Context context, AttributeSet attrs) {
super(context, attrs);
}
public MarqueeText(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
super.onDraw(canvas);
if (!isMeasure) {// 文字宽度只需获取一次就可以了
getTextWidth();
isMeasure = true;
}
}
/**
* 获取文字宽度
*/
private void getTextWidth() {
Paint paint = this.getPaint();
String str = this.getText().toString();
textWidth = (int) paint.measureText(str);
}
@Override
public void run() {
currentScrollX -= 2;// 滚动速度
scrollTo(currentScrollX, 0);
if (isStop) {
return;
}
if (getScrollX() scrollTo(textWidth, 0);
currentScrollX = textWidth;
// return;
}
postDelayed(this, 5);
}
// 开始滚动
public void startScroll() {
isStop = false;
this.removeCallbacks(this);
post(this);
}
// 停止滚动
public void stopScroll() {
isStop = true;
}
// 从头开始滚动
public void startFor0() {
currentScrollX = 0;
startScroll();
}
}

xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
android:id="@+id/start"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="start"
android:text="走起" />
android:id="@+id/stop"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="stop"
android:text="停止" />
android:id="@+id/startfor0"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="startFor0"
android:text="从头开始" />
android:id="@+id/test"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="#339320"
android:ellipsize="marquee"
android:singleLine="true"
android:text="这才是真正的文字跑马灯效果这才是真正的字跑马灯效果这才是真正的"
android:textColor="#000000"
android:textSize="20dp" >


MainActivity

public class MainActivity extends Activity {
private MarqueeText test;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
test = (MarqueeText) this.findViewById(R.id.test);
}
public void start(View v) {
test.startScroll();
}
public void stop(View v) {
test.stopScroll();
}
public void startFor0(View v){
test.startFor0();
}
}