android 文字迴圈跑馬燈
阿新 • • 發佈:2018-12-29
程式碼
public class MainActivity extends AppCompatActivity {
private MarqueeText text;
private LinearLayout layout;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
text = (MarqueeText) findViewById(R.id.test);
layout = (LinearLayout) findViewById(R.id.my_layout);
}
public void stop(View v) {
text.stopScroll();
layout.setVisibility(View.GONE);
}
}
public class MarqueeText extends TextView implements Runnable {
private int currentScrollX;//當前滾動的位置
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);
// TODO Auto-generated constructor stub
}
public MarqueeText(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
// TODO Auto-generated constructor stub
}
@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
super.onDraw(canvas);
if (!isMeasure) {//文字寬度只需要獲取一次就可以了
getTextWidth();
isMeasure = true;
}
}
/**
* 獲取文字寬度
*/
private void getTextWidth() {
Paint paint = this.getPaint();
String str = this.getText().toString();
textWidth = (int) paint.measureText(str);
}
@Override
public void run() {
// TODO Auto-generated method stub
currentScrollX -= 2; // Rolling speed
scrollTo(currentScrollX, 0);
if (isStop) {
return;
}
if (getScaleX() <= -(this.getWidth())) {
scrollTo(textWidth, 0);
currentScrollX = textWidth;
//return;
}
postDelayed(this, 5);
}
// start
public void startScroll() {
isStop = false;
this.removeCallbacks(this);
post(this);
}
// stop
public void stopScroll() {
isStop = true;
}
// Start from scratch
public void startFor0() {
currentScrollX = 0;
startScroll();
}
}
佈局檔案
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
android:id="@+id/activity_main"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
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="example.wy.MainActivity">
<LinearLayout
android:id="@+id/my_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:paddingLeft="5dp"
android:background="#e5e2e2"
android:paddingRight="5dp">
<example.wy.MarqueeText
android:id="@+id/test"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1.0"
android:background="#e5e2e2"
android:ellipsize="marquee"
android:focusable="true"
android:focusableInTouchMode="true"
android:marqueeRepeatLimit="marquee_forever"
android:singleLine="true"
android:text="跑馬燈,套馬杆的漢子你威武雄壯"
android:textColor="#000000"
android:textSize="16sp" >
</example.wy.MarqueeText>
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="20dp"
android:background="#e5e2e2"
android:onClick="stop"
android:text="停止"
android:layout_marginLeft="5dp"
android:textSize="16sp" />
</LinearLayout>
</LinearLayout>