java - 单击按钮时增加和减少自动滚动文本速度

Question

我正在尝试增加和减少按钮单击时自动滚动文本的速度，但我不知道如何做到这一点。我尝试声明默认速度并通过使用按钮来增加和减少其值，但这不起作用。任何帮助都会很棒。请帮助我

ScrollTextView.java:

public class ScrollTextView extends TextView {

public float DEFAULT_SPEED = 9.0f;

public Scroller scroller;
public float speed = DEFAULT_SPEED;
public boolean continuousScrolling = true;

public ScrollTextView(Context context) {
    super(context);
    scrollerInstance(context);
}

public ScrollTextView(Context context, AttributeSet attributes) {
    super(context, attributes);
    scrollerInstance(context);
}

public void scrollerInstance(Context context) {
    scroller = new Scroller(context, new LinearInterpolator());
    setScroller(scroller);
}


@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
    super.onLayout(changed, left, top, right, bottom);
    if (scroller.isFinished()) {
        scroll();
    }
}

public void scroll() {
    int viewHeight = getHeight();
    int visibleHeight = viewHeight - getPaddingBottom() - getPaddingTop();
    int lineHeight = getLineHeight();

    int offset = -1 * visibleHeight;
    int distance = visibleHeight + getLineCount() * lineHeight;
    int duration = (int) (distance * speed);


    scroller.startScroll(0, offset, 0, distance, duration);
}



public void setSpeed(float speed) {
    this.speed = speed;
}

public float getSpeed() {
    return speed;
}

public void setContinuousScrolling(boolean continuousScrolling) {
    this.continuousScrolling = continuousScrolling;
}

public boolean isContinuousScrolling() {
    return continuousScrolling;
}

Answer 1

看看这个Marquee Set Speed

如果您想提高滚动速度，则降低以下值:

private int mRndDuration = 10000;//reduce the value of mRndDuration to increase scrolling speed