本文实例为大家分享了Android自定义跑马灯文字的具体代码，供大家参考，具体内容如下
Android 跑马灯效果文字：
效果图（真实动画很流畅，这个转gif有问题，感觉有点卡）：
代码:
public class MarqueeHorizontalTextView extends AppCompatTextView {
private float textLength = 0f;
private float drawTextX = 0f;// 文本的横坐标
public boolean isStarting = false;// 是否开始滚动
private Paint paint = null;
private String text = "";
private long waitTime = 1000; //开始时等待的时间
private int scrollTile = 2; //文字的滚动速度
private int baseline;
public MarqueeHorizontalTextView(Context context) {
super(context);
initView(context);
}
public MarqueeHorizontalTextView(Context context, AttributeSet attrs) {
super(context, attrs);
initView(context);
}
public MarqueeHorizontalTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
initView(context);
}
private void initView(Context context) {
setMaxWidth(context.getResources().getDisplayMetrics().widthPixels / 2); //因为需求需要所以设置了最大宽度，如果不需要此功能可以删除掉
paint = getPaint();
paint.setColor(getTextColors().getColorForState(getDrawableState(), 0));
text = getText().toString();
if (TextUtils.isEmpty(text)) {
return;
}
textLength = paint.measureText(text);
isStarting = true;
}
@Override
public void setTextColor(int color) {
super.setTextColor(color);
paint.setColor(color);
start();
}
@Override
public void setText(CharSequence text, BufferType type) {
super.setText(text, type);
this.text = text.toString();
this.textLength = getPaint().measureText(text.toString());
drawTextX = 0;
start();
}
public void start() {
isStarting = true;
invalidate();
}
public void stop() {
isStarting = false;
invalidate();
}
@Override
public void onDraw(Canvas canvas) {
final Paint.FontMetricsInt fontMetrics = paint.getFontMetricsInt();
baseline = (canvas.getHeight() - fontMetrics.bottom - fontMetrics.top) / 2;
if (textLength <= canvas.getWidth()) {
canvas.drawText(text, 0, baseline, paint);
return;
}
canvas.drawText(text, -drawTextX, baseline, paint);
if (!isStarting) {
return;
}
if (drawTextX == 0) {
postDelayed(() -> {
drawTextX = 1;
isStarting = true;
invalidate();
}, waitTime);
isStarting = false;
return;
}
drawTextX += scrollTile;
//判断是否滚动结束
if (drawTextX > textLength) {
drawTextX = -canvas.getWidth();
}
invalidate();
}
}
