Android之AOP架构<第二篇>：按钮防抖

这里就直接贴出代码实现了。

[第一步] 自定义注解

ClickLimit.java

@Target({ElementType.METHOD })
@Retention(RetentionPolicy.RUNTIME)
public @interface ClickLimit {
    int value() default 500;
}

[第二步] 切面定义

@Aspect
public class ClickLimitAspect {

    private static final int CHECK_FOR_DEFAULT_TIME = 500;

    private static final String POINTCUT_ON_ANNOTATION =
            "execution(@com.example.aopdemo.ClickLimit * *(..))";

    @Pointcut(POINTCUT_ON_ANNOTATION)
    public void onAnnotationClick(){}

    @Around("onAnnotationClick()")
    public void processJoinPoint(ProceedingJoinPoint joinPoint) throws Throwable {
        try {
            Signature signature = joinPoint.getSignature();
            if (!(signature instanceof MethodSignature)){
                joinPoint.proceed();
                return;
            }
            MethodSignature methodSignature = (MethodSignature) signature;
            Method method = methodSignature.getMethod();
            boolean isHasLimitAnnotation = method.isAnnotationPresent(ClickLimit.class);
            String methodName = method.getName();
            int intervalTime = CHECK_FOR_DEFAULT_TIME;
            if (isHasLimitAnnotation){
                ClickLimit clickLimit = method.getAnnotation(ClickLimit.class);
                int limitTime = clickLimit.value();
                if (limitTime <= 0){
                    joinPoint.proceed();
                    return;
                }
                intervalTime = limitTime;
            }
            Object[] args = joinPoint.getArgs();
            View view = getViewFromArgs(args);
            if (view == null) {
                joinPoint.proceed();
                return;
            }
            Object viewTimeTag =  view.getTag(R.integer.xt_click_limit_tag_view);
            if (viewTimeTag == null){
                proceedAnSetTimeTag(joinPoint, view);
                return;
            }
            long lastClickTime = (long) viewTimeTag;
            if (lastClickTime <= 0){
                proceedAnSetTimeTag(joinPoint, view);
                return;
            }

            if (!canClick(lastClickTime, intervalTime)){
                return;
            }
            proceedAnSetTimeTag(joinPoint, view);
        } catch (Throwable e) {
            e.printStackTrace();
            joinPoint.proceed();
        }
    }

    public void proceedAnSetTimeTag(ProceedingJoinPoint joinPoint, View view) throws Throwable {
        view.setTag(R.integer.xt_click_limit_tag_view, System.currentTimeMillis());
        joinPoint.proceed();
    }

    public View getViewFromArgs(Object[] args) {
        if (args != null && args.length > 0) {
            Object arg = args[0];
            if (arg instanceof View) {
                return (View) arg;
            }
        }
        return null;
    }

    public boolean canClick(long lastClickTime, int intervalTime) {
        long currentTime = System.currentTimeMillis();
        long realIntervalTime  = currentTime - lastClickTime;
        return realIntervalTime >= intervalTime;
    }

}

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <integer name="xt_click_limit_tag_view">0x01</integer>
</resources>

[第三步] 在指定点击事件中添加注解

    button.setOnClickListener(new View.OnClickListener() {
        @Override
        @ClickLimit(5000)
        public void onClick(View v) {
            test();
        }
    });

@ClickLimit的默认值为500，当然，也可以根据自己的医院随意修改。

以上代码可以让点击事件每5秒才能点击一次。

[本章完...]