场景描述：产品故意整事，狂点一个页面跳转按钮，然而那个页面的展示时需要初始化一个第三方的SDK，导致一个启动模式为 android:launchMode="singleTop"的页面Activity重复新建了多次。

1、解决思路查看源码：startActivity(intent);

发现是调用了

 @Override
    public void startActivity(Intent intent, @Nullable Bundle options) {
        if (options != null) {
            startActivityForResult(intent, -1, options);
        } else {
            // Note we want to go through this call for compatibility with
            // applications that may have overridden the method.
            startActivityForResult(intent, -1);
        }
    }

也就是说我这边只要重写 startActivityForResult()方法就好

2、重写 startActivityForResult()

 /**
     * 每次启动activity都会调用此方法
     */
    @SuppressLint("RestrictedApi")
    @Override
    public void startActivityForResult(Intent intent, int requestCode, @Nullable Bundle options) {
        if (!isFastClick()) {
            super.startActivityForResult(intent, requestCode, options);
        }
    }

可能注意到了if (!isFastClick()) {},就是在这做判断

3、判断是否快速点击 isFastClick()

  /**
     * 检查是否重复跳转，不需要则重写方法并返回true
     */
    // 两次点击间隔不能少于1000ms
    private static final int FAST_CLICK_DELAY_TIME = 1000;
    private static long lastClickTime;

    public static boolean isFastClick() {
        boolean flag = true;
        long currentClickTime = System.currentTimeMillis();
        if ((currentClickTime - lastClickTime) >= FAST_CLICK_DELAY_TIME ) {
            flag = false;
        }
        lastClickTime = currentClickTime;
        return flag;
    }