使用lapply子集出您想要的元素，并在该列表中将rbind与do.call组合:

Use lapply to subset out the elements you want, and rbind with do.call on that list:

do.call("rbind",lapply(ALIST,function(x) x[["a"]]))
  X1.3
1    1
2    2
3    3
4    1
5    2
6    3
7    1
8    2
9    3