如果是Mac 10.6 或 iOS 4.0 之前的平台可以利用 PLBlocks 这个project得以支持Block语法。
Plausible Blocks (PLBlocks) provides a drop-in runtime and toolchain for using blocks in iPhone 2.2+ and Mac OS X 10.5 applications. Both the runtime and compiler patches are direct backports from Apple's Snow Leopard source releases.
项目主页：http://code.google.com/p/plblocks/
下载地址：http://code.google.com/p/plblocks/downloads/list
来自:开源中国社区
