延迟绑定
Python闭包函数所引用的外部自由变量是延迟绑定的。
In [2]: def multipliers():
...: return [lambda x: i * x for i in range(4)]
In [3]: print [m(2) for m in multipliers()]
[6, 6, 6, 6]
如以上代码: i是闭包函数引用的外部作用域的自由变量, 只有在内部函数被调用的时候才会搜索变量i的值, 由于循环已结束, i指向最终值3, 所以各函数调用都得到了相同的结果。
解决方法:
1) 生成闭包函数的时候立即绑定(使用函数形参的默认值):
In [5]: def multip继续阅读 »
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最近在网上找到了改变的方法，首先来说一下。
more
改变AlertDialog的样式
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xml
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lua
add_cxflags("-I$(buildir)")
它将会在在实际编译的时候，将内置的 buildir 变量转换为实际的构建输出目录：-I./build
并且这些变量在自定义脚本中，也是可以支持的，例如：
lua
target("test")
after_build(target)
print("build ok for $(plat)!")
end
这将会在编译完后，输出：
lua
build ok for macosx!
这些内置变量，大部分都是通过配置的时候，缓存的继续阅读 »
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