swift 编程报错求解啊

[a2955301]

[ReyZhang]

引用 6 楼 a2955301 的回复:

allButtons[][] 里的[i][j] 改成数字就可以 这是为什么啊

allButtons[i][j] 中的i 或j没有下标越界吧。在使用时不行就先做是否为空的判断

var btn: UIButton = allButtons[i][j] as UIButton
if (btn != nil) {
      btn.setImage(UIImage(named:"gray.png"), forState:UIControlState.Normal)
}

[ReyZhang]

先做一下类型转换试试 var btn: UIButton = allButtons[i][j] as UIButton btn.setImage(UIImage(named:"gray.png"), forState:UIControlState.Normal)

[Bannings]

先把button从allButtons中取出来试试

[a2955301]

不行啊11111

[a2955301]

求代码111111

[a2955301]

allButtons[][] 里的[i][j] 改成数字就可以 这是为什么啊

[a2955301]

var allButtons=[[UIButton]]()

[猿人林克]

我来告诉你正确答案,swift必须要判断数组是否越界，代码如下，应该非常清楚，第一段如果i 随机出来大于3那就会error，第二段任何值都不会有异常，至于多维数组道理一样，请给分谢谢：

var btn = [["11","12"],["21","22"],["31","32"]]
var i = Int(arc4random()) % 9
var j = Int(arc4random()) % 9
print(i)
//if i < btn.count {
    println(btn[i])//error
//}

var btn = [["11","12"],["21","22"],["31","32"]]
var i = Int(arc4random()) % 9
var j = Int(arc4random()) % 9
print(i)
if i < btn.count {
    println(btn[i])
}

[Mr_Rights]

allButtons[i][j]要先转换为具体的类型，比如UIButton