该进程已被中断，请使用“ thread return -x”返回到表达式求值之前的状态

Question

import UIKit

var bOpertation = BlockOperation {
    print("this is a operation 1")
}

bOpertation.addExecutionBlock {
    print("this is a operation 2")
}

bOpertation.addExecutionBlock {
    print("this is a operation 3")
}

print(bOpertation.executionBlocks.count) // the count number is correct.


// Q: why I can't get this object what's wrong ?
bOpertation.executionBlocks[0]

enter "Bug Error" image description here

• 我在操场上测试了这部分代码。

• 我做错什么了吗？

• 什么原因导致了此问题？

• 如何解决此问题？