问题描述
我有一些code，从接收赛格瑞价值和替换，我有索引号数组的某一个元素。
I have some code that receives value from a segue and replaces a certain element of an array with the index number that I have.
变量的初始化：
var noteTitles: [String] = ["Sample Note"]
var noteBodies: [String] = ["This is what lies within"]
var selectedNoteIndex: Int!
var newTitle: String!
var newBody: String!
和我有一个SEGUE，使得最后的3个值，我想他们是。值
and I have a segue that makes the last 3 values the values that I want them to be.
viewDidLoad中（）下，我有这样的：
under viewDidLoad(), I have this:
if newTitle == nil && newBody == nil {
}
else {
println("\(newTitle)")
println("\(newBody)")
println("\(selectedNoteIndex)")
let realTitle: String = newTitle
let realBody: String = newBody
let realIndex: Int = selectedNoteIndex
noteTitles[realIndex] = realTitle
noteBodies[realIndex] = realBody
}
我的日志显示如下：
My logs show this:
New Note Title
This is what lies within
nil
fatal error: unexpectedly found nil while unwrapping an Optional value
和我得到
Thread 1: EXC_BAD_INSTRUCTION(code=EXC_i385_INVOP,subcode=0x0)
就行了。
let realIndex: Int = selectedNoteIndex
谁能告诉我什么，我做错了吗？
Can anyone tell me what I'm doing wrong?
推荐答案
我得到这些错误的原因是因为在segueing返回到主视图，我没有使用正确的开卷SEGUE，而是用另一个节目SEGUE，其中擦除的有previously一直视图控制器内的所有数据。通过创建一个开卷SEGUE，我能够在SEGUE到详细视图和prevent之前保持值的误差。
The reason I was getting these errors is because while segueing back to the main view, I was not using the proper unwind segue, and instead using another show segue, which erased all data that had previously been within the view controller. By creating a unwind segue, I was able to keep the values before the segue to the detail view and prevent the error.
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