小编All*_*Bah的帖子

我正在创建一个从网站获取信息的天气应用程序.我最后一次编码(昨晚)一切都很好,我能够编译并运行模拟器,没有任何错误.就在今天,当我启动同一个项目而没有改变任何东西时,我得到了"Apple Mach-O Linker Error".你能帮忙吗？

以下是错误的详细信息:

Ld /Users/Allister/Library/Developer/Xcode/DerivedData/Haze_Meter-dkjjcmjehyitmcbhkcbujnsrhwpu/Build/Products/Debug-iphonesimulator/Haze\ Meter.app/Haze\ Meter normal x86_64
    cd "/Users/Allister/Documents/XCODE/Haze Meter"
    export IPHONEOS_DEPLOYMENT_TARGET=8.3
    export PATH="/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Applications/Xcode.app/Contents/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
    /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -arch x86_64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator8.3.sdk -L/Users/Allister/Library/Developer/Xcode/DerivedData/Haze_Meter-dkjjcmjehyitmcbhkcbujnsrhwpu/Build/Products/Debug-iphonesimulator -F/Users/Allister/Library/Developer/Xcode/DerivedData/Haze_Meter-dkjjcmjehyitmcbhkcbujnsrhwpu/Build/Products/Debug-iphonesimulator -filelist /Users/Allister/Library/Developer/Xcode/DerivedData/Haze_Meter-dkjjcmjehyitmcbhkcbujnsrhwpu/Build/Intermediates/Haze\ Meter.build/Debug-iphonesimulator/Haze\ Meter.build/Objects-normal/x86_64/Haze\ Meter.LinkFileList -Xlinker -rpath -Xlinker @executable_path/Frameworks -Xlinker -objc_abi_version -Xlinker 2 -L/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/iphonesimulator -Xlinker -add_ast_path -Xlinker /Users/Allister/Library/Developer/Xcode/DerivedData/Haze_Meter-dkjjcmjehyitmcbhkcbujnsrhwpu/Build/Intermediates/Haze\ Meter.build/Debug-iphonesimulator/Haze\ Meter.build/Objects-normal/x86_64/Haze_Meter.swiftmodule -mios-simulator-version-min=8.3 -Xlinker -dependency_info -Xlinker /Users/Allister/Library/Developer/Xcode/DerivedData/Haze_Meter-dkjjcmjehyitmcbhkcbujnsrhwpu/Build/Intermediates/Haze\ Meter.build/Debug-iphonesimulator/Haze\ Meter.build/Objects-normal/x86_64/Haze\ Meter_dependency_info.dat -o /Users/Allister/Library/Developer/Xcode/DerivedData/Haze_Meter-dkjjcmjehyitmcbhkcbujnsrhwpu/Build/Products/Debug-iphonesimulator/Haze\ Meter.app/Haze\ Meter

在底部:

ld: file too small (length=0) file '/Users/Allister/Library/Developer/Xcode/DerivedData/Haze_Meter-dkjjcmjehyitmcbhkcbujnsrhwpu/Build/Intermediates/Haze Meter.build/Debug-iphonesimulator/Haze Meter.build/Objects-normal/x86_64/ViewController.o' for architecture x86_64
clang: error: linker command failed with exit code 1 (use …

我在Xcode中使用Swift进行编程,当我想使用实用程序窗格编辑按钮时,我意识到它变得"不适用".属性检查器,连接检查器等都变为"不适用",只有快速帮助检查器仍然显示.

我在故事板中选择了按钮.

任何人都可以帮忙吗？

附上截图..

使用Swift,我该如何制作:

1. 单词"开始"的按钮,在点击时会变为"暂停",反之亦然？不只是一次,但可以无限地完成？(例如在秒表应用程序中)
2. 自定义图像按钮在点击时在2个图像之间切换,也可以无限制地完成(点击和更改)？

我想在Xcode中使用Swift，我要制作：

1）A PICKER，来自数组的数据

2）A BUTTON，当按下时，将LABEL使用来自选定行的文本更新aPICKER

我的代码当前：

var array = ["Sydney", "London", "Washington", "Tokyo", "San Francisco"]

func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
    return 1
}

func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
    return array.count
}

func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String! {
    return array[row]
}

@IBOutlet weak var PICKER: UIPickerView!

@IBOutlet weak var LABEL: UILabel!

@IBAction func BUTTON(sender: AnyObject) {
    LABEL.text = array[PICKER.selectedRowInComponent(0)]
}

到目前为止，一切正常。但是我有两个问题：

1）我应该把“ 0”放进去PICKER.selectedRowInComponent吗？这是什么意思？因为没有数字或任何其他数字都无法正常工作。这不是只选择第一行（而不是选择用户选择的行）吗？ …

我可以在数组中添加字典数组(这是保存多个值的字典键的正确术语吗？)吗？

var dictionary = [String: [String]]()
var array = [String]()

var data1:String = "55a"
var data2:String = "95a"
var data3:String = "66"
var data4:String = "25"
var data5:String = "88b"
var data6:String = "#"

dictionary["3"] = [data1, data2, data3, data4, data5, data6]

var data7:String = "#"
var data8:String = "#"
var data9:String = "#"
var data10:String = "#"
var data11:String = "#"
var data12:String = "#"

dictionary["2"] = [data7, data8, data9, data10, data11, data12]

var data13:String = "100"
var data14:String …

在Swift中,我想在按下按钮B时更改按钮A的标题.

我sender.ButtonA.setTitle("Title", forState: UIControlState.Normal)在IBAction按钮B下试过但它无法工作..反正只是猜测..

我有一些代码viewDidLayoutSubviews,目的是让图像在开始时变得透明(alpha = 0),然后慢慢淡入(进入alpha = 1)代码viewDidAppear.此外,我有一个按钮,按下时可以更改自己的标签文本.

但是,当按下按钮并且标签发生变化时,图像(我在下面指定viewDidLayoutSubviews)也会消失.我认为是因为下面的代码viewDidLayoutSubviews被调用了？

我的问题是:

1)是什么意思viewDidLayoutSubviews？按钮标签更改时为什么会调用它？简单/一般,什么是setNeedsLayout&setNeedsDisplayInRect？

2)那么使用viewWillAppear会更好吗？

这里有两个类似的问题,但我无法理解它们:

1)标签更改时调用viewDidLayoutSubviews(xcode)(swift)

2)为什么viewdidlayoutsubviews多次调用？