如何从Objective-C将以下内容转换为Swift?
if (myVar) return;
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Swift不在条件周围使用括号,但是下面的代码给出了错误.
if myVar return
Run Code Online (Sandbox Code Playgroud) 当模态呈现或推送接口控制器时,我们可以指定context
参数以将一些数据传递给新控制器,如下所示.
// Push
[self pushControllerWithName:@"MyController" context:[NSDictionary dictionaryWithObjectsAndKeys:someObject, @"someKey", ..., nil]];
// Modal
[self presentControllerWithName:@"MyController" context:[NSDictionary dictionaryWithObjectsAndKeys:someObject, @"someKey", ..., nil]];
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我的问题是,我们怎么能这样做呢?
假设我们以模态方式呈现一个控制器,以便用户从列表中选择一个项目,然后我们返回主控制器,我们如何获取已被选中的项目?
是否有任何框架允许RESTful API服务器用C#编写?
我见过MVC 4,但是这似乎提供了一个你可以在浏览器中看到的视图,我只需要API服务器而没有视图.如果它能够提供流API也会很棒.
谢谢
超过2天我一直试图修复此错误,但我没有成功.
这是错误:
无法解决"mscorlib,Version = 2.0.5.0,Culture = neutral,PublicKeyToken = 7cec85d7bea7798e"和"mscorlib"之间的冲突.任意选择"mscorlib,Version = 2.0.5.0,Culture = neutral,PublicKeyToken = 7cec85d7bea7798e".
我搜索了它,很多人都有这个问题,但我找不到解决方案.
最后,我们如何找到解决这两个引用之间冲突的方法?
正如标题所示,我有一个UICollectionView
与UIViewController
IB通过的联系.我有一个UICollectionView
叫做的子类imageCell
.在viewcontroller viewDidLoad
方法中,我注册了这样的类:
CGRect collectionViewRect = CGRectMake(384, 60, 728, 924);
UICollectionViewFlowLayout *flow = [[UICollectionViewFlowLayout alloc] init];
imageCollectionView = [[UICollectionView alloc] initWithFrame:collectionViewRect collectionViewLayout:flow];
[imageCollectionView registerClass:[imageCell class] forCellWithReuseIdentifier:@"Cell"];
imageCollectionView.delegate = self;
imageCollectionView.dataSource = self;
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然后我调用一个名为getPhotos
in viewDidAppear
(因为UI原因)的方法,该方法从服务中获取照片,然后我[imagCcollectionView reloadData];
在里面调用getPhotos
.
然后在cellForItemAtIndexPath
我做以下事情:
imageCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"Cell" forIndexPath:indexPath];
GRKAlbum *album = [albums objectAtIndex:indexPath.item];
cell.titleLabel.text = album.name;
return cell;
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我知道我在这里做错了什么,因为这个方法被调用而cell
不是nil
,也不是album
.
所以,当我运行所有这些代码时,会UICollectionView
出现,但没有任何内容.我只能看到背景颜色collectionView …
我在pod文件中添加了Fabric和Crashlytics.当我更新pods时,我遇到带有重复符号的链接器错误.我在这里发现它在Fabric.framework和Crashlytics.framework中都有相同的文件但是如何从我的角度解决这个问题呢?
duplicate symbol _CLSMachOEnumerateSlicesAtAddress in:
Location/Crashlytics.framework/Crashlytics(CLSMachO.o)
Location/Pods/Fabric/iOS/Fabric.framework/Fabric(CLSMachO.o)
duplicate symbol _CLSMachOFileDestroy in:
Location/Crashlytics.framework/Crashlytics(CLSMachO.o)
Location/Pods/Fabric/iOS/Fabric.framework/Fabric(CLSMachO.o)
duplicate symbol _CLSMachOFileEnumerateSlices in:
Location/Crashlytics.framework/Crashlytics(CLSMachO.o)
Location/Pods/Fabric/iOS/Fabric.framework/Fabric(CLSMachO.o)
duplicate symbol _CLSMachOFileInitWithPath in:
Location/Crashlytics.framework/Crashlytics(CLSMachO.o)
Location/Pods/Fabric/iOS/Fabric.framework/Fabric(CLSMachO.o)
duplicate symbol _CLSMachOGetDylibPath in:
Location/Crashlytics.framework/Crashlytics(CLSMachO.o)
Location/Pods/Fabric/iOS/Fabric.framework/Fabric(CLSMachO.o)
duplicate symbol _CLSMachOGetEncrypted in:
Location/Crashlytics.framework/Crashlytics(CLSMachO.o)
Location/Pods/Fabric/iOS/Fabric.framework/Fabric(CLSMachO.o)
duplicate symbol _CLSMachOGetLinkedSDKVersion in:
Location/Crashlytics.framework/Crashlytics(CLSMachO.o)
Location/Pods/Fabric/iOS/Fabric.framework/Fabric(CLSMachO.o)
duplicate symbol _CLSMachOGetMinimumOSVersion in:
Location/Crashlytics.framework/Crashlytics(CLSMachO.o)
Location/Pods/Fabric/iOS/Fabric.framework/Fabric(CLSMachO.o)
duplicate symbol _CLSMachOGetUUID in:
Location/Crashlytics.framework/Crashlytics(CLSMachO.o)
Location/Pods/Fabric/iOS/Fabric.framework/Fabric(CLSMachO.o)
duplicate symbol _CLSMachONormalizeUUID in:
Location/Crashlytics.framework/Crashlytics(CLSMachO.o)
Location/Pods/Fabric/iOS/Fabric.framework/Fabric(CLSMachO.o)
duplicate symbol _CLSMachOSliceEnumerateLoadCommands in:
Location/Crashlytics.framework/Crashlytics(CLSMachO.o)
Location/Pods/Fabric/iOS/Fabric.framework/Fabric(CLSMachO.o)
duplicate symbol _CLSMachOSliceGetArchitectureName in:
Location/Crashlytics.framework/Crashlytics(CLSMachO.o)
Location/Pods/Fabric/iOS/Fabric.framework/Fabric(CLSMachO.o)
duplicate symbol _CLSMachOSliceGetCurrent in:
Location/Crashlytics.framework/Crashlytics(CLSMachO.o)
Location/Pods/Fabric/iOS/Fabric.framework/Fabric(CLSMachO.o)
duplicate …
Run Code Online (Sandbox Code Playgroud) 我正在使用CABasicAnimation UIImageView
顺时针旋转90度,但我需要让它在最初90度旋转后从其位置再旋转90度.
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
animation.duration = 10;
animation.additive = YES;
animation.removedOnCompletion = NO;
animation.fillMode = kCAFillModeForwards;
animation.fromValue = [NSNumber numberWithFloat:DEGREES_TO_RADIANS(0)];
animation.toValue = [NSNumber numberWithFloat:DEGREES_TO_RADIANS(90)];
[_myview.layer addAnimation:animation forKey:@"90rotation"];
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使用上面的代码最初工作,图像保持90度角.如果我再次调用它使其再旋转90度,则动画开始时跳回0并旋转90度,而不是90度到180度.
我的印象是,animation.additive = YES;
会导致进一步的动画使用当前状态作为起点.
有任何想法吗?
是否可以在故事板中的一个场景中隐藏状态栏?
例如:
我希望它隐藏在"ViewController A"中,但是当通过a移动segue
到"ViewController B"(例如,a Navigation Controller
)时,将显示状态栏.
我知道你可以在整个应用程序中禁用它,但是你怎么做只为一个ViewController
?
从下面的建议确实有效,但是当切换到Navigation Controller
它时似乎导致导航栏被绘制在错误的位置.
我班上有一个NSInteger就像这样
在@interface中:
NSInteger currentRow;
@property (assign) NSInteger currentRow;
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在@implementation中:
@synthesize currentRow;
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做[self setCurrentRow:0]
似乎工作正常,但[self currentRow]
由于某种原因使用只返回null,不知道为什么.当使用断点时,我可以看到它的值currentRow
是0
如此设置正常,但我无法获得该值.
我有以下代码.prompt
是一个UIAlertController
.
self.presentViewController(prompt, animated: true, completion: {
prompt.textFields[0].becomeFirstResponder()
})
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但它给了我这个错误:Could not find member 'becomeFirstResponder'
.
然而,如果我把它放在它的工作正常:
self.presentViewController(prompt, animated: true, completion: {
let foo = 0
prompt.textFields[0].becomeFirstResponder()
})
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当我添加如上所述的无用代码行时,为什么错误会消失?
ios ×7
objective-c ×3
c# ×2
swift ×2
api ×1
apple-watch ×1
cocoa ×1
crashlytics ×1
macos ×1
rest ×1
storyboard ×1
swift3 ×1
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