我想做这样的事情:
try {
SomeObjectiveClass.someMethod()
catch Error {
print("Recovered objc crash from Swift!")
}
我正在构建一个应用程序,在其中输入一些视觉约束,然后我会收到结果或有关任何错误的消息。
现在,每次我输入错误的约束时,应用程序都会崩溃,但我想显示一个包含错误的对话框并让用户重试。
在我的情况下,我没有“NSError-to- throws”自动翻译。
最佳答案
考虑这个类:
@implementation SomeObjectiveClass
+ (BOOL)someClassMethodWithError:(NSError **)error {
// some something that
if (everythingOk) {
return true;
} else {
if (error) {
*error = [NSError errorWithDomain:kMyDomain code:kSomeErrorCode userInfo:@{NSLocalizedDescriptionKey : @"Some error message"}];
}
return false;
}
}
- (BOOL)someInstanceMethodWithError:(NSError **)error {
// some something that
if (everythingOk) {
return true;
} else {
if (error) {
*error = [NSError errorWithDomain:kMyDomain code:kSomeOtherErrorCode userInfo:@{NSLocalizedDescriptionKey : @"Some error message"}];
}
return false;
}
}
@end
然后您可以像这样捕获这些错误:
do {
try SomeObjectiveClass.someClassMethod()
// or
let object = SomeObjectiveClass()
try object.someInstanceMethod()
} catch {
print("Recovered \(error) from Swift!")
}
请注意,这种错误捕获不应与我们过去能够在 Objective-C 中执行的异常处理相混淆。开发过程中应消除异常情况。上述内容适用于合法的运行时错误(例如,网络请求失败或由于程序员无法控制的条件而可能发生的其他错误)。
引自Using Swift with Cocoa and Objective-C :
Although Swift error handling resembles exception handling in Objective-C, it is entirely separate functionality. If an Objective-C method throws an exception during runtime, Swift triggers a runtime error. There is no way to recover from Objective-C exceptions directly in Swift. Any exception handling behavior must be implemented in Objective-C code used by Swift.
关于objective-c - 是否可以从 Swift 代码中捕获 Objective-C 错误?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/33977872/