在 Objective-C 中,我使用了这种处理完成 block 的方法,现在必须将其转换为 Swift:
在DetailDisplayController.h
typedef void (^AddedCompletitionBlock)(BOOL saved, NSString *primarykey, NSUInteger recordCount);
@interface DetailDisplayController : UITableViewController
@property (nonatomic, copy) AddedCompletitionBlock completionBlock;
@property (strong, nonatomic) Details *detail;
在DetailDisplayController.m
- (void) saveClicked:(id)sender
{
// retrieve PK
NSString *objectId = [[[_detail objectID] URIRepresentation] absoluteString];
if (self.completionBlock != nil)
{
self.completionBlock(_rowChanged, objectId, [_fetchedResultsController.fetchedObjects count]);
}
_rowChanged 和 _fetchedResultsController 是实例变量
在 DetailViewController.m 调用类中,使用传递的 block
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([segue.identifier isEqualToString:@"DetailDisplay"])
{
DetailDisplayController *detailDisplayController = segue.destinationViewController;
...
detailDisplayController.completionBlock = ^(BOOL saved, NSString *sorter, NSUInteger recordCount)
{
if (saved)
...
我如何在 Swift 中执行此操作?
最佳答案
以下是您在 Swift 中需要的等效部分:
typealias AddedCompletionBlock = (saved: Bool, primaryKey: String, recordCount: Int) -> Void
var completionBlock: AddedCompletionBlock? = nil
completionBlock = {saved, primaryKey, recordCount in
print("\(saved), \(primaryKey), \(recordCount)")
}
completionBlock?(saved: true, primaryKey: "key", recordCount: 1)
您可能想好好阅读 "Function Types"和 "Closures" Apple Swift 文档的部分。
关于swift - 如何将完成 block 传递给 Swift 中的另一个类,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/35588661/