是否有可能使用标准属性语法将块作为属性?
ARC有什么变化吗?
当前回答
为了子孙后代/完整性的缘故，这里有两个完整的例子，如何实现这种荒谬的多功能“做事方式”。@Robert的回答非常简洁和正确，但在这里我还想展示实际“定义”块的方法。
@interface ReusableClass : NSObject
@property (nonatomic,copy) CALayer*(^layerFromArray)(NSArray*);
@end
@implementation ResusableClass
static NSString const * privateScope = @"Touch my monkey.";
- (CALayer*(^)(NSArray*)) layerFromArray {
return ^CALayer*(NSArray* array){
CALayer *returnLayer = CALayer.layer
for (id thing in array) {
[returnLayer doSomethingCrazy];
[returnLayer setValue:privateScope
forKey:@"anticsAndShenanigans"];
}
return list;
};
}
@end
傻吗?是的。有用吗?地狱啊。这里有一个不同的，“更原子”的方式来设置属性。还有一个非常有用的类……
@interface CALayoutDelegator : NSObject
@property (nonatomic,strong) void(^layoutBlock)(CALayer*);
@end
@implementation CALayoutDelegator
- (id) init {
return self = super.init ?
[self setLayoutBlock: ^(CALayer*layer){
for (CALayer* sub in layer.sublayers)
[sub someDefaultLayoutRoutine];
}], self : nil;
}
- (void) layoutSublayersOfLayer:(CALayer*)layer {
self.layoutBlock ? self.layoutBlock(layer) : nil;
}
@end
这说明了通过访问器(尽管在init中，这是一个有争议的冒险实践..)设置block属性与第一个例子的“非原子”“getter”机制。在任何一种情况下，“硬编码”实现总是可以被覆盖，每个实例。一个拉. .
CALayoutDelegator *littleHelper = CALayoutDelegator.new;
littleHelper.layoutBlock = ^(CALayer*layer){
[layer.sublayers do:^(id sub){ [sub somethingElseEntirely]; }];
};
someLayer.layoutManager = littleHelper;
也. .如果你想在一个类别中添加一个block属性…比如你想要使用Block而不是一些老式的目标/动作“action”…你可以使用相关的值。关联这些块。
typedef void(^NSControlActionBlock)(NSControl*);
@interface NSControl (ActionBlocks)
@property (copy) NSControlActionBlock actionBlock; @end
@implementation NSControl (ActionBlocks)
- (NSControlActionBlock) actionBlock {
// use the "getter" method's selector to store/retrieve the block!
return objc_getAssociatedObject(self, _cmd);
}
- (void) setActionBlock:(NSControlActionBlock)ab {
objc_setAssociatedObject( // save (copy) the block associatively, as categories can't synthesize Ivars.
self, @selector(actionBlock),ab ,OBJC_ASSOCIATION_COPY);
self.target = self; // set self as target (where you call the block)
self.action = @selector(doItYourself); // this is where it's called.
}
- (void) doItYourself {
if (self.actionBlock && self.target == self) self.actionBlock(self);
}
@end
现在，当你做一个按钮，你不需要设置一些IBAction戏剧..只需要在创建时将工作关联起来……
_button.actionBlock = ^(NSControl*thisButton){
[doc open]; [thisButton setEnabled:NO];
};
这种模式可以反复应用到Cocoa API中。使用属性将代码的相关部分更紧密地结合在一起，消除令人费解的委托范例，并利用对象的强大功能，而不仅仅是充当愚蠢的“容器”。
其他回答
@ property(副本)无效
@property (copy)void (^doStuff)(void);
实际的苹果文档，它精确地说明了使用什么:
苹果doco。
你的。h文件:
// Here is a block as a property:
//
// Someone passes you a block. You "hold on to it",
// while you do other stuff. Later, you use the block.
//
// The property 'doStuff' will hold the incoming block.
@property (copy)void (^doStuff)(void);
// Here's a method in your class.
// When someone CALLS this method, they PASS IN a block of code,
// which they want to be performed after the method is finished.
-(void)doSomethingAndThenDoThis:(void(^)(void))pleaseDoMeLater;
// We will hold on to that block of code in "doStuff".
你的。m文件:
-(void)doSomethingAndThenDoThis:(void(^)(void))pleaseDoMeLater
{
// Regarding the incoming block of code, save it for later:
self.doStuff = pleaseDoMeLater;
// Now do other processing, which could follow various paths,
// involve delays, and so on. Then after everything:
[self _alldone];
}
-(void)_alldone
{
NSLog(@"Processing finished, running the completion block.");
// Here's how to run the block:
if ( self.doStuff != nil )
self.doStuff();
}
注意过时的示例代码。
对于现代(2014+)系统，这是正确的和文档化的方法。
为了子孙后代/完整性的缘故，这里有两个完整的例子，如何实现这种荒谬的多功能“做事方式”。@Robert的回答非常简洁和正确，但在这里我还想展示实际“定义”块的方法。
@interface ReusableClass : NSObject
@property (nonatomic,copy) CALayer*(^layerFromArray)(NSArray*);
@end
@implementation ResusableClass
static NSString const * privateScope = @"Touch my monkey.";
- (CALayer*(^)(NSArray*)) layerFromArray {
return ^CALayer*(NSArray* array){
CALayer *returnLayer = CALayer.layer
for (id thing in array) {
[returnLayer doSomethingCrazy];
[returnLayer setValue:privateScope
forKey:@"anticsAndShenanigans"];
}
return list;
};
}
@end
傻吗?是的。有用吗?地狱啊。这里有一个不同的，“更原子”的方式来设置属性。还有一个非常有用的类……
@interface CALayoutDelegator : NSObject
@property (nonatomic,strong) void(^layoutBlock)(CALayer*);
@end
@implementation CALayoutDelegator
- (id) init {
return self = super.init ?
[self setLayoutBlock: ^(CALayer*layer){
for (CALayer* sub in layer.sublayers)
[sub someDefaultLayoutRoutine];
}], self : nil;
}
- (void) layoutSublayersOfLayer:(CALayer*)layer {
self.layoutBlock ? self.layoutBlock(layer) : nil;
}
@end
这说明了通过访问器(尽管在init中，这是一个有争议的冒险实践..)设置block属性与第一个例子的“非原子”“getter”机制。在任何一种情况下，“硬编码”实现总是可以被覆盖，每个实例。一个拉. .
CALayoutDelegator *littleHelper = CALayoutDelegator.new;
littleHelper.layoutBlock = ^(CALayer*layer){
[layer.sublayers do:^(id sub){ [sub somethingElseEntirely]; }];
};
someLayer.layoutManager = littleHelper;
也. .如果你想在一个类别中添加一个block属性…比如你想要使用Block而不是一些老式的目标/动作“action”…你可以使用相关的值。关联这些块。
typedef void(^NSControlActionBlock)(NSControl*);
@interface NSControl (ActionBlocks)
@property (copy) NSControlActionBlock actionBlock; @end
@implementation NSControl (ActionBlocks)
- (NSControlActionBlock) actionBlock {
// use the "getter" method's selector to store/retrieve the block!
return objc_getAssociatedObject(self, _cmd);
}
- (void) setActionBlock:(NSControlActionBlock)ab {
objc_setAssociatedObject( // save (copy) the block associatively, as categories can't synthesize Ivars.
self, @selector(actionBlock),ab ,OBJC_ASSOCIATION_COPY);
self.target = self; // set self as target (where you call the block)
self.action = @selector(doItYourself); // this is where it's called.
}
- (void) doItYourself {
if (self.actionBlock && self.target == self) self.actionBlock(self);
}
@end
现在，当你做一个按钮，你不需要设置一些IBAction戏剧..只需要在创建时将工作关联起来……
_button.actionBlock = ^(NSControl*thisButton){
[doc open]; [thisButton setEnabled:NO];
};
这种模式可以反复应用到Cocoa API中。使用属性将代码的相关部分更紧密地结合在一起，消除令人费解的委托范例，并利用对象的强大功能，而不仅仅是充当愚蠢的“容器”。
@property (nonatomic, copy) void (^simpleBlock)(void);
@property (nonatomic, copy) BOOL (^blockWithParamter)(NSString *input);
如果你要在几个地方重复同一个块，请使用类型def
typedef void(^MyCompletionBlock)(BOOL success, NSError *error);
@property (nonatomic) MyCompletionBlock completion;
您可以遵循下面的格式，并在类中使用testingObjectiveCBlock属性。
typedef void (^testingObjectiveCBlock)(NSString *errorMsg);
@interface MyClass : NSObject
@property (nonatomic, strong) testingObjectiveCBlock testingObjectiveCBlock;
@end
更多信息请看这里
你好,迅速
补充@Francescu的回答。
添加额外参数:
func test(function:String -> String, param1:String, param2:String) -> String
{
return function("test"+param1 + param2)
}
func funcStyle(s:String) -> String
{
return "FUNC__" + s + "__FUNC"
}
let resultFunc = test(funcStyle, "parameter 1", "parameter 2")
let blockStyle:(String) -> String = {s in return "BLOCK__" + s + "__BLOCK"}
let resultBlock = test(blockStyle, "parameter 1", "parameter 2")
let resultAnon = test({(s:String) -> String in return "ANON_" + s + "__ANON" }, "parameter 1", "parameter 2")
println(resultFunc)
println(resultBlock)
println(resultAnon)
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