solve nstimer retain cycle

MZTimerLabel.xcodeproj/project.pbxproj

@@ -7,6 +7,8 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		279565FD1E013A1700ABA8B6 /* NSTimer+Block.h in Headers */ = {isa = PBXBuildFile; fileRef = 279565FB1E013A1700ABA8B6 /* NSTimer+Block.h */; };
+		279565FE1E013A1700ABA8B6 /* NSTimer+Block.m in Sources */ = {isa = PBXBuildFile; fileRef = 279565FC1E013A1700ABA8B6 /* NSTimer+Block.m */; };
 		40A965371AD4CDB700B2D499 /* MZTimerLabel.h in Headers */ = {isa = PBXBuildFile; fileRef = 40A965111AD4CAF500B2D499 /* MZTimerLabel.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		40A965381AD4CDBD00B2D499 /* MZTimerLabel.m in Sources */ = {isa = PBXBuildFile; fileRef = 40A965121AD4CAF500B2D499 /* MZTimerLabel.m */; };
 /* End PBXBuildFile section */
@@ -22,6 +24,8 @@
 /* End PBXContainerItemProxy section */
 
 /* Begin PBXFileReference section */
+		279565FB1E013A1700ABA8B6 /* NSTimer+Block.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = "NSTimer+Block.h"; sourceTree = "<group>"; };
+		279565FC1E013A1700ABA8B6 /* NSTimer+Block.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = "NSTimer+Block.m"; sourceTree = "<group>"; };
 		40A965111AD4CAF500B2D499 /* MZTimerLabel.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = MZTimerLabel.h; sourceTree = "<group>"; };
 		40A965121AD4CAF500B2D499 /* MZTimerLabel.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = MZTimerLabel.m; sourceTree = "<group>"; };
 		40A9651A1AD4CB5F00B2D499 /* MZTimerLabel.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = MZTimerLabel.framework; sourceTree = BUILT_PRODUCTS_DIR; };
@@ -67,6 +71,8 @@
 		40A9651C1AD4CB5F00B2D499 /* MZTimerLabel */ = {
 			isa = PBXGroup;
 			children = (
+				279565FB1E013A1700ABA8B6 /* NSTimer+Block.h */,
+				279565FC1E013A1700ABA8B6 /* NSTimer+Block.m */,
 				40A965111AD4CAF500B2D499 /* MZTimerLabel.h */,
 				40A965121AD4CAF500B2D499 /* MZTimerLabel.m */,
 				40A9651D1AD4CB5F00B2D499 /* Supporting Files */,
@@ -90,6 +96,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				40A965371AD4CDB700B2D499 /* MZTimerLabel.h in Headers */,
+				279565FD1E013A1700ABA8B6 /* NSTimer+Block.h in Headers */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -188,6 +195,7 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				279565FE1E013A1700ABA8B6 /* NSTimer+Block.m in Sources */,
 				40A965381AD4CDBD00B2D499 /* MZTimerLabel.m in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;

MZTimerLabel/MZTimerLabel.m

@@ -27,7 +27,7 @@
 // THE SOFTWARE.
 
 #import "MZTimerLabel.h"
-
+#import "NSTimer+Block.h"
 
 #define kDefaultTimeFormat  @"HH:mm:ss"
 #define kHourFormatReplace  @"!!!*"
@@ -243,10 +243,38 @@ -(void)start{
         _timer = nil;
     }
 
-    if ([self.timeFormat rangeOfString:@"SS"].location != NSNotFound) {
-        _timer = [NSTimer scheduledTimerWithTimeInterval:kDefaultFireIntervalHighUse target:self selector:@selector(updateLabel) userInfo:nil repeats:YES];
+    CGFloat precision;
+
+    if ([self.timeFormat rangeOfString:@"SS"].location != NSNotFound){
+
+        precision = kDefaultFireIntervalHighUse;
+    }else{
+
+        precision = kDefaultFireIntervalNormal;
+    }
+
+    __weak typeof(self)weakself = self;
+
+    if ([NSTimer respondsToSelector:@selector(scheduledTimerWithTimeInterval:repeats:block:)]) {
+
+        _timer = [NSTimer scheduledTimerWithTimeInterval:precision
+                                                 repeats:YES
+                                                   block:^(NSTimer * _Nonnull timer) {
+                                                       __strong typeof(weakself)strongself = weakself;
+                                                       if (strongself) {
+                                                           [strongself updateLabel];
+                                                       }
+                                                   }];
     }else{
-        _timer = [NSTimer scheduledTimerWithTimeInterval:kDefaultFireIntervalNormal target:self selector:@selector(updateLabel) userInfo:nil repeats:YES];
+
+        _timer = [NSTimer scheduledTimerWithTimeInterval:precision
+                                                   block:^{
+                                                        __strong typeof(weakself)strongself = weakself;
+                                                        if (strongself) {
+                                                            [strongself updateLabel];
+                                                        }
+                                                   }
+                                                 repeats:YES];
     }
     [[NSRunLoop currentRunLoop] addTimer:_timer forMode:NSRunLoopCommonModes];
 

MZTimerLabel/NSTimer+Block.h

@@ -0,0 +1,23 @@
+//
+//  NSTimer+Block.h
+//  SuperCalculator
+//
+//  Created by Peng Wang on 2016/12/14.
+//  Copyright © 2016年 youdao. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+
+/**
+ NSTimer (Block) is used to solving retain cycle below ios10.0
+
+ if is ios10.0 ,we can use method:
+ + (NSTimer *)scheduledTimerWithTimeInterval:(NSTimeInterval)interval repeats:(BOOL)repeats block:(void (^)(NSTimer *timer))block API_AVAILABLE(macosx(10.12), ios(10.0), watchos(3.0), tvos(10.0));
+
+ */
+@interface NSTimer (Block)
+
++ (NSTimer*)scheduledTimerWithTimeInterval:(NSTimeInterval)interval block:(void(^)())block repeats:(BOOL)repeats;
+
+@end

MZTimerLabel/NSTimer+Block.m

@@ -0,0 +1,30 @@
+//
+//  NSTimer+Block.m
+//  SuperCalculator
+//
+//  Created by Peng Wang on 2016/12/14.
+//  Copyright © 2016年 youdao. All rights reserved.
+//
+
+#import "NSTimer+Block.h"
+
+@implementation NSTimer (Block)
+
++ (NSTimer*)scheduledTimerWithTimeInterval:(NSTimeInterval)interval block:(void(^)())block repeats:(BOOL)repeats{
+
+    return [self scheduledTimerWithTimeInterval:interval
+                                         target:self
+                                       selector:@selector(blockInvoke:)
+                                       userInfo:[block copy]
+                                        repeats:repeats];
+}
+
++ (void)blockInvoke:(NSTimer*)timer {
+
+    void (^block)() = timer.userInfo;
+    if (block) {
+        block();
+    }
+}
+
+@end