我有以下代码,但我没有得到预期的结果。
#import "CancelPerformSelectorTestAppDelegate.h"
@implementation CancelPerformSelectorTestAppDelegate
@synthesize window;
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
[window makeKeyAndVisible];
for(unsigned int i = 0; i < 10; i++){
NSTimeInterval waitThisLong = i;
[self performSelector:@selector(foo) withObject:nil afterDelay: waitThisLong];
}
[[NSRunLoop currentRunLoop] cancelPerformSelectorsWithTarget: self];
return YES;
}
- (void) foo {
static unsigned int timesCalled = 0;
++timesCalled;
NSLog(@"%s: I am called for the %d-st/nd/th time", __func__, timesCalled);
}
- (void)applicationWillResignActive:(UIApplication *)application {}
- (void)applicationDidBecomeActive:(UIApplication *)application {}
- (void)applicationWillTerminate:(UIApplication *)application {}
- (void)applicationDidReceiveMemoryWarning:(UIApplication *)application {}
- (void)dealloc {
[window release];
[super dealloc];
}
@end
我希望函数被调用大约0次,如果CPU有一个缓慢的一天,可能是1。
该功能将执行10次! :(总是。我做错了什么,我怎么能达到我预期的结果?
非常感谢,很多, 尼克
答案 0 :(得分:5)
您想使用NSObject类方法取消请求+ cancelPreviousPerformRequestsWithTarget:
例如,
[NSObject cancelPreviousPerformRequestsWithTarget:self];
的“处理点击手势”部分中有一个示例
答案 1 :(得分:1)
你想要这个:
[UIApplication cancelPreviousPerformRequestsWithTarget:self];