IOS开发问题汇总

7.真机模拟内存警告： [[UIApplication sharedApplication] _performMemoryWarning];

8.如果没法连接模拟器或真机了:删除DerivedData目录，并且清空回收站,也许还要重启xcode4.

1.运行即崩溃，log下面提示：

Couldn't register com.myApp.debug with the bootstrap server. Error: unknown error code. This generally means that another instance of this process was already running or is hung in the debugger.Program received signal: “SIGABRT”.

解决办法：重启iphone/ipad系统

2.使用Three20框架，加载图片失败，log以下提示：

TTDASSERT failed: 0 == _queue.maxContentLength contentLength <=_queue.maxContentLength

解决办法：在appDelegate中加入

[[TTURLRequestQueue mainQueue] setMaxContentLength:0];

3.一个object被dealloc之后，其指针还存在，但指向的内存伟空，为了防止其他地方判断该object是否为nil的时候出现bad access问题，就应该立即写一句object ＝ nil；

4.UINavigationBar的tintColor变了，backItem的颜色不变的问题解决方案:

@interface UINavigationController (RefreshBackItem)
- (void)refreshBackItem;
@end

@implementation UINavigationController (RefreshBackItem)
- (void)refreshBackItem
{
    UINavigationBar *bar = self.navigationBar;
    UINavigationItem *backItem = bar.backItem;
    NSString *title = [backItem title];
    backItem.title = @"";
    backItem.title = title;
}
@end

5 清除通知中心的本程序消息：
[application cancelAllLocalNotifications];
[application setApplicationIconBadgeNumber:0];

- (BOOL) isiPad

{
    return [[self model] isEqualToString:@"iPad Simulator"] || [[self platform] rangeOfString:@"iPad"].location == 0;
}

- (BOOL) isRetinaDisplay
{
    return  ([[UIScreen mainScreen] respondsToSelector:@selector(scale)] == YES && [[UIScreen mainScreen] scale] == 2.00);
}

-(BOOL)isNewiPad
{
        return ([self isiPad] && [self isRetinaDisplay]);
}