iphone开发中的一些小技巧

来源：互联网发布：eclipse格式化js代码编辑：程序博客网时间：2024/05/19 05:33

1 随机数的使用头文件的引用 #import #import srandom()的使用 srandom((unsigned)(mach_absolute_time() & 0xFFFFFFFF)); 直接使用 random() 来调用随机数2 在UIImageView 中旋转图像 float rotateAngle = M_PI; CGAffineTransform transform =CGAffineTransformMakeRotation(rotateAngle); imageView.transform = transform; 以上代码旋转imageView, 角度为rotateAngle, 方向可以自己测试哦！3 在Quartz中如何设置旋转点 UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"bg.png"]]; imageView.layer.anchorPoint = CGPointMake(0.5, 1.0); 这个是把旋转点设置为底部中间。记住是在QuartzCore.framework中才得到支持。4 创建.plist文件并存储 NSString *errorDesc; //用来存放错误信息 NSMutableDictionary *rootObj = [NSMutableDictionary dictionaryWithCapacity:4]; //NSDictionary, NSData等文件可以直接转化为plist文件 NSDictionary *innerDict; NSString *name; Player *player; NSInteger saveIndex; for(int i = 0; i < [playerArray count]; i++) { player = nil; player = [playerArray objectAtIndex:i]; if(player == nil) break; name = player.playerName;// This "Player1" denotes the player name could also be the computer name innerDict = [self getAllNodeInfoToDictionary:player]; [rootObj setObject:innerDict forKey:name]; // This "Player1" denotes the person who start this game } player = nil; NSData *plistData = [NSPropertyListSerialization dataFromPropertyList:(id)rootObj format:NSPropertyListXMLFormat_v1_0 errorDescription:&errorDesc]; 红色部分可以忽略，只是给rootObj添加一点内容。这个plistData为创建好的plist文件，用其writeToFile方法就可以写成文件。下面是代码： /*得到移动设备上的文件存放位置*/ NSString *documentsPath = [self getDocumentsDirectory]; NSString *savePath = [documentsPath stringByAppendingPathComponent:@"save.plist"]; /*存文件*/ if (plistData) { [plistData writeToFile:savePath atomically:YES]; } else { NSLog(errorDesc); [errorDesc release]; } - (NSString *)getDocumentsDirectory { NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); return [paths objectAtIndex:0]; } 4 读取plist文件并转化为NSDictionary NSString *documentsPath = [self getDocumentsDirectory]; NSString *fullPath = [documentsPath stringByAppendingPathComponent:@"save.plist"]; NSMutableDictionary* plistDict = [[NSMutableDictionary alloc] initWithContentsOfFile:fullPath];5 读取一般性文档文件 NSString *tmp; NSArray *lines; /*将文件转化为一行一行的*/ lines = [[NSString stringWithContentsOfFile:@"testFileReadLines.txt"] componentsSeparatedByString:@"/n"]; NSEnumerator *nse = [lines objectEnumerator]; // 读取<>里的内容 while(tmp = [nse nextObject]) { NSString *stringBetweenBrackets = nil; NSScanner *scanner = [NSScanner scannerWithString:tmp]; [scanner scanUpToString:@"<" intoString:nil]; [scanner scanString:@"<" intoString:nil]; [scanner scanUpToString:@">" intoString:&stringBetweenBrackets]; NSLog([stringBetweenBrackets description]); }对于读写文件，还有补充，暂时到此。随机数和文件读写在游戏开发中经常用到。所以把部分内容放在这，以便和大家分享，也当记录，便于查找。6 隐藏NavigationBar[self.navigationController setNavigationBarHidden:YES animated:YES];在想隐藏的ViewController中使用就可以了。