iPhone 开发过程中的一些小技术的总结
1 随机数的使用
????????头文件的引用
????????#import <time.h>
????????#import <mach/mach_time.h>
????????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。
