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。