iPhone 开发过程中的一些小技术的总结

墨蓝 2022-09-30 11:55 153阅读 0赞

**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。