iPhone 开发过程中的一些小技术的…

 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

        floatrotateAngle = 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:[UIImageimageNamed:@"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 = [playerArrayobjectAtIndex:i];
            if(player == nil)
                 break; 
            name = player.playerName;//This "Player1" denotes the player name could also be the computername
            innerDict = [selfgetAllNodeInfoToDictionary:player];
            [rootObj setObject:innerDictforKey:name]; // This "Player1" denotes the person who start thisgame
       }
       player = nil;
       NSData*plistData = [NSPropertyListSerializationdataFromPropertyList:(id)rootObjformat:NSPropertyListXMLFormat_v1_0errorDescription:&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：
        
        
       NSString *documentsPath =[self getDocumentsDirectory]; 
       NSString *savePath =[documentsPathstringByAppendingPathComponent:@"save.plist"];
    
       
       if (plistData) {
                [plistDatawriteToFile:savePath atomically:YES];
        }
        else {
                NSLog(errorDesc);
                [errorDescrelease];
        }

        -(NSString *)getDocumentsDirectory{  
                NSArray*paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);  
                return[pathsobjectAtIndex:0];  
        } 

4 读取plist文件并转化为NSDictionary

        NSString*documentsPath = [self getDocumentsDirectory];
       NSString *fullPath =[documentsPathstringByAppendingPathComponent:@"save.plist"];
       NSMutableDictionary* plistDict= [[NSMutableDictionary alloc]initWithContentsOfFile:fullPath];

5 读取一般性文档文件

        NSString*tmp;
        NSArray*lines; 
        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];
                  [scannerscanUpToString:@"<" intoString:nil];
                  [scannerscanString:@"<" intoString:nil];
                  [scannerscanUpToString:@">"intoString:&stringBetweenBrackets];

                  NSLog([stringBetweenBracketsdescription]);
          }

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。