OC学习笔记21--OC中集合类的读写文件操作及NSData与NSValue

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#import <Foundation/Foundation.h>   // 定义一个Scores结构体typedef struct {double mathScore,engScore,cScore;} Scores;NSString * NSStringFromScores(Scores s);int main(int argc, const char * argv[])  {            NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];    NSFileManager *fm=[NSFileManager defaultManager];        NSString * aryPath= @"C:/Users/Administrator/Desktop/ary.xml";   NSString * dictPath= @"C:/Users/Administrator/Desktop/dict.xml";      // *1> OC数组的读写文件操作   NSArray *sary= [NSArray arrayWithObjects:@"Jack",@"Tommy",@"Bolt",nil];   BOOL aryFlag=[sary writeToFile:aryPath atomically:YES];   if(aryFlag)   {   sary=[NSArray arrayWithContentsOfFile:aryPath];   NSLog(@"\naryFromFile=\n%@",sary);   }      // *2> OC字典的读写文件操作   NSMutableDictionary * dict = [NSMutableDictionary dictionary];   [dict setValue:sary forKey:@"ary"];   [dict setValue:aryPath forKey:@"aryPath"];   BOOL dictFlag=[dict writeToFile:dictPath atomically:YES];   if(dictFlag)   {   dict=[NSMutableDictionary dictionaryWithContentsOfFile:dictPath];   NSLog(@"\ndictFromFile=\n%@",dict);   }         // *3> OCstr的序列化与反序列化   NSString * path= @"C:/Users/Administrator/Desktop/str.txt";   // 将OCstr按某种编码方式encode成bytes保存在NSData   NSData *data=[@"this is an NSData test!!\n" dataUsingEncoding:NSUTF8StringEncoding];   // 将bytes写入文件   BOOL strPathFlag=[fm createFileAtPath:path contents:data attributes:nil];   if(strPathFlag)   {   // 从文件读取bytes保存为NSData类型NSData *strData=[fm contentsAtPath:path];// 将bytes按某种解码方式decode成OCstrNSString *strFromData=[[[NSString alloc] initWithData:strDataencoding:NSUTF8StringEncoding] autorelease];NSLog(@"\nstrFromData=%@",strFromData);      }            // *4> struct与NSValue的互相转换   Scores scores1={66.0,77.0,88.0},scores2={0},* scores3={0};   // 将struct包装成NSValue，@encode(Type)将struct类型转换成(char *)类型   NSValue *scoresVal=[NSValue valueWithBytes:&scores1 objCType:@encode(Scores)];   // 从NSValue中取出struct   [scoresVal getValue:&scores2];   NSLog(@"\nscoresValFromStruct=%@\nscores2FromNSValue=%@",scoresVal,NSStringFromScores(scores2));         // *5> 将数据按照其在内存中的bytes写入文件，并将文件中的bytes读入内存   NSString * bytePath= @"C:/Users/Administrator/Desktop/byte.txt";   // 将struct按照其内存中的bytes保存到NSData对象   NSData *data2=[NSData dataWithBytes:&scores2 length:sizeof(Scores)];   // 将bytes写入文件    BOOL bytePathFlag=[fm createFileAtPath:bytePath contents:data2 attributes:nil];   if(bytePathFlag)   {   // 从文件读取bytes保存到NSData对象   NSData *data3=[fm contentsAtPath:bytePath];   // 取出NSData对象中的bytes，转换成struct   scores3=(Scores *)[data2 bytes];   NSLog(@"\nscores3FromNSData=%@",NSStringFromScores(*scores3));   }          [pool drain];    return 0;} // 将Scores结构体转字符串NSString * NSStringFromScores(Scores s){return [NSString stringWithFormat:@"{ mathScore=%.2f, engScore=%.2f, cScore=%.2f }",s.mathScore,s.engScore,s.cScore];}
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