iOS常用字符串的操作技巧.doc

iOS常用字符串的操作 //将NSData转化为NSString?? ??? ?NSString* str = [[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding];//将NSString 转化为NSData (NSString.h)- (NSData *)dataUsingEncoding:(NSStringEncoding)encoding; ??//载一个字符串中删除一个字符或字符串[_display deleteCharactersInRange:NSMakeRange(index_of_char_to_remove, 1)];数学转换为字符串NSString *returnStr;returnStr = [[NSNumber numberWithInt:row] stringValue];?? ? NSString ??? ? *******************************************************************************************/ ??? ?//一、NSString???? ??? ?/*----------------创建字符串的方法----------------*/ ??? ? ??? ?//1、创建常量字符串。 ??? ?NSString *astring = @This is a String!; ??? ? ??? ? ??? ?//2、创建空字符串，给予赋值。 ??? ? ??? ?NSString *astring = [[NSString alloc] init]; ??? ?astring = @This is a String!; ??? ?[astring release]; ??? ?NSLog(@astring:%@,astring); ??? ? ??? ? ??? ? ??? ?//3、在以上方法中，提升速度:initWithString方法 ??? ? ??? ?NSString *astring = [[NSString alloc] initWithString:@This is a String!]; ??? ?NSLog(@astring:%@,astring); ??? ?[astring release]; ??? ? ??? ? ??? ? ??? ?//4、用标准c创建字符串:initWithCString方法 ??? ? ??? ?char *Cstring = This is a String!; ??? ?NSString *astring = [[NSString alloc] initWithCString:Cstring]; ??? ?NSLog(@astring:%@,astring); ??? ?[astring release]; ??? ? ??? ? ??? ? ??? ?//5、创建格式化字符串:占位符（由一个%加一个字符组成） ??? ? ??? ?int i = 1; ??? ?int j = 2; ??? ?NSString *astring = [[NSString alloc] initWithString:[NSString stringWithFormat:@%d.This is %i string!,i,j]]; ??? ?NSLog(@astring:%@,astring); ??? ?[astring release]; ??? ? ??? ? ??? ? ??? ?//6、创建临时字符串 ??? ? ??? ?NSString *astring; ??? ?astring = [NSString stringWithCString:This is a temporary string]; ??? ?NSLog(@astring:%@,astring); ??? ? ??? ? ??? ? ??? ? ??? ?/*----------------从文件读取字符串:initWithContentsOfFile方法----------------*/???? ??? ? ??? ?NSString *path = @astring.text; ??? ?NSString *astring = [[NSString alloc] initWithContentsOfFile:path]; ??? ?NSLog(@a