ios 编码转换 保存文件

- (NSString *)SaveFileToDocuments:(NSString *)url

{

// NSString *url = @"http://172.28.250.70/ad/20140210151602.jpg";

NSString *FileName = [url lastPathComponent];

NSString *resultFilePath = @"";

if (url.length > 7) {

NSString *destFolderPath = [[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:@"IadImages"];

NSString *destFilePath = [destFolderPath stringByAppendingPathComponent:url];

if (! [[NSFileManager defaultManager] fileExistsAtPath:destFolderPath]) { //判断文件夹是否存在

[[NSFileManagerdefaultManager] createDirectoryAtPath:destFolderPath withIntermediateDirectories:YESattributes:nilerror:nil];

}

if ([[NSFileManager defaultManager] fileExistsAtPath:destFilePath]) { //判断文件是否存在

resultFilePath = destFilePath;

} else {

NSData *imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:url]];

if ([imageData writeToFile:destFilePath atomically:YES]) {

resultFilePath = destFilePath;

}

else {

resultFilePath = destFilePath;

}

}

}

return resultFilePath;

}

- (NSString*)UTF8_To_GB2312:(NSString*)utf8string

{

NSStringEncoding encoding =CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_18030_2000);

NSData* gb2312data = [utf8string dataUsingEncoding:encoding];

return [[NSString alloc] initWithData:gb2312data encoding:encoding];

}