字节的不同单位间的转换
- (NSString *)fileSizeWithInterge:(NSInteger)size { // 1k = 1024, 1m = 1024k if (size < 1024) {// 小于1k return [NSString stringWithFormat:@"%ldB",(long)size]; }else if (size < 1024 * 1024){// 小于1m CGFloat aFloat = size/1024; return [NSString stringWithFormat:@"%.0fKB",aFloat]; }else if (size < 1024 * 1024 * 1024){// 小于1G CGFloat aFloat = size/(1024 * 1024); return [NSString stringWithFormat:@"%.1fM",aFloat]; }else { CGFloat aFloat = size/(1024*1024*1024); return [NSString stringWithFormat:@"%.1fG",aFloat]; } }