IOS UIImage,NSString,NSData的相互转换

2017-08-19 本文已影响16人小暖风

数据转换

NSData -->UIImage

[UIImage imageWithData:<#(NSData *)#>];

UIImage --> NSData

NSData * data = UIImagePNGRepresentation(_imageView.image);

NSData --> NSString

NSString * string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

NSString --> NSData

NSData * data = [@"aaa" dataUsingEncoding:NSUTF8StringEncoding];

汉字转换成电脑能是别的码

[@"甄嬛传" stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

//通过fileManager获取到指定路径下文件的所有属性，得到一个字典

NSDictionary *attDic = [[NSFileManager defaultManager] attributesOfItemAtPath:path error:nil];

文件写入写出常用函数

-(BOOL)writeToFile:(NSString *)path atomically:(BOOL)flag;

-(id)initWithContentsOfFile:(NSString *)path;

如果文件中内容少的用NSUserDefaults，多的也可用SOL或者XML。

获取文件创建时间和大小的代码

NSDictionary *fileAttributes = [[NSFileManager defaultManager] fileAttributesAtPath:path traverseLink:YES]；

image png,jpg格式判断

image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];

NSData *data;

if (UIImagePNGRepresentation(image) == nil) {

data = UIImageJPEGRepresentation(image, 1);

} else {

data = UIImagePNGRepresentation(image);

}