UIImageView*imageView = [[UIImageViewalloc]initWithFrame:CGRectMake(50,50,100,100)];
imageView.image= [UIImageimageNamed:@"11"];
//png格式
NSData*imagedata=UIImagePNGRepresentation(imageView.image);
//JEPG格式
//NSData *imagedata=UIImageJEPGRepresentation(m_imgFore,1.0);
NSArray*paths=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
NSString*documentsDirectory=[pathsobjectAtIndex:0];
NSString*savedImagePath=[documentsDirectorystringByAppendingPathComponent:@"11.png"];
[imagedatawriteToFile:savedImagePathatomically:YES];