UIImage自适應UIImageView的frame大小

UIImage* tempImage = [UIImage imageWithContentsOfFile:tempPath];

UIImageView* tempImageView = [[UIImageView alloc] initWithImage:tempImage];

tempImageView.frame = frame;

tempImageView.contentMode = UIViewContentModeScaleAspectFit;//最關鍵的一條語句

[self.view addSubview:tempImageView];