view 转为image 清晰度不变

-(UIImage *)getImageFromView:(UIView *)theView

{

    //scale 为2可以改为2倍图的清晰度，plus可以改为3，

float scale = 2;

    UIGraphicsBeginImageContextWithOptions(theView.bounds.size,
YES, scale);

    [theView.layer
renderInContext:UIGraphicsGetCurrentContext()];

    UIImage *image=UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return image;

}