1，首先二维码生成
//生成二维码
CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
// 2.过滤器恢复默认设置
[filter setDefaults];
// 3.给过滤器添加数据(正则表达式/帐号和密码) -- 通过KVC设置过滤器,只能设置NSData类型
NSString *dataString = @"http://www.baidu.com";
NSData *data = [dataString dataUsingEncoding:NSUTF8StringEncoding];
[filter setValue:data forKeyPath:@"inputMessage"];
// 4.获取输出的二维码
CIImage *outputImage = [filter outputImage];
// 5.显示二维码
UIImageView *erweimaImageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 250, 250)];
2 截屏，并保存一下
CGRect rect = CGRectMake(0, 0, XHW_W , XHW_H);
UIGraphicsBeginImageContext(rect.size);
CGContextRef context = UIGraphicsGetCurrentContext();
[self.view.layer renderInContext:context];
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
_mergeImage = img;
[_TopimageView setImage:img];
3，拼接截屏的图片和二维码
//合并多张图片(不缩小,原大小)
- (UIImage *)composeWithHeader:(UIImage *)header footer:(UIImage *)footer{
CGSize size = CGSizeMake(header.size.width, (header.size.height) + (88));
//UIGraphicsBeginImageContextWithOptions(<#CGSize size#>, BOOL opaque, CGFloat scale)
UIGraphicsBeginImageContextWithOptions(size, YES, 0.0);
CGContextRef context = UIGraphicsGetCurrentContext();
//CGContextSetFillColorWithColor(<#CGContextRef _Nullable c#>, <#CGColorRef _Nullable color#>)
CGContextSetFillColorWithColor(context, [UIColor colorWithPatternImage:[UIImage imageNamed:@"WechatIMG1 2"]].CGColor);//在这段上下文中获取到颜色UIColor
CGContextFillRect(context, CGRectMake(0, 0, size.width, size.height));
//用这个颜色填充这个上下文
[header drawInRect:CGRectMake(0, 0, header.size.width, header.size.height)];
[footer drawInRect:CGRectMake(0, header.size.height - 150 , (100), (100))];
//[self drawText:context frame:CGRectMake(0, 0, size.width, size.height)];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}