IOS wkwebview保存长图
方案1：
UIImage* image = nil;
// 下面方法，第一个参数表示区域大小。第二个参数表示是否是非透明的。如果需要显示半透明效果，需要传NO，否则传YES。第三个参数就是屏幕密度了，调整清晰度。
UIGraphicsBeginImageContextWithOptions(self.wkWebView.scrollView.contentSize, YES, [UIScreen mainScreen].scale);
CGPoint savedContentOffset = self.wkWebView.scrollView.contentOffset;
CGRect savedFrame = self.wkWebView.frame;
self.wkWebView.scrollView.contentOffset = CGPointZero;
self.wkWebView.frame = CGRectMake(0, 0, self.wkWebView.scrollView.contentSize.width, self.wkWebView.scrollView.contentSize.height);
[self.wkWebView.layer renderInContext: UIGraphicsGetCurrentContext()];
image = UIGraphicsGetImageFromCurrentImageContext();
self.wkWebView.scrollView.contentOffset = savedContentOffset;
self.wkWebView.frame = savedFrame;
UIGraphicsEndImageContext();
if (image != nil) {
//保存图片到相册
UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSavingWithError:contextInfo:), NULL);
}
方案2：
ZYCaptureScreenShotView *captureView = [[ZYCaptureScreenShotView alloc]initWithFormatter:self.wkWebView.viewPrintFormatter andContentSize:self.wkWebView.scrollView.contentSize];
UIImage *image = [captureView getContentImage];
if (image != nil) {
//保存图片到相册
UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSavingWithError:contextInfo:), NULL);
}
方案3：
CGPoint originalOffset = self.wkWebView.scrollView.contentOffset;
// 当contentSize.height
NSInteger pageNum = 1;
if (self.wkWebView.scrollView.contentSize.height > self.wkWebView.bounds.size.height) {
pageNum = (NSInteger)(floorf((self.wkWebView.scrollView.contentSize.height / self.wkWebView.bounds.size.height)));
}
UIGraphicsBeginImageContextWithOptions(self.wkWebView.scrollView.contentSize, true, 0);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context, [UIColor whiteColor].CGColor);
CGContextSetStrokeColorWithColor(context, [UIColor whiteColor].CGColor);
[self drawImagePageIndex:0 maxIndex:pageNum complet:^(BOOL complet) {
if (complet) {
UIImage *image =UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
self.wkWebView.scrollView.contentOffset = originalOffset;
if (image != nil) {
//保存图片到相册
UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSavingWithError:contextInfo:), NULL);
}
}
}];
- (void)drawImagePageIndex:(NSInteger)index maxIndex:(NSInteger)maxIndex complet:(void (^)(BOOL complet))block
{
[self.wkWebView.scrollView setContentOffset:CGPointMake(0, (CGFloat)index * self.wkWebView.bounds.size.height) animated:YES];
CGRect pageFrame = CGRectMake(0, (CGFloat)index * self.wkWebView.bounds.size.height, self.wkWebView.bounds.size.width, self.wkWebView.bounds.size.height);
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 0.3 * NSEC_PER_SEC), dispatch_get_main_queue(), ^{
[self.wkWebView drawViewHierarchyInRect:pageFrame afterScreenUpdates:YES];
if (index < maxIndex) {
[self drawImagePageIndex:index + 1 maxIndex:maxIndex complet:block];
} else {
block(YES);
}
});
}
方案4：
if (@available(iOS 11.0, *)) {
WKSnapshotConfiguration *confige = [WKSnapshotConfiguration new];
confige.rect = CGRectMake(0, 0, self.wkWebView.scrollView.contentSize.width, self.wkWebView.scrollView.contentSize.height);
confige.snapshotWidth = [NSNumber numberWithFloat:self.wkWebView.scrollView.contentSize.width / [UIScreen mainScreen].scale];
[self.wkWebView takeSnapshotWithConfiguration:confige completionHandler:^(UIImage *_Nullable snapshotImage, NSError *_Nullable error) {
if (snapshotImage != nil) {
//保存图片到相册
UIImageWriteToSavedPhotosAlbum(snapshotImage, self, @selector(image:didFinishSavingWithError:contextInfo:), NULL);
}
}];
} else {
// Fallback on earlier versions
}
- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo
{
if (image) {
NSString *msg = nil;
if (error != NULL) {
msg = @"保存图片失败";
} else {
msg = @"保存图片成功，可到相册查看";
}
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"信息提示"
message:msg
delegate:self
cancelButtonTitle:@"确定"
otherButtonTitles:nil];
[alert show];
}
}
用到的类的代码如下
@interface ZYCaptureScreenShotView : UIPrintPageRenderer
-(instancetype)initWithFormatter:(UIPrintFormatter*)formatter andContentSize:(CGSize)contentSize;
-(UIImage*)getContentImage;
@end
@interface ZYCaptureScreenShotView ()
@property (nonatomic, strong) UIPrintFormatter *formatter;
@property (nonatomic, assign) CGSize contentSize;
@end
@implementation ZYCaptureScreenShotView
- (instancetype)initWithFormatter:(UIPrintFormatter *)formatter andContentSize:(CGSize)contentSize
{
if (self = [super init]) {
self.formatter = formatter;
self.contentSize = contentSize;
[self addPrintFormatter:formatter startingAtPageAtIndex:0];
}
return self;
}
- (CGRect)paperRect
{
return CGRectMake(0, 0, self.contentSize.width, self.contentSize.height);
}
- (CGRect)printableRect
{
return CGRectMake(0, 0, self.contentSize.width, self.contentSize.height);
}
- (CGPDFPageRef)printContentToPDF
{
NSMutableData *data = [NSMutableData data];
UIGraphicsBeginPDFContextToData(data, self.paperRect, nil);
[self prepareForDrawingPages:NSMakeRange(0, 1)];
CGRect bounds = UIGraphicsGetPDFContextBounds();
UIGraphicsBeginPDFPage();
[self drawContentForPageAtIndex:0 inRect:bounds];
UIGraphicsEndPDFContext();
CGDataProviderRef provider = CGDataProviderCreateWithCFData(CFBridgingRetain(data));
CGPDFDocumentRef document = CGPDFDocumentCreateWithProvider(provider);
return CGPDFDocumentGetPage(document, 1);
}
- (UIImage *)convertPDFPageToImage:(CGPDFPageRef)pdfPage
{
CGRect pageRect = CGPDFPageGetBoxRect(pdfPage, kCGPDFTrimBox);
CGSize contentSize = CGSizeMake(floor(pageRect.size.width), floor(pageRect.size.height));
UIGraphicsBeginImageContextWithOptions(contentSize, true, 2.0);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context, [UIColor whiteColor].CGColor);
CGContextSetStrokeColorWithColor(context, [UIColor whiteColor].CGColor);
CGContextFillRect(context, pageRect);
CGContextSaveGState(context);
CGContextTranslateCTM(context, 0, contentSize.height);
CGContextScaleCTM(context, 1.0, -1.0);
CGContextSetInterpolationQuality(context, kCGInterpolationLow);
CGContextSetRenderingIntent(context, kCGRenderingIntentDefault);
CGContextDrawPDFPage(context, pdfPage);
CGContextRestoreGState(context);
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
- (UIImage *)getContentImage
{
UIImage *image;
if ([self printContentToPDF]) {
image = [self convertPDFPageToImage:[self printContentToPDF]];
}
return image;
}
@end
@interface WKWebView (ZYToFile)
- (UIImage *)imageRepresentation;
- (NSData *)PDFData;
@end
#import
@implementation WKWebView (ZYToFile)
- (UIImage *)imageRepresentation{
CGFloat scale = [UIScreen mainScreen].scale;
CGSize boundsSize = self.bounds.size;
CGFloat boundsWidth = boundsSize.width;
CGFloat boundsHeight = boundsSize.height;
CGSize contentSize = self.scrollView.contentSize;
CGFloat contentHeight = contentSize.height;
CGPoint offset = self.scrollView.contentOffset;
[self.scrollView setContentOffset:CGPointMake(0, 0)];
NSMutableArray *images = [NSMutableArray array];
while (contentHeight > 0) {
UIGraphicsBeginImageContextWithOptions(boundsSize, NO, 0.0);
[self.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
[images addObject:image];
CGFloat offsetY = self.scrollView.contentOffset.y;
[self.scrollView setContentOffset:CGPointMake(0, offsetY + boundsHeight)];
contentHeight -= boundsHeight;
}
[self.scrollView setContentOffset:offset];
CGSize imageSize = CGSizeMake(contentSize.width * scale,
contentSize.height * scale);
UIGraphicsBeginImageContext(imageSize);
[images enumerateObjectsUsingBlock:^(UIImage *image, NSUInteger idx, BOOL *stop) {
[image drawInRect:CGRectMake(0,
scale * boundsHeight * idx,
scale * boundsWidth,
scale * boundsHeight)];
}];
UIImage *fullImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return fullImage;
}
- (NSData *)PDFData{
UIViewPrintFormatter *fmt = [self viewPrintFormatter];
UIPrintPageRenderer *render = [[UIPrintPageRenderer alloc] init];
[render addPrintFormatter:fmt startingAtPageAtIndex:0];
CGRect page;
page.origin.x=0;
page.origin.y=0;
page.size.width=600;
page.size.height=768;
CGRect printable=CGRectInset( page, 50, 50 );
[render setValue:[NSValue valueWithCGRect:page] forKey:@"paperRect"];
[render setValue:[NSValue valueWithCGRect:printable] forKey:@"printableRect"];
NSMutableData * pdfData = [NSMutableData data];
UIGraphicsBeginPDFContextToData( pdfData, CGRectZero, nil );
for (NSInteger i=0; i < [render numberOfPages]; i++)
{
UIGraphicsBeginPDFPage();
CGRect bounds = UIGraphicsGetPDFContextBounds();
[render drawPageAtIndex:i inRect:bounds];
}
UIGraphicsEndPDFContext();
return pdfData;
}
@end
总结
经过多次测试，只有方案4最靠谱，能截到完整的长图。前三个都有问题，以上方案大部分来自互联网。