如何以PDF格式获取UITableView的快照

Question

我有一个UITableView填充了一些数据,但由于它包含的数据比屏幕的可视区域更多的单元格,我只能设法得到它的快照,我想知道是否有其他方法我可以获得整个tableview快照在pdf ..这是我尝试过的感谢

- (IBAction)clickMe:(id)sender
{
    UIView *viewToRender = self.myTableView;
    CGPoint contentOffset = self.myTableView.contentOffset;

    UIGraphicsBeginImageContext(viewToRender.bounds.size);

    CGContextRef ctx = UIGraphicsGetCurrentContext();

    //  KEY: need to translate the context down to the current visible portion of the tablview
    CGContextTranslateCTM(ctx, 0, -contentOffset.y);

    [viewToRender.layer renderInContext:ctx];

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIImageView *myImage=[[UIImageView alloc]initWithImage:image];

    UIGraphicsEndImageContext();

    [self createPDFfromUIViews:myImage saveToDocumentsWithFileName:@"PDF Name"];

}



- (void)createPDFfromUIViews:(UIView *)myImage saveToDocumentsWithFileName:(NSString *)string
{
    NSMutableData *pdfData = [NSMutableData data];

    UIGraphicsBeginPDFContextToData(pdfData, myImage.bounds, nil);
    UIGraphicsBeginPDFPage();
    CGContextRef pdfContext = UIGraphicsGetCurrentContext();


    // draws rect to the view and thus this is captured by UIGraphicsBeginPDFContextToData

    [myImage.layer renderInContext:pdfContext];

    // remove PDF rendering context
    UIGraphicsEndPDFContext();
    NSArray* documentDirectories = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES);

    NSString* documentDirectory = [documentDirectories objectAtIndex:0];
    NSString* documentDirectoryFilename = [documentDirectory stringByAppendingPathComponent:string];

    NSLog(@"%@",documentDirectoryFilename);
    [pdfData writeToFile:documentDirectoryFilename atomically:YES];
}

Answer 1

UIGraphicsBeginImageContext(self.myTableView.contentSize);
[self.myTableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:0] atScrollPosition:UITableViewScrollPositionTop animated:NO];
[self.myTableView.layer renderInContext:UIGraphicsGetCurrentContext()];

int rows = [self.myTableView numberOfRowsInSection:0];
int numberofRowsInView = 4;
for (int i =0; i < rows/numberofRowsInView; i++) {
    [self.myTableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:(i+1)*numberofRowsInView inSection:0] atScrollPosition:UITableViewScrollPositionTop animated:NO];
    [self.myTableView.layer renderInContext:UIGraphicsGetCurrentContext()];

}
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIImageView *myImage=[[UIImageView alloc]initWithImage:image];
UIGraphicsEndImageContext();


[self createPDFfromUIViews:myImage saveToDocumentsWithFileName:@"PDF Name"];

我不知道,但这段代码对我来说就像一个魅力..

Answer 2

这是你如何在不滚动tableview的情况下完成的.只需将scrollview的高度增加到contentSize即可.如果你不经过,PDF的质量也会更好UIImage.这是我UITableView在Swift中的扩展.代码是从这里和那里偷来的所以评论并不总是我的.

func toPDF(fileName: String) -> String {
    // Don't include scroll indicators in file
    self.showsVerticalScrollIndicator = false

    // Creates a mutable data object for updating with binary data, like a byte array
    let pdfData = NSMutableData()

    // Change the frame size to include all data
    let originalFrame = self.frame
    self.frame = CGRectMake(self.frame.origin.x, self.frame.origin.y, self.contentSize.width, self.contentSize.height)

    // Points the pdf converter to the mutable data object and to the UIView to be converted
    UIGraphicsBeginPDFContextToData(pdfData, self.bounds, nil)
    UIGraphicsBeginPDFPage()
    let pdfContext = UIGraphicsGetCurrentContext();

    // Draws rect to the view and thus this is captured by UIGraphicsBeginPDFContextToData
    self.layer.renderInContext(pdfContext!)

    // Remove PDF rendering context
    UIGraphicsEndPDFContext()

    // Retrieves the document directories from the iOS device
    let documentDirectories: NSArray = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)

    let documentDirectory = documentDirectories.objectAtIndex(0)
    let documentDirectoryFilename = documentDirectory.stringByAppendingPathComponent(fileName);

    // Instructs the mutable data object to write its context to a file on disk
    pdfData.writeToFile(documentDirectoryFilename, atomically: true)

    // Back to normal size
    self.frame = originalFrame

    // Put back the scroll indicator
    self.showsVerticalScrollIndicator = true

    return documentDirectoryFilename
}