我正在尝试使用 PDF 文件(包含带有多个“记录”的表格的表格)作为模板。我的想法是将原始文件作为模板读取,然后使用Swifts绘图功能在相关位置插入文本,然后保存为新的pdf文件并打印。
我的问题是,在重新保存输出时,我看到分辨率略有下降(字体有点毛茸茸,网格线不再清晰)。
我尝试了两种方法,第一种将我的“模板”作为项目中的文件,第二种将其作为资产(比例:单一比例,调整大小:保留矢量数据)。
这是我的代码:
func createCompletedForm(records: [MyDataObject]) -> URL? {
let directoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
let fileURL = URL(fileURLWithPath: "pdfToPrint", relativeTo: directoryURL).appendingPathExtension("pdf")
guard let templateUrl = Bundle.main.url(forResource: "MyPdfTemplate", withExtension: "pdf") else { return nil }
guard let document = CGPDFDocument(templateUrl as CFURL) else { return nil }
guard let page = document.page(at: 1) else { return nil }
let pageTemplate = page.getBoxRect(.mediaBox)
UIGraphicsBeginPDFContextToFile(fileURL.path, pageTemplate, nil)
guard let pdfContext = UIGraphicsGetCurrentContext() else {
print("Unable to access PDF Context.")
return nil
}
// Mark the beginning of the page.
pdfContext.beginPDFPage(nil)
// Save the context state to restore after we are done drawing the image.
pdfContext.saveGState()
// Change the PDF context to match the UIKit coordinate system.
pdfContext.translateBy(x: 0, y: StandardPageDimensions.ISO216_A4.height)
pdfContext.scaleBy(x: 1, y: -1)
// Option 1: Draw PDF from a file added to my project
DrawingHelper.drawPDFfromCGPDF(page: page, drawingArea: pageTemplate)
// Option 2: Draw PDF from Assets
//let baseTemplate = UIImage(named: "MyPdfTemplate")
//baseTemplate?.draw(at: CGPoint(x: 0, y: 0))
// Draw the records over the template - NOT the source of the problem, happens even when commented out
//addRecordsToTemplate(records: records)
// Restoring the context back to its original state.
pdfContext.restoreGState()
// Mark the end of the current page.
pdfContext.endPDFPage()
UIGraphicsEndPDFContext()
// Useful to find and open the file produced on the simulator
print("pdf created at : \(fileURL.path)")
return fileURL
}
// And the drawing function from my helper class
static func drawPDFfromCGPDF(page: CGPDFPage, drawingArea: CGRect) {
let renderer = UIGraphicsImageRenderer(size: drawingArea.size)
let img = renderer.image { ctx in
UIColor.white.set()
ctx.fill(drawingArea)
ctx.cgContext.translateBy(x: 0.0, y: drawingArea.size.height)
ctx.cgContext.scaleBy(x: 1.0, y: -1.0)
ctx.cgContext.drawPDFPage(page)
}
img.draw(at: CGPoint(x: 0, y: 0))
}