我有一个非常奇怪和特殊的情况，我想在屏幕上显示 PDF。但是，问题是我的文档显示模糊的线条，而不是在 Acrobat Pro 程序中显示。
看这张图片：
这是我可以用 CGContext 修复（模糊的线条）还是分辨率问题。这是我的代码：
- (id)initWithFrame:(CGRect)frame {
self = [super initWithFrame:(CGRect)frame];
if (self) {
self.backgroundColor = [UIColor clearColor];
NSString *pathToPdfDoc = [[NSBundle mainBundle] pathForResource:@"myPDF" ofType:@"pdf"];
NSURL *pdfUrl = [NSURL fileURLWithPath:pathToPdfDoc];
document = CGPDFDocumentCreateWithURL((__bridge CFURLRef)pdfUrl);
currentPage = 1;
}
return self;
}
+ (void) renderPage: (CGPDFPageRef) page inContext: (CGContextRef) context{
[viewPDF renderPage:page inContext:context atPoint:CGPointMake(0, 0)];
}
+ (void) renderPage: (CGPDFPageRef) page inContext: (CGContextRef) context atPoint:(CGPoint) point{
[viewPDF renderPage:page inContext:context atPoint:point withZoom:100];
}
+ (void) renderPage: (CGPDFPageRef) page inContext: (CGContextRef) context atPoint: (CGPoint) point withZoom: (float) zoom{
CGRect cropBox = CGPDFPageGetBoxRect(page, kCGPDFCropBox);
int rotate = CGPDFPageGetRotationAngle(page);
CGContextSaveGState(context);
// Setup the coordinate system.
// Top left corner of the displayed page must be located at the point specified by the 'point' parameter.
CGContextTranslateCTM(context, point.x, point.y);
// Scale the page to desired zoom level.
CGContextScaleCTM(context, zoom / 100, zoom / 100);
// The coordinate system must be set to match the PDF coordinate system.
switch (rotate) {
case 0:
CGContextTranslateCTM(context, 0, cropBox.size.height);
CGContextScaleCTM(context, 1, -1);
break;
case 90:
CGContextScaleCTM(context, 1, -1);
CGContextRotateCTM(context, -M_PI / 2);
break;
case 180:
case -180:
CGContextScaleCTM(context, 1, -1);
CGContextTranslateCTM(context, cropBox.size.width, 0);
CGContextRotateCTM(context, M_PI);
break;
case 270:
case -90:
CGContextTranslateCTM(context, cropBox.size.height, cropBox.size.width);
CGContextRotateCTM(context, M_PI / 2);
CGContextScaleCTM(context, -1, 1);
break;
}
// The CropBox defines the page visible area, clip everything outside it.
CGRect clipRect = CGRectMake(0, 0, cropBox.size.width, cropBox.size.height);
CGContextAddRect(context, clipRect);
CGContextClip(context);
CGContextSetRGBFillColor(context, 1.0, 1.0, 1.0, 1.0);
CGContextSetLineJoin(context, kCGLineJoinRound);
CGContextFillRect(context, clipRect);
CGContextTranslateCTM(context, -cropBox.origin.x, -cropBox.origin.y);
CGContextDrawPDFPage(context, page);
CGContextRestoreGState(context);
}
+ (void) renderPage: (CGPDFPageRef) page inContext: (CGContextRef) context inRectangle: (CGRect) displayRectangle {
if ((displayRectangle.size.width == 0) || (displayRectangle.size.height == 0)) {
return;
}
CGRect cropBox = CGPDFPageGetBoxRect(page, kCGPDFCropBox);
int pageRotation = CGPDFPageGetRotationAngle(page);
CGSize pageVisibleSize = CGSizeMake(cropBox.size.width, cropBox.size.height);
if ((pageRotation == 90) || (pageRotation == 270) ||(pageRotation == -90)) {
pageVisibleSize = CGSizeMake(cropBox.size.height, cropBox.size.width);
}
float scaleX = displayRectangle.size.width / pageVisibleSize.width;
float scaleY = displayRectangle.size.height / pageVisibleSize.height;
float scale = scaleX < scaleY ? scaleX : scaleY;
// Offset relative to top left corner of rectangle where the page will be displayed
float offsetX = 0;
float offsetY = 0;
float rectangleAspectRatio = displayRectangle.size.width / displayRectangle.size.height;
float pageAspectRatio = pageVisibleSize.width / pageVisibleSize.height;
if (pageAspectRatio < rectangleAspectRatio) {
// The page is narrower than the rectangle, we place it at center on the horizontal
offsetX = (displayRectangle.size.width - pageVisibleSize.width * scale) / 2;
}
else {
// The page is wider than the rectangle, we place it at center on the vertical
offsetY = (displayRectangle.size.height - pageVisibleSize.height * scale) / 2;
}
CGPoint topLeftPage = CGPointMake(displayRectangle.origin.x + offsetX, displayRectangle.origin.y + offsetY);
[viewPDF renderPage:page inContext:context atPoint:topLeftPage withZoom:scale * 100];
}
-(void)drawRect:(CGRect)inRect{
if(document)
{
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGPDFPageRef page = CGPDFDocumentGetPage(document, currentPage);
[viewPDF renderPage:page inContext:ctx atPoint:CGPointMake(10,10) withZoom:125];
}