objective-c - Cocoa (Mac Os X) 打印多页，为什么预览窗口显示 2 页而不是 1 页？

Question

我有一个正在开发的 cocoa 应用程序，我在其中创建了一个要发送到打印机的 customView。在子类 NSView 中，我也设置了一些框架选项，代码如下。我有 2 个全局变量来保存在 main() 函数外声明的打印信息。

- (id)initWithFrame:(NSRect)frame
{
    extern NSPrintInfo *globalPrintInfo;
    extern NSPrintOperation *globalPrintOperation;

    //Modify the frame before it's sent to it's super method.  Also set the global variables to there default values.
    globalPrintOperation = [NSPrintOperation printOperationWithView:self];
    globalPrintInfo = [globalPrintOperation printInfo];//Get the print information from it.

    [globalPrintInfo setBottomMargin:0.0];
    [globalPrintInfo setLeftMargin:0.0];
    [globalPrintInfo setTopMargin:0.0];
    [globalPrintInfo setRightMargin:0.0];

    [globalPrintOperation setPrintInfo:globalPrintInfo];//save the printInfo changes.

    //modify the frame to reflect the correct height & width of the paper.
    frame.size.height = globalPrintInfo.paperSize.height-globalPrintInfo.topMargin-globalPrintInfo.bottomMargin;
    frame.size.width = globalPrintInfo.paperSize.width-globalPrintInfo.leftMargin-globalPrintInfo.rightMargin;
    frame.origin.x=0;
    frame.origin.y=0;

    NSLog(@"Printer Name=%@, Printer Type=%@",globalPrintInfo.printer.name,globalPrintInfo.printer.type);

    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code here.

    }

    return self;
}

对于子类化的 NSView，以便我可以看到它的边界，我在下面的 drawRect 方法中添加了以下代码。

- (void)drawRect:(NSRect)dirtyRect
{
    if ( [NSGraphicsContext currentContextDrawingToScreen] ) {
        NSLog(@"Drawing To Screen");
    } else {
        NSLog(@"Drawing To Printer");
    }

    // Draw common elements here

    CGContextRef myContext = [[NSGraphicsContext currentContext] graphicsPort];

    //Set color of drawing to green, and fill the rectangle green, so we can see it's boundaries.
    [[NSColor greenColor] setFill];
    NSRectFill(dirtyRect);

    CGContextSelectFont(myContext, "Helvetica-Bold", 18, kCGEncodingMacRoman);
    CGContextSetCharacterSpacing(myContext, 10);
    CGContextSetTextDrawingMode(myContext, kCGTextFillStroke);

    CGContextSetRGBFillColor(myContext, 0, 0, 0, 1);//black
    CGContextSetRGBStrokeColor (myContext, 0, 0, 1, 1);//blue stroke
    CGContextShowTextAtPoint(myContext, 40, 0, "Here is some text!", 18);

}

当我使用全局变量运行打印操作时，就像这样......

- (IBAction)print:(id)sender {
    NSLog(@"Testing Print");

    extern NSPrintOperation *globalPrintOperation;

    [globalPrintOperation runOperation];
}

我让打印窗口出现，我看到了我的 View 的“绿色背景”，但由于某种原因它被分成了 2 页。当我将框架的宽度和高度设置为 pagesize.width & height 时，我不确定到底发生了什么，感谢您的帮助。下面是我看到的一些图片。

我的猜测是页面大小宽度和高度的单位与用于定义 View 框架的像素单位类型不同。

我的最终目标是制作一个程序，用户可以在其中选择他们想要的内容，并根据他们选择的选项打印特定页面，但首先我必须弄清楚如何将我期望的“内容”添加到 '1 ' 页而不是 '2'。我可以通过实验手动计算出宽度和高度，但对于我假设的不同纸张尺寸，这不会非常动态。

提前致谢。

编辑***

我刚刚为子类 NSVIEW 将我的代码编辑为以下内容

//METHOD OVERIDES
- (id)initWithFrame:(NSRect)frame
{
    extern NSPrintInfo *globalPrintInfo;
    extern NSPrintOperation *globalPrintOperation;

    //Modify the frame before it's sent to it's super method.  Also set the global variables to there default values.
    globalPrintOperation = [NSPrintOperation printOperationWithView:self];//use whatever is currently there as the default print operation.
    globalPrintInfo = [globalPrintOperation printInfo];//Get the print information from it.

    [globalPrintInfo setBottomMargin:0.0];
    [globalPrintInfo setLeftMargin:0.0];
    [globalPrintInfo setTopMargin:0.0];
    [globalPrintInfo setRightMargin:0.0];

    [globalPrintOperation setPrintInfo:globalPrintInfo];//save the printInfo changes.

    //modify the frame to reflect the correct height & width of the paper.
    frame.size.height = (globalPrintInfo.paperSize.height-globalPrintInfo.topMargin-globalPrintInfo.bottomMargin);
    frame.size.width = globalPrintInfo.paperSize.width-globalPrintInfo.leftMargin-globalPrintInfo.rightMargin;
    frame.origin.x=0;
    frame.origin.y=0;

    NSLog(@"Printer Name=%@, Printer Type=%@",globalPrintInfo.printer.name,globalPrintInfo.printer.type);

    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code here.

    }

    return self;
}

- (void)drawRect:(NSRect)dirtyRect
{
    if ( [NSGraphicsContext currentContextDrawingToScreen] ) {
        NSLog(@"Drawing To Screen");
    } else {
        NSLog(@"Drawing To Printer");
    }

    // Draw common elements here

    CGContextRef myContext = [[NSGraphicsContext currentContext] graphicsPort];

    //Set color of drawing to green, and fill the rectangle green, so we can see it's boundaries.
    [[NSColor greenColor] setFill];
    NSRectFill(dirtyRect);

    CGContextSelectFont(myContext, "Helvetica-Bold", 18, kCGEncodingMacRoman);
    CGContextSetCharacterSpacing(myContext, 10);
    CGContextSetTextDrawingMode(myContext, kCGTextFillStroke);

    CGContextSetRGBFillColor(myContext, 0, 0, 0, 1);//black
    CGContextSetRGBStrokeColor (myContext, 0, 0, 1, 1);//blue stroke
    CGContextShowTextAtPoint(myContext, 40, 0, "Here is some text!", 18);

}


- (BOOL)knowsPageRange:(NSRangePointer)range {
    NSRect bounds = [self bounds];
    float printHeight = [self calculatePrintHeight];

    range->location = 1;
    range->length = NSHeight(bounds) / printHeight + 1;

    NSLog(@"Calculated Page Range");
    return YES;
}

// Return the drawing rectangle for a particular page number
- (NSRect)rectForPage:(int)page {
    NSRect bounds = [self bounds];
    float pageHeight = [self calculatePrintHeight];
    NSLog(@"Created Rect For View");
    return NSMakeRect( NSMinX(bounds), NSMaxY(bounds) - page * pageHeight,
                      NSWidth(bounds), pageHeight );
}

//CUSTOM METHODS

// Calculate the vertical size of the view that fits on a single page
- (float)calculatePrintHeight {

    extern NSPrintInfo *globalPrintInfo;
    extern NSPrintOperation *globalPrintOperation;

    // Obtain the print info object for the current operation

    // Calculate the page height in points
    NSSize paperSize = [globalPrintInfo paperSize];
    float pageHeight = paperSize.height - [globalPrintInfo topMargin] - [globalPrintInfo bottomMargin];

    // Convert height to the scaled view
    float scale = [[[globalPrintInfo dictionary] objectForKey:NSPrintScalingFactor]
                   floatValue];

    NSLog(@"Calculated Print Height:%f",(pageHeight/scale));
    return (pageHeight / scale);
}

@end

我现在能够得到我想要的东西，接受当我去打印预览它仍然认为有第二页出于某种原因？现在不知道为什么。我会上传我看到的...

注意它是怎么说 1 of 2 的吗？不过，第二页只是空白。

Answer 1

所以我改进了我的打印类，使其对许多页面更加灵活，并希望共享代码。我在底部仍然有那个烦人的白色边框，我不太明白，但是当我去打印时它似乎不在那里？所以我需要一些帮助来解决这个问题，但除此之外，我设计了一个类，您只需向它发送一组 View ，它就会按照您收到的顺序打印 View 。

为此，我创建了 2 个类，PSPrint 和 PSPrintView。都是NSView的子类

这是 PSPrint.h 和 PSPrint.m 的代码

#import <Foundation/Foundation.h>
#import "PSPrintView.h"

@interface PSPrint : NSView
@property NSMutableArray *printViews;
@property (strong) NSPrintOperation *printOperation;
- (void)printTheViews;
@end

#import "PSPrint.h"
#import "PSPrintView.h"

@implementation PSPrint

- (id)initWithFrame:(NSRect)frame
{
    NSLog(@"Initializing Main PSPrintView");
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code here.
        _printViews = [[NSMutableArray alloc]initWithCapacity:1];//start it with capacity of 1
    }

    return self;
}

- (void)drawRect:(NSRect)dirtyRect{

}

- (BOOL)knowsPageRange:(NSRangePointer)range {
    NSRect bounds = [self bounds];
    float printHeight = [self calculatePrintHeight];

    range->location = 1;
    range->length = NSHeight(bounds) / printHeight + 0;

    NSLog(@"Calculated Page Range");
    return YES;
}

- (void)printTheViews{
    NSLog(@"Starting printTheViews Function of PSPrint");

    NSPrintInfo *sharedPrintInfo = [NSPrintInfo sharedPrintInfo];

    NSUInteger numOfViews = _printViews.count;

     NSLog(@"Creating %ld SubViews",numOfViews);

    NSUInteger totalHeight = 0;//if not initialized to 0 weird problems occur after '3' clicks to print, TODO: Find out why? Maybe because address space in memory not guaranteed to be 0 again?
    NSUInteger heightOfView = 0;
    PSPrintView *tempView;

    for (NSUInteger i=0; i<numOfViews; i++) {
        tempView = [_printViews objectAtIndex:i];
        heightOfView = tempView.frame.size.height;
        totalHeight = totalHeight + heightOfView;
    }

    //Change the frame size to reflect the amount of pages.
    NSSize newsize;
    newsize.width = sharedPrintInfo.paperSize.width-sharedPrintInfo.leftMargin-sharedPrintInfo.rightMargin;
    newsize.height = totalHeight;
    [self setFrameSize:newsize];

    NSLog(@"Total Height Of Main Print View Is %f",_frame.size.height);

    NSInteger incrementor=-1;//default the incrementor for the loop below.  This controls what page a 'view' will appear on.

    //Add the views in reverse, because the Y position is bottom not top.  So Page 3 will have y coordinate of 0.  Doing this so order views is placed in array reflects what is printed.
    for (NSInteger i=numOfViews-1; i>=0; i--) {
        incrementor++;
        tempView = [_printViews objectAtIndex:i];//starts with the last item added to the array, in this case rectangles, and then does circle and square.
        heightOfView = tempView.frame.size.height;

        NSPoint origin;
        origin.x = 0;
        origin.y = heightOfView*incrementor;//So for the rectangle it's placed at position '0', or the very last page.

        [tempView setFrameOrigin:origin];

        [self addSubview:tempView];
    }


    _printOperation = [NSPrintOperation printOperationWithView:self printInfo:sharedPrintInfo];
    [_printOperation runOperation];
}

// Return the drawing rectangle for a particular page number
- (NSRect)rectForPage:(int)page {
    NSRect bounds = [self bounds];
    float pageHeight = [self calculatePrintHeight];
    NSLog(@"Created Rect For View");
    return NSMakeRect( NSMinX(bounds), NSMaxY(bounds) - page * pageHeight,
                      NSWidth(bounds), pageHeight );
}

// Calculate the vertical size of the view that fits on a single page
- (float)calculatePrintHeight {

    NSPrintInfo *sharedPrintInfo = [NSPrintInfo sharedPrintInfo];

    // Obtain the print info object for the current operation

    // Calculate the page height in points
    NSSize paperSize = [sharedPrintInfo paperSize];
    float pageHeight = paperSize.height - [sharedPrintInfo topMargin] - [sharedPrintInfo bottomMargin];

    // Convert height to the scaled view
    float scale = [[[sharedPrintInfo dictionary] objectForKey:NSPrintScalingFactor]
                   floatValue];

    NSLog(@"Calculated Print Height:%f",(pageHeight/scale));
    return (pageHeight / scale);
}

@end

PSPrintView.h & PSPrintView.m 的代码如下

#import <Cocoa/Cocoa.h>

@interface PSPrintView : NSView
enum optionsForView{drawRectangle,drawCircle,drawSquare};
@property enum optionsForView myOptions;
- (void)drawSquare;
- (void)drawCircle;
- (void)drawRectangle;
@end


#import "PSPrintView.h"

@implementation PSPrintView

- (id)initWithFrame:(NSRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code here.
    }

    return self;
}

- (void)drawRect:(NSRect)dirtyRect
{
    NSLog(@"Drawing Green View Boundaries");
    NSPrintInfo *sharedPrintInfo = [NSPrintInfo sharedPrintInfo];

    //So we know the boundaries for the page. Remove in actual application.
    [[NSColor greenColor] setFill];
    NSRectFill(dirtyRect);

    NSString *drawType;
    const char *cString;

    if(sharedPrintInfo.orientation == NSPortraitOrientation){
        drawType = @"Portrait";
    }else{
        drawType = @"Landscape";
    }

    cString = [drawType cStringUsingEncoding:NSASCIIStringEncoding];

    //Draw the print mode for reference.
    CGContextRef myContext = [[NSGraphicsContext currentContext] graphicsPort];
    CGContextSelectFont(myContext, "Helvetica-Bold", 30, kCGEncodingMacRoman);
    CGContextSetCharacterSpacing(myContext, 10);
    CGContextSetTextDrawingMode(myContext, kCGTextFillStroke);
    CGContextSetRGBFillColor(myContext, 0, 0, 0, 1);//black
    CGContextSetRGBStrokeColor (myContext, 1, 1, 1, 1);//white stroke
    CGContextShowTextAtPoint(myContext, 0, 0, cString, drawType.length);

    //Control what type of page is drawn.
    switch (_myOptions){
        case drawSquare:
            [self drawSquare];
            break;
        case drawCircle:
            [self drawCircle];
            break;
        case drawRectangle:
            [self drawRectangle];
            break;
    }

}

- (void)drawSquare{
    NSLog(@"Drawing Square");

    //Because this function can only be called from drawRect we are guaranteed with the function below to be in the correct graphics context
    CGContextRef myContext = [[NSGraphicsContext currentContext] graphicsPort];

    NSRect redSquare = CGRectMake (0, 0, 200, 200 );
    redSquare.origin.y = self.bounds.size.height-redSquare.size.height;//move it to the top of the page.

    CGContextSetRGBFillColor (myContext, 1, 0, 0, 1);//set to red color
    CGContextFillRect (myContext,redSquare);//Y coordinate set to height to put it in upper left, 200 is total height of the view.

}

-(void)drawCircle{
    NSLog(@"Drawing Circle");

    //Because this function can only be called from drawRect we are guaranteed with the function below to be in the correct graphics context
    CGContextRef myContext = [[NSGraphicsContext currentContext] graphicsPort];

    CGContextSetRGBFillColor (myContext, 1, 0, 1, 1);//set to red color
    NSRect ovalFrame = CGRectMake (0, 0, 200, 200 );

    ovalFrame.origin.x=0;//from within the view it's self.
    ovalFrame.origin.y=0;//at the top of the page.

    CGContextFillEllipseInRect(myContext,ovalFrame);
}

-(void)drawRectangle{
    NSLog(@"Drawing Rectangle");

    //Because this function can only be called from drawRect we are guaranteed with the function below to be in the correct graphics context
    CGContextRef myContext = [[NSGraphicsContext currentContext] graphicsPort];

    NSRect redRectangle = CGRectMake (0, 0, 300, 100 );
    redRectangle.origin.y = self.bounds.size.height-redRectangle.size.height-(self.bounds.size.height/2);//move it to the top of the page.

    CGContextSetRGBFillColor (myContext, 1, 1, 0, 1);//set to red color
    CGContextFillRect (myContext,redRectangle);//Y coordinate set to height to put it in upper left, 200 is total height of the view.
}

@end

下面是我的 AppController 中使用这些类的示例。我简单地创建了一个按钮，并在屏幕上显示了 3 个矩形、圆形和正方形的复选框。

这里是appController.h和appController.m

#import <Foundation/Foundation.h>
#import "PSPrint.h"
#import "PSPrintView.h"

@interface AppController : NSObject
- (IBAction)printResultsButton:(id)sender;
@property (weak) IBOutlet NSButton *squareCheckBox;
@property (weak) IBOutlet NSButton *circleCheckBox;
@property (weak) IBOutlet NSButton *rectangleCheckBox;
@property (strong) PSPrint *PSPrintObject;
- (IBAction)pageSetup:(id)sender;
@end

#import "AppController.h"
#import "PSPrint.h"
#import "PSPrintView.h"

@implementation AppController

- (IBAction)printResultsButton:(id)sender {
    NSLog(@"Print Button Pressed");

    //First get the shared print info object so we know page sizes.  The shared print info object acts like a global variable.
    NSPrintInfo *sharedPrintInfo = [NSPrintInfo sharedPrintInfo];

    //initialize it's base values.
    sharedPrintInfo.leftMargin = 0;
    sharedPrintInfo.rightMargin = 0;
    sharedPrintInfo.topMargin = 0;
    sharedPrintInfo.bottomMargin = 0;

    PSPrintView *printPageView;
    NSRect frame;
    frame.size.height = sharedPrintInfo.paperSize.height-sharedPrintInfo.topMargin-sharedPrintInfo.bottomMargin;
    frame.size.width = sharedPrintInfo.paperSize.width-sharedPrintInfo.leftMargin-sharedPrintInfo.rightMargin;

    //Initiate the printObject without a frame, it's frame will be decided later.
    _PSPrintObject = [[PSPrint alloc]init];

    //[_PSPrintObject.printViews initWithCapacity:1];//start it off with a capacity of '1'
    if(_squareCheckBox.state == NSOnState){

        //Allocate a new instance of NSView into the variable printPageView
        printPageView =[[PSPrintView alloc] initWithFrame:frame];

        //Set the option for the printView for what it should draw.
        printPageView.myOptions=drawSquare;

        //Finally append the view to the PSPrint Object.
        [_PSPrintObject.printViews addObject:printPageView];

        NSLog(@"Added Square Print View To Mutable Array");
    }

    if(_circleCheckBox.state == NSOnState){
        //Allocate a new instance of NSView into the variable printPageView
        printPageView =[[PSPrintView alloc] initWithFrame:frame];

        //Set the option for the printView for what it should draw.
        printPageView.myOptions=drawCircle;

        //Finally append the view to the PSPrint Object.
        [_PSPrintObject.printViews addObject:printPageView];

        NSLog(@"Added Circle Print View To Mutable Array");
    }

    if(_rectangleCheckBox.state == NSOnState){
        //Allocate a new instance of NSView into the variable printPageView
        printPageView =[[PSPrintView alloc] initWithFrame:frame];

        //Set the option for the printView for what it should draw.
        printPageView.myOptions=drawRectangle;

        //Finally append the view to the PSPrint Object.
        [_PSPrintObject.printViews addObject:printPageView];

        NSLog(@"Added Rectangle Print View To Mutable Array");
    }

    NSLog(@"Attempting to print all views...");
    [_PSPrintObject printTheViews];//print all the views, each view being a 'page'.

}

- (IBAction)pageSetup:(id)sender {
    NSPageLayout *pageLayout = [NSPageLayout pageLayout];

    [pageLayout runModal];//runs the model for the page layout UI.  It saves the global copy of printInfo in printOperation, which can be used to make decisions

}
@end

我希望这能帮助你们中的一些人在打印方面遇到困难，我花了一些时间才做到这一点，但这些类(class)使打印变得更加容易。