iPhone图形开发绘图总结

2012-07-26

iPhone图形开发绘图小结1、绘图总结:绘图前设置:CGContextSetRGBFillColor/CGContextSetFillColorWithColor

iPhone图形开发绘图小结

1、绘图总结:

绘图前设置:

CGContextSetRGBFillColor/CGContextSetFillColorWithColor??//填充色? ? 
CGContextSetRGBStrokeColor/CGContextSetStrokeColorWithColor?//笔颜色? ? 
CGContextSetLineWidth???//线宽度??

绘图后设置:

注:? 画完图后,必须先用CGContextStrokePath来描线,即形状，后用CGContextFillPath来填充形状内的颜色.

2.常见图形绘制:

CGContextFillRect/CGContextFillRects? ? 
CGContextFillEllipseInRect? ? 
CGContextAddRect/CGContextAddRects? ? 
CGContextAddEllipseInRect? ? 
CGContextAddLines? ? 
CGContextMoveToPoint? ? 
CGContextAddLineToPoint??

3.常见控制方法:

CGContextSaveGState? ? 
CGContextRestoreGState??

4.创建内存图像context:

CGBitmapContextCreate???????<CGColorSpaceRlease? ? 
CGBitmapContextCreateImage()???<eg:? ? 
CGContextRefMyCreateBitmapContext(intpixelsWide,intpixelsHigh)? ? 
{? ? 
CGContextRef????CGColorSpaceRefcolorSpace;? ? 
void*??????????bitmapData;? ? 
int?????????????bitmapByteCount;? ? 
int?????????????bitmapBytesPerRow;? ? 
if(fprintf(stderr,"Memorynotallocated!");? ? 
returnNULL;? ? 
}? ? 
if(free(bitmapData);? ? 
fprintf(stderr,"Contextnotcreated!");? ? 
returnNULL;? ? 
}? ? 
CGColorSpaceRelease(colorSpace);? ? 
returncontext;? ? 
}??

5.图形的变换:

CGContextTranslateCTM? ? 
CGContextRotateCTM? ? 
CGContextScaleCTM??

6.常用函数:

??CGRectContainsPoint();? ? 
CGRectContainsRect();? ? 
CGRectIntersectsRect();? ? 
CGRectIntersection();? ? 
CGPointEqualToPoint();? ? 
CGSizeEqualToSize();??

7.从原图片中取小图.

CGImageCreateWithImageInRect??

8.屏幕快照:

#import?"QuartzCore/QuartzCore.h"? ? 
? 
UIGraphicsBeginImageContext(yourView.frame.size);? ? 
[[yourView?layer]?renderInContext:UIGraphicsGetCurrentContext()];? ? 
UIImage*from:http://www.cppblog.com/zhangyuntaoshe/articles/123066.html??

合并两张bit图到一张image的方法

To?graphically?merge?two?images?into?a?new?image,?you?do?something?like?this:? ? 
UIImage?*unsignedchar?*//?kCGImageAlphaPremultipliedLast?为预记录的#define?value? ? 
//?设置context上下文? ? 
CGContextRef?CGColorSpaceCreateDeviceRGB(),?kCGImageAlphaPremultipliedLast);? ? 
if?(context?!=?NULL)?{? ? 
UIGraphicsPushContext(context);? ? 
//??Image?为下载的背景图片,用于比较context? ? 
CGContextTranslateCTM(context,?0,?size.height);? ? 
CGContextScaleCTM(context,?1,?-1);? ? 
[image?drawInRect:imageRect];? ? 
[image2?drawInRect:image2Rect];? ? 
UIGraphicsPopContext();? ? 
CGImageRef?if?(imageRef?!=?NULL)?{? ? 
CGImageRelease(imageRef);? ? 
}? ? 
CGContextRelease(context);? ? 
}? ? 
free(data);? ? 
}? ? 
return?result;??

关键方法：?

CGContextRef?CGContextScaleCTM();? ? 
CGImageRef?CGImageRelease(imageRef);?

小结：iPhone图形开发绘图教程的内容介绍完了，希望本文对你有所帮助！

热点排行

图形图像

iPhone图形开发绘图总结