在iOS 7中不推荐使用CGContextSelectFont和CGContextShowTextAtPoint.C中的等价物是什么？
解决方法
这是解决方案.这些函数已被弃用,以支持Core Text.它更先进,但需要一段时间来弄明白.这个样本绘制了“Hello World！”使用Courier字体.
- (void)drawRect:(CGRect)rect
{
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSaveGState(context);
CFStringRef font_name = CFStringCreateWithCString(NULL,"Courier",kcfStringEncodingMacRoman);
CTFontRef font = CTFontCreateWithName(font_name,36.0,NULL);
CFStringRef keys[] = { kCTFontAttributeName };
CFTypeRef values[] = { font };
CFDictionaryRef font_attributes = CFDictionaryCreate(kcfAllocatorDefault,(const void **)&keys,(const void **)&values,sizeof(keys) / sizeof(keys[0]),&kcfTypeDictionaryKeyCallBacks,&kcfTypeDictionaryValueCallBacks);
CFRelease(font_name);
CFRelease(font);
int x = 10;
int y = 10;
const char *text = "Hello World!";
CFStringRef string = CFStringCreateWithCString(NULL,text,kcfStringEncodingMacRoman);
CFAttributedStringRef attr_string = CFAttributedStringCreate(NULL,string,font_attributes);
CTLineRef line = CTLineCreateWithAttributedString(attr_string);
CGContextSetTextPosition(context,x,y);
// Core Text uses a reference coordinate system with the origin on the bottom-left
// flip the coordinate system before drawing or the text will appear upside down
CGContextTranslateCTM(context,self.bounds.size.height);
CGContextScaleCTM(context,1.0,-1.0);
CTLineDraw(line,context);
CFRelease(line);
CFRelease(string);
CFRelease(attr_string);
CGContextRestoreGState(context);
}
