求教显示文本问题

[cjc8279]

我调用了如下方法

- (void)drawRect:(CGRect)rect {
float black[4] = { 1, 1, 1, 1 };
CGContextRef ctx = UICurrentContext( );
int i;

CGContextSetFillColor(ctx, black);
CGContextFillRect(ctx, rect);

MyDrawText(ctx,rect);
}
void MyDrawText(CGContextRef myContext ,CGRect contextRect)
{

float w, h;
w = contextRect.size.width;
h = contextRect.size.height;

CGAffineTransform myTextTransform; // 2
CGContextSelectFont (myContext, // 3
"Times-Bold",
h/10,
kCGEncodingMacRoman);
CGContextSetCharacterSpacing (myContext, 10); // 4
CGContextSetTextDrawingMode (myContext, kCGTextFillStroke); // 5

CGContextSetRGBFillColor (myContext, 0, 0, 0, .5); // 6
CGContextSetRGBStrokeColor (myContext, 0, 0, 0, 1); // 7
myTextTransform = CGAffineTransformMakeRotation (45); // 8

CGContextSetTextMatrix (myContext, myTextTransform); // 9
CGContextShowTextAtPoint (myContext, 40, 50, "Quartz 2D", 9); // 10

}

界面上显示不出文本来，请问是啥原因呢？
谢谢~

[cjc8279]

补充：我是参考了以下的说明，但不知道为何不行。http://developer.apple.com/documentation/GraphicsImaging/Conceptual/drawingwithquartz2d/dq_text/chapter_18_section_4.html

[ruiteascjc]

可能找不到字体"Times-Bold"