我有一个带有动态生成的图形上下文的 UIView。它的正常大小是 100x100，但它可以放大到 200x200，所以我希望它的大小实际上是 200x200，以便看起来很好并且不会模糊，但是它显示出来。
如何始终在 drawRect 中将其绘制为 200x200，以 100 的大小或 200 的大小显示？如果我以 100x100 显示它，则传递给 drawRect 的矩形小于我需要绘制的区域。
我的代码：
- (void) drawRect:(CGRect)rect
{
CGContextRef ctx = UIGraphicsGetCurrentContext();
// prevent the drawings to be flipped
CGContextTranslateCTM(ctx, 0, rect.size.height);
CGContextScaleCTM(ctx, 1.0, -1.0);
CGContextDrawImage(ctx, CGRectMake(0, 0, rect.size.width, rect.size.height), [UIImage imageNamed:@"actionBg.png"].CGImage);
// generate the overlay
if ([self isActive] == NO && self.fullDelay != 0) { // TODO: remove fullDelay check!
UIGraphicsBeginImageContextWithOptions(rect.size, NO, 0.0);
CGContextRef overlayCtx = UIGraphicsGetCurrentContext();
int segmentSize = (rect.size.height / [self fullDelay]);
for (int i=0; i<[self fullDelay]; i++) {
float alpha = 0.9 - (([self fullDelay] * 0.1) - (i * 0.1));
[[UIColor colorWithRed:120.0/255.0 green:14.0/255.0 blue:14.0/255.0 alpha:alpha] setFill];
if (currentDelay > i) {
CGRect r = CGRectMake(0, i * segmentSize, rect.size.width, segmentSize);
CGContextFillRect(overlayCtx, r);
}
[[UIColor colorWithRed:1 green:1 blue:1 alpha:0.3] setFill];
CGRect line = CGRectMake(0, (i * segmentSize) + segmentSize - 1 , rect.size.width, 1);
CGContextFillRect(overlayCtx, line);
}
UIImage *overlay = UIGraphicsGetImageFromCurrentImageContext();
UIImage *overlayMasked = [TDUtilities maskImage:overlay withMask:[UIImage imageNamed:@"actionMask.png"]];
// prevent the drawings to be flipped
CGContextTranslateCTM(ctx, 0, rect.size.height);
CGContextScaleCTM(ctx, 1.0, -1.0);
// put the overlay
CGContextSetBlendMode(ctx, kCGBlendModeMultiply);
CGContextDrawImage(ctx, rect, overlayMasked.CGImage);
CGContextSetBlendMode(ctx, kCGBlendModeNormal);
UIGraphicsEndImageContext();
}
// prevent the drawings to be flipped
CGContextTranslateCTM(ctx, 0, rect.size.height);
CGContextScaleCTM(ctx, 1.0, -1.0);
// draw the delay symbol
CGContextDrawImage(ctx, rect, [UIImage imageNamed:@"delaySymbol.png"].CGImage);
CGContextSetAlpha(ctx, 0.8);
// draw the symbol
NSString *imgName = [K_ACTION_IMAGES objectAtIndex:[self actionType]];
CGContextDrawImage(ctx, rect, [UIImage imageNamed:imgName].CGImage);
CGContextSetAlpha(ctx, 1);
// draw the delay number
imgName = [NSString stringWithFormat:@"%d.png", [self fullDelay]];
CGContextDrawImage(ctx, rect, [UIImage imageNamed:imgName].CGImage);
// draw the priority number
imgName = [NSString stringWithFormat:@"%d.png", [self actionType]];
CGContextDrawImage(ctx, CGRectMake(32, 0, rect.size.width, rect.size.height), [UIImage imageNamed:imgName].CGImage);
}