这没有任何作用:
NSImage* testImage = [[NSImage alloc] initWithSize:NSMakeSize(2.0,2.0)];
[testImage lockFocus];
[[NSImage imageNamed:@"testImage"] drawAtPoint:NSMakePoint(1.0,1.0) fromRect:NSZeroRect operation:NSCompositeCopy fraction:1.0];
[testImage unlockFocus];
[levelView setImage:testImage];
...但这确实:
[levelView setImage:[NSImage imageNamed:@"testImage"]];
在我看来,如果后者产生可见的结果,那么前者也应该如此。我想我在某个地方犯了一个愚蠢的错误?