cocoa - 鼠标拖动 : on CGRect

Question

我试图拖动CGRect，但没有任何反应。矩形保留在同一个地方。这是我的 mouseDragged: 代码:

-(void)mouseDragged:(NSEvent *)theEvent{

NSPoint eventLocation = [theEvent locationInWindow];
NSPoint location = [self convertPoint:eventLocation fromView:self];

int locationX = location.x;
int locationY = location.y;

[self setNeedsDisplay:TRUE];

if(CGRectContainsPoint(myRect, location)){

myRect.origin.x = locationX;
myRect.origin.y = locationY;
}
}

此代码位于 NSView 内部。我在 drawRect 中绘制矩形 myRect:

这是我的绘制矩形:

- (void)drawRect:(NSRect)rect
{

int width = self.bounds.size.width;
int height = self.bounds.size.height;

myRect = CGRectMake((width/2)-50, (height /2)-50, 100, 100);


CGContextRef myContext = [[NSGraphicsContext currentContext] graphicsPort];
CGContextSetRGBFillColor(myContext, 1, 0, 0, 1);
CGContextFillRect(myContext, myRect);

 NSLog(@"drawRect: called");

}

有什么想法吗？

Answer 1

您始终将 myRect 设置为 drawRect: 内的常量值。看来您想要的是在 drawRect: 中根本不设置 myRect 并用其当前值绘制它。所以像这样:

- (void)drawRect:(NSRect)rect
{
    CGContextRef myContext = [[NSGraphicsContext currentContext] graphicsPort];
    CGContextSetRGBFillColor(myContext, 1, 0, 0, 1);
    CGContextFillRect(myContext, myRect);

    NSLog(@"drawRect: called");
}