setNeedsDisplay不工作？ [英] setNeedsDisplay not working?

问题描述

在简单的可可应用程序中重绘自定义视图时出现问题。绘图基于由简单的NSSlider改变的一个参数。但是，虽然我实现了-setParameter：和-parameter方法，并绑定滑块的值到接口构建器中的参数，我似乎不能自定义视图重绘本身。

I have a problem redrawing a custom view in simple cocoa application. Drawing is based on one parameter that is being changed by a simple NSSlider. However, although i implement -setParameter: and -parameter methods and bind slider's value to that parameter in interface builder i cannot seem to make a custom view to redraw itself.

重绘的代码如下：

- (void)setParameter:(int)newParameter {
  parameter = newParamter;
  NSLog(@"Updated parameter: %d", parameter);
  [self setNeedsDisplay:YES];
}

我获得有关设置新参数的消息，重绘本身。欢迎任何想法！

I DO get the message about setting the new parameter although the view doesn't redraw itself. Any ideas are welcome!

推荐答案

通常的语法是： [self setNeedsDisplay：YES] ，虽然我认为这意味着相同的事情。你是实现 - （void）drawRect：（NSRect）rect 方法，或使用 drawRect：超类？

The usual syntax is: [self setNeedsDisplay:YES], although I would assume that that means the same thing. Are you implementing the - (void)drawRect:(NSRect)rect method, or using the drawRect: method of your superclass?

这篇关于setNeedsDisplay不工作？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！