用Swift在Cocoa上绘图会产生一个错误-DrawingatCocoawithSwiftCreatesanerror

When trying to draw just like in an iOS application we faced a problem. After hours of search with no luck, we decided to ask here.

当我们试图像在iOS应用程序中那样绘制时，我们遇到了一个问题。经过几个小时的搜寻，运气不好，我们决定在这里问一下。

To make a drawing we created a class as

为了绘制一个图，我们创建了一个类。

import Cocoa

class DrawImageHolder: NSView {
  override func drawRect(dirtyRect: NSRect) {
        super.drawRect(dirtyRect)
       print(" drawRect is executed  ")

       // drawing code 
  }
}

then we connected the class to a NSView like this

然后我们将类连接到NSView

But we have received

但是我们已经收到

-[NSApplication runModalForWindow:] may not be invoked inside of transaction commit (usually this means it was invoked inside of a view's -drawRect: method.) The modal dialog has been suppressed to avoid deadlock.

-[NSApplication runModalForWindow:]不能在事务提交内部调用(通常这意味着它在视图的- drawrect:方法内部调用)。模态对话框已被抑制以避免死锁。

message from console instead of drawing.

来自控制台的消息，而不是绘图。

Besides the print(" drawRect is executed ") was not executed.

此外，打印(“drawRect被执行”)没有被执行。

Most probably we are forgetting something simple.

很可能我们忘记了一些简单的事情。

1 个解决方案

class DrawImageHolder: NSView

print(" drawRect is executed  ")

class DrawImageHolder: NSView {
  override func drawRect(dirtyRect: NSRect) {
       super.drawRect(dirtyRect)
       Swift.print(" drawRect is executed  ")
  }
}