objective-c - 如何检查 CGWindowID 是否仍然有效

Question

如果我得到如下所示的 CGWindowID (_windowID)...

NSArray *windowList = (__bridge NSArray *)CGWindowListCopyWindowInfo(kCGWindowListOptionOnScreenOnly, kCGNullWindowID);
for (NSDictionary *info in windowList) { 
    if ([[info objectForKey:(NSString *)kCGWindowOwnerName] isEqualToString:@"window name"] && ![[info objectForKey:(NSString *)kCGWindowName] isEqualToString:@""]) {
        _windowID = [[info objectForKey:(NSString *)kCGWindowNumber] unsignedIntValue];
    }
}

如何正确测试窗口 id 是否仍然有效并且窗口尚未关闭？我是否只运行类似的代码来检查窗口 ID 是否存在？

提前致谢

Answer 1

kCGWindowListOptionOnScreenOnly 常量的文档说:

List all windows that are currently onscreen. Windows are returned in order from front to back. When retrieving a list with this option, the relativeToWindow parameter should be set to kCGNullWindowID.

因此窗口肯定会出现在屏幕上，因为在调用 CGWindowListCopyWindowInfo 和您对其执行的操作之间似乎没有发生任何事情。

也许您想进行测试以确保它们没有被隐藏或最小化？