Question

我想将numlock按钮用于numlock之外的其他东西。所以基本上我想在按下时关闭numlock并保持关闭状态。我可以捕捉按钮按下但仍然可以打开/关闭按钮。我总是想要它。有什么建议吗？

不确定为什么有人想知道我为什么要这样做但这就是原因：我有一个蓝牙数字键盘，我想用来控制一台机器。这证明了这个问题吗？

经过几个小时的研究后，我发现了以下代码，这些代码可以解决问题：

import UIKit

class PhotosViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource {

var collectionView: UICollectionView!

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
    layout.sectionInset = UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10)
    layout.itemSize = CGSize(width: 300, height: 490)

    collectionView = UICollectionView(frame: self.view.frame, collectionViewLayout: layout)
    collectionView.dataSource = self
    collectionView.delegate = self
    collectionView!.registerClass(FoodCell.self, forCellWithReuseIdentifier: "Cell")
    collectionView.backgroundColor = UIColor.whiteColor()
    self.view.addSubview(collectionView)
}

override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(animated)
}

func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return images.count
}

var images: [UIImage] = [

]

func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCellWithReuseIdentifier("Cell", forIndexPath: indexPath) as! FoodCell
    cell.textLabel.text = ""
    cell.imageView.image = images[indexPath.row]
    return cell
}

func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath)
{
    print("User tapped on item \(indexPath.row)")
}


override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
  }
}

Answer 1

以下是一个例子：

public static class NativeMethods
{
    public const byte VK_NUMLOCK = 0x90;
    public const uint KEYEVENTF_EXTENDEDKEY = 1;
    public const int KEYEVENTF_KEYUP = 0x2;

    [DllImport("user32.dll")]
    public static extern void keybd_event(byte bVk, byte bScan, uint dwFlags, int dwExtraInfo);

    public static void SimulateKeyPress(byte keyCode)
    {
        keybd_event(VK_NUMLOCK, 0x45, KEYEVENTF_EXTENDEDKEY, 0);
        keybd_event(VK_NUMLOCK, 0x45, KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP, 0);
    }
}

public partial class Form1 : Form
{
    private bool protectKeys; // To protect from inifite keypress chain reactions

    public Form1()
    {
        InitializeComponent();
    }

    private void Form1_KeyDown(object sender, KeyEventArgs e)
    {
        if (protectKeys)
            return;

        if (e.KeyCode == Keys.NumLock && 
            !(new Microsoft.VisualBasic.Devices.Keyboard().NumLock))
        {
            protectKeys = true;
            NativeMethods.SimulateKeyPress(NativeMethods.VK_NUMLOCK);
            protectKeys = false;
        }
    }
}

在c＃中保持numlock关闭

1 个答案: