winform中 private void comboBox1_SelectedIndexChanged(object sender, EventArgs e) { } private void button1_Click(object sender, EventArgs e) { comboBox1.Items.Clear(); videoDevices = new FilterInfoCollection(FilterCategory.VideoInputDevice); for (int i = 0; i < videoDevices.Count; i++) comboBox1.Items.Add(videoDevices[i].Name); comboBox1.Text = comboBox1.Items[0].ToString(); } 取消按钮，让combobox实现功能

如果你想要在取消按钮上实现comboBox更新的功能，你可以在取消按钮的Click事件处理程序中调用UpdateComboBox函数，UpdateComboBox函数中的代码会更新comboBox的下拉列表数据。

下面是一个简单的实现：

private void UpdateComboBox()
{
    comboBox1.Items.Clear();
    videoDevices = new FilterInfoCollection(FilterCategory.VideoInputDevice);
    for (int i = 0; i < videoDevices.Count; i++)
        comboBox1.Items.Add(videoDevices[i].Name);
    comboBox1.Text = comboBox1.Items[0].ToString();  
}

private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
    // Do something when the selected index of comboBox1 changes
}

private void button1_Click(object sender, EventArgs e)
{
    // Do something when the button1 is clicked
}

private void button2_Click(object sender, EventArgs e)
{
    UpdateComboBox();
}

在这个示例中，我们添加了一个名为button2的按钮，并将其Click事件处理程序设置为UpdateComboBox函数。当用户点击button2时，UpdateComboBox函数会更新comboBox1的下拉列表数据。