Question

我正在尝试使用c＃中的switch语句在文本框中显示一些文本，并根据我从组合框中选择的选项在另一个文本框中显示数字。我创建了自己的名为“Devices”的类，并在类中创建了几个对象。我还为每个对象提供了几个属性（例如DeviceName，DeviceRating）。但是，当我启动表单并从我的组合框中选择一个选项时，第一个选项按计划工作（文本显示在相关文本框中），但所有选项都显示空白文本框。有关为什么会发生这种情况的任何想法？

以下是我的属性代码：

 private void Form1_Load(object sender, EventArgs e)
    {

        // Gives properties of each object in the 'Devices' class.

        WashingMachine.DeviceName = "Washing Machine";
        WashingMachine.DeviceRating = 1200;


        Dishwasher.DeviceName = "Dishwasher";
        Dishwasher.DeviceRating = 1;
        ;

        OvenHob.DeviceName = "Oven/Hob";
        OvenHob.DeviceRating = 1;
        ;

        TowelRail.DeviceName = "Towel Rail";
        TowelRail.DeviceRating = 1;


        Hairdryer.DeviceName = "Hairdryer";
        Hairdryer.DeviceRating = 1;


        Shower.DeviceName = "Shower";
        Shower.DeviceRating = 1;

    }

以下是我创建的类的代码：

class Devices
    {
        public string DeviceName;
        public int DeviceRating;
        public int UsedMins;
    }

以下是我在类中创建新对象的代码：

// Creating new objects under the 'Devices' class.

    Devices WashingMachine = new Devices();
    Devices Dishwasher = new Devices();
    Devices OvenHob = new Devices();
    Devices TowelRail = new Devices();
    Devices Hairdryer = new Devices();
    Devices Shower = new Devices();
    Devices PhoneCharger = new Devices();
    Devices TabletCharger = new Devices();
    Devices ElectricBlanket = new Devices();

这里是switch语句控制组合框中每个案例的情况（注意组合框列表与列出的对象的顺序相同）：

 // Puts a Name and Power Rating into the textboxes based on the chosen device
    private void comboBox3_SelectedIndexChanged(object sender, EventArgs e)
    {
        switch (comboBox1.SelectedIndex)
        {
            case 0:
                DeviceName.Text = WashingMachine.DeviceName;
                PowerRating.Text = WashingMachine.DeviceRating.ToString();
                break;
            case 1:
                DeviceName.Text = Dishwasher.DeviceName;
                PowerRating.Text = Dishwasher.DeviceName.ToString();
                break;
            case 2:
                DeviceName.Text = OvenHob.DeviceName;
                PowerRating.Text = OvenHob.DeviceRating.ToString();
                break;
            case 3:
                DeviceName.Text = TowelRail.DeviceName;
                PowerRating.Text = TowelRail.DeviceRating.ToString();
                break;
            case 4:
                DeviceName.Text = Hairdryer.DeviceName;
                PowerRating.Text = Hairdryer.DeviceRating.ToString();
                break;
            case 5:
                DeviceName.Text = Shower.DeviceName;
                PowerRating.Text = Shower.DeviceRating.ToString();
                break;
        }


    }

Answer 1

这有点不匹配。您是否为ComboBox命名为comboBox1并使用名为comboBox3_SelectedIndexChanged()的事件？

private void comboBox3_SelectedIndexChanged(object sender, EventArgs e)
{
    switch (comboBox1.SelectedIndex)
    {

不应该是

private void comboBox3_SelectedIndexChanged(object sender, EventArgs e)
{
    switch (comboBox3.SelectedIndex)
    {

请原谅，如果偶然保留了偶数名称。另外，你的代码中是否真的有这些额外的分号？

Dishwasher.DeviceRating = 1;
        ;

和

OvenHob.DeviceRating = 1;
        ;

使用带有switch语句的组合框c＃

1 个答案: