影响所有者窗口的元素

Question

此应用程序包含2个窗口;所有者窗口中有标签，分配了indicator1名称。方法IndicatorOn()必须更改标签的外观，但只有在从同一窗口（IndicatorOn()）调用Main Window时才会发生，如果从其他窗口调用它，则会发生零效果我的应用。我试图调试 - 一切似乎都没问题：程序成功进入case 1阻止并退出，只是与indicator1相关的命令被忽略了......

public partial class MainWindow : Form {

    public MainWindow() {
        InitializeComponent();
    }

    private void MainWindow_Load(object sender, EventArgs e) {
        ChildWindow childWindow = new ChildWindow();
        childWindow.Owner = this;
        childWindow.Show();
    }

    public void IndicatorOn (byte indicatorNumber) { // assume that it cout is small
        switch (boothNumber) {
            case 1:
                indicator1.ForeColor = System.Drawing.Color.Black;
                indicator1.BackgroundImage = ExamopleProject.Properties.Resources.IndicatorActive;
                indicator1.BackgroundImageLayout = System.Windows.Forms.ImageLayout.Stretch;
                break;
            }
            // ....
    }
}

public partial class ChildWindow : Form {

    MainWindow mainWindow;

    public ChildWindow() {
        InitializeComponent();
        mainWindow = new MainWindow();
    }

    private void Button1_Click(object sender, EventArgs e) {
    }
}