一种形式的Winform Trackbar值没有传递到另一种形式

你可以像绑定Close事件一样绑定Trackbar Scroll事件。你只需要在Form1和Form2之间建立一个"连接"。

1. 在Form2中创建一个公共属性(例如int TrackBarValue)，它返回TrackBar的实际值

2. 在Form2中创建一个公共自定义事件(例如EventHandler TrackBarValueChanged)，当TrackBar的值发生变化时将被触发

3. 从Form1绑定TrackBarValueChanged事件

如果仍然不清楚，请在评论中告诉我。

Form1.h

public Fullscreenpreview(string filename)
{
    InitializeComponent();
    this.pictureBox1.MouseMove += this.pictureBox_MouseMove;
    pictureBox1.Image = new Bitmap(filename);
    pictureBox1.Refresh();
    //to show exit button which is a seperate form
    frm3 = new Exitform();
    frm3.FormClosed += (o, e) => this.Close();
    frm3.OnTrackBarValueChanged += new EventHandler(TrackBarValueChanged_Event);
    frm3.Show();
    frm3.TopMost = true;
    //to show exit button which is a seperate form
}

private void TrackBarValueChanged_Event(Object sender, EventArgs e)
{
     ExitForm exit = (ExitForm)sender;
     MessageBox.Show("zoinks the value is = " + exit.TrackBarValue.ToString()); 
}

Form2.h

public partial class Exitform : Form
{
    private const int CpNocloseButton = 0x200;
    private bool mouseIsDown = false;
    private Point firstPoint;
    public event EventHandler OnTrackBarValueChanged;
    public Exitform()
    {
        InitializeComponent();
        this.TopMost = false;
    }
    public int TrackBarValue
    {
        get
        {
            return contrast_trackbar.Value;
        }
    }
    protected override CreateParams CreateParams
    {
        get
        {
            CreateParams myCp = base.CreateParams;
            myCp.ClassStyle = myCp.ClassStyle | CpNocloseButton;
            return myCp;
        }
    }
    private void button1_Click(object sender, EventArgs e)
    {
        this.Close();
    }
    private void label1_MouseDown(object sender, MouseEventArgs e)
    {
        firstPoint = e.Location;
        mouseIsDown = true;
        //http://stackoverflow.com/questions/3441762/how-can-i-move-windows-when-mouse-down
    }
    private void label1_MouseUp(object sender, MouseEventArgs e)
    {
        mouseIsDown = false;
    }
    private void label1_MouseMove(object sender, MouseEventArgs e)
    {
        if (mouseIsDown)
        {
            // Get the difference between the two points
            int xDiff = firstPoint.X - e.Location.X;
            int yDiff = firstPoint.Y - e.Location.Y;
            // Set the new point
            int x = this.Location.X - xDiff;
            int y = this.Location.Y - yDiff;
            this.Location = new Point(x, y);
        }
    }
    private void contrast_trackbar_Scroll(object sender, EventArgs e)
    {
        OnTrackBarValueChanged(this, EventArgs.Empty);
    }
}

Zoltan提供的答案和stackoverflow提供的答案缩放使用两种形式。给了我一直在寻找的答案。Zoom使用了两种形式，我没有立即从标题中找到。

我将此作为答案发布的唯一原因是将新代码作为单独的条目显示在Zoltan答案下方，而不是在我的代码下方向下滚动以查看他的回复。

变量名已经从第一个帖子改变了，因为我只是在试验。

形式1

public sbyte contrast
{
    get { return Exitform.contrastvalue; }
}
public Fullscreenpreview(string filename)
{
    InitializeComponent();
    this.pictureBox1.MouseMove += this.pictureBox_MouseMove;
    pictureBox1.Image = new Bitmap(filename);
    pictureBox1.Refresh();
    //to show exit button which is a separate form
    var frm3 = new Exitform();
    frm3.FormClosed += (o, e) => this.Close();
    frm3.TrackBarMoved += new Action<int>(ChangeContrast);//<< Added
    frm3.Show();
    frm3.TopMost = true;
    //to show exit button which is a separate form
    frm3.FormClosed -= (o, e) => this.Close();//<< for memory leaks
    frm3.TrackBarMoved -= new Action<int>(ChangeContrast);//<< for memory leaks
}
private void ChangeContrast(int contrastVal)
{
    MessageBox.Show("zoinks the value is = " + contrastVal);
}

形式2

public partial class Exitform : Form
{
    private const int CpNocloseButton = 0x200;
    private bool mouseIsDown = false;
    private Point firstPoint;
    public static sbyte contrastvalue = 0;
    public Exitform()
    {
        InitializeComponent();
        this.TopMost = false;
    }
    protected override CreateParams CreateParams
    {
        get
        {
            CreateParams myCp = base.CreateParams;
            myCp.ClassStyle = myCp.ClassStyle | CpNocloseButton;
            return myCp;
        }
    }
    private void button1_Click(object sender, EventArgs e)
    {
        this.Close();
    }
    private void label1_MouseDown(object sender, MouseEventArgs e)
    {
        firstPoint = e.Location;
        mouseIsDown = true;
        //https://stackoverflow.com/questions/3441762/how-can-i-move-windows-when-mouse-down
    }
    private void label1_MouseUp(object sender, MouseEventArgs e)
    {
        mouseIsDown = false;
    }
    private void label1_MouseMove(object sender, MouseEventArgs e)
    {
        if (mouseIsDown)
        {
            // Get the difference between the two points
            int xDiff = firstPoint.X - e.Location.X;
            int yDiff = firstPoint.Y - e.Location.Y;
            // Set the new point
            int x = this.Location.X - xDiff;
            int y = this.Location.Y - yDiff;
            this.Location = new Point(x, y);
        }
    }
    public event Action<int> TrackBarMoved;// << public event to sense if the trackbar is moved
    private void contrast_trackbar_Scroll(object sender, EventArgs e)
    {
        sbyte contrastVal = (sbyte)(this.contrast_trackbar.Value);//local variable just for use in trackbar
        TrackBarMoved(contrast_trackbar.Value);//pull value is trackbar moved
        string trackerbarvalue = Convert.ToString(contrastVal, CultureInfo.CurrentCulture);// convert to string to push to label
        contrastlabel.Text = trackerbarvalue;//actual push to label
        contrastvalue = (sbyte)contrast_trackbar.Value;
    }
}

除了一些变量的重命名、内部清理和向标签报告trackbar的值之外，代码只有一些小的变化。正如Zoltan正确指出的那样，我需要像绑定close事件那样绑定trackbar滚动事件。这是通过。

frm3.TrackBarMoved += new Action<int>(ChangeContrast);//<< Added

我还添加了一个退订以帮助防止资源泄漏

frm3.FormClosed -= (o, e) => this.Close();//<< for memory leaks
frm3.TrackBarMoved -= new Action<int>(ChangeContrast);//<< for memory leaks

另一种形式

public event Action<int> TrackBarMoved;// << public event to sense if the trackbar is moved

用于广播事件

谢谢安迪