如何使用该图像上的鼠标位置进行放大 [英] How to zoom in using Mouse Position on that image

问题描述

我有一个userControl库，它由主面板和一个PictureBox组成，我想制作一个可缩放的PictureBox工具，我使用主面板的mouseWheel事件进行放大和缩小，我无法弄清楚这个问题如何通过鼠标在图像上的位置进行放大，所以每当放大时，缩放都移到面板的左上角，那么如何解决呢？

I have a userControl library, which consists of the main Panel and a PictureBox, I want to make a zoomable PictureBox tool, I zoom in and out using mouseWheel event of the main Panel, the problem that I can't figure out how do I zoom in by the mouse position on the image, so whenever I zoom in, the zoom goes the Top-Left corner of the panel, so how do I fix that?

private double ZOOMFACTOR = 1.15;   // = 15% smaller or larger
private int MINMAX = 5;
void picPanel_MouseWheel(object sender, MouseEventArgs e)
    {
        if (e.Delta > 0)
        {
            ZoomIn();
        }
        else
        {
            ZoomOut();
        }
    }

    private void ZoomIn()
    {
        if ((picBox.Width < (MINMAX * this.Width)) &&
            (picBox.Height < (MINMAX * this.Height)))
        {
            picBox.Width = Convert.ToInt32(picBox.Width * ZOOMFACTOR);
            picBox.Height = Convert.ToInt32(picBox.Height * ZOOMFACTOR);
        }
    } 
    private void picBox_MouseEnter(object sender, EventArgs e)
    {
        if (picBox.Focused) return;
        picBox.Focus();
    }

更新：

我已经尝试过了，看起来像在工作，但并不完全应该！有什么想法吗？

I have tried this, it looks like working, but not exactly as it should be!! Any ideas?

    private void ZoomIn()
    {
        if ((picBox.Width < (MINMAX * this.Width)) &&
            (picBox.Height < (MINMAX * this.Height)))
        {
            picBox.Width = Convert.ToInt32(picBox.Width * ZOOMFACTOR);
            picBox.Height = Convert.ToInt32(picBox.Height * ZOOMFACTOR);

            Point p = this.AutoScrollPosition;
            int deltaX = e.X - p.X;
            int deltaY = e.Y - p.Y;
            this.AutoScrollPosition = new Point(deltaX, deltaY);
        }
    } 

推荐答案

此是鼠标位置上缩放图像的示例。...
经过测试验证。

This is the example of Zoom image on mouse position.... tested verified.

protected override void OnMouseWheel(MouseEventArgs ea)
{
    //  flag = 1;
    // Override OnMouseWheel event, for zooming in/out with the scroll wheel
    if (picmap1.Image != null)
    {
        // If the mouse wheel is moved forward (Zoom in)
        if (ea.Delta > 0)
        {
            // Check if the pictureBox dimensions are in range (15 is the minimum and maximum zoom level)
            if ((picmap1.Width < (15 * this.Width)) && (picmap1.Height < (15 * this.Height)))
            {
                // Change the size of the picturebox, multiply it by the ZOOMFACTOR
                picmap1.Width = (int)(picmap1.Width * 1.25);
                picmap1.Height = (int)(picmap1.Height * 1.25);

                // Formula to move the picturebox, to zoom in the point selected by the mouse cursor
                picmap1.Top = (int)(ea.Y - 1.25 * (ea.Y - picmap1.Top));
                picmap1.Left = (int)(ea.X - 1.25 * (ea.X - picmap1.Left));
            }
        }
        else
        {
            // Check if the pictureBox dimensions are in range (15 is the minimum and maximum zoom level)
            if ((picmap1.Width > (imagemappan.Width)) && (picmap1.Height > (imagemappan.Height)))
            {
                // Change the size of the picturebox, divide it by the ZOOMFACTOR
                picmap1.Width = (int)(picmap1.Width / 1.25);
                picmap1.Height = (int)(picmap1.Height / 1.25);

                // Formula to move the picturebox, to zoom in the point selected by the mouse cursor
                picmap1.Top = (int)(ea.Y - 0.80 * (ea.Y - picmap1.Top));
                picmap1.Left = (int)(ea.X - 0.80 * (ea.X - picmap1.Left));
            }
        }
    }
}

这篇关于如何使用该图像上的鼠标位置进行放大的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！