winfrom-容器控件对象的滚轮事件

川长思鸟来 2022-07-12 01:09 159阅读 0赞

滚轮事件发生一定要激活当前的目标控件，比如目标控件要有焦点，事件本身简单，就是**MouseWheel**

下面举例panel：

private void panelsplit_MouseEnter(object sender, EventArgs e)
            {
                this.panelsplit.MouseWheel += new MouseEventHandler(panelsplit_MouseWheel);
                this.panelsplit.Focus();
            }
            private void panelsplit_MouseLeave(object sender, EventArgs e)
            {
                this.panelsplit.MouseWheel -= new MouseEventHandler(panelsplit_MouseWheel); 
            }
    
            private int sumcount = 0;
            private int spacing = 60; //线条间距
            private void panelsplit_MouseWheel(object sender, MouseEventArgs e)
            {
                sumcount += e.Delta; //负的放大，正的缩小
    
                int newsp = sumcount / 120 + spacing;
                AddMsg(newsp);
    
                //...
    
                panelsplit.Refresh();
                panelsplit.Invalidate();
                panelsplit.Update();
            }

private void AddMsg(object msg)
            {
                bool scroll = false;
                if (this.listBox1.TopIndex == this.listBox1.Items.Count - (int)(this.listBox1.Height / this.listBox1.ItemHeight))
                    scroll = true;
    
                this.listBox1.Items.Add(msg);
    
                if (scroll)
                    this.listBox1.TopIndex = this.listBox1.Items.Count - (int)(this.listBox1.Height / this.listBox1.ItemHeight);
    
                this.listBox1.SelectedIndex = this.listBox1.Items.Count - 1;
            }

鼠标在控件上时响应滚动，移出的之后删除事件不响应，代码只是demo，具体看自己的设计了

![SouthEast][]

[SouthEast]: /images/20220711/20904478867a471fb34297e54983dff9.png