我有一个VB.NET WinForms应用程序。 我用GDI +以编程方式在面板上绘制了一堆形状。 现在我想以某种方式高亮显示该面板的一个小矩形部分。突出显示的区域将移动很多。我不想重绘整个面板,因为涉及的处理太多而且会导致闪烁。 这是最好的方法吗?
感谢。
答案 0 :(得分:1)
您可以将透明面板添加为现有面板的子面(并将其停靠),然后在透明面板上进行高光显示吗?
这是一个非常基本的例子:
public partial class Form1 : Form
{
private Panel pan = new Panel();
private Panel trans = new Panel();
private bool clicked { get; set; }
private Point mouse { get; set; }
public Form1()
{
InitializeComponent();
this.Load += new EventHandler(Form1_Load);
}
public void Form1_Load(object sender, EventArgs e)
{
pan.Dock = DockStyle.Fill;
pan.BackColor = Color.White;
trans.Dock = DockStyle.Fill;
trans.BackColor = Color.FromArgb(0, 0, 0, 0);
pan.Paint += new PaintEventHandler(DrawSomeShapes);
trans.MouseClick += new MouseEventHandler(trans_MouseClick);
trans.Paint += new PaintEventHandler(DrawHighlight);
pan.Controls.Add(trans);
this.Controls.Add(pan);
trans.BringToFront();
}
public void DrawSomeShapes(object sender, PaintEventArgs e)
{
var g = e.Graphics;
var p = new Pen(Color.Black, 1F);
g.DrawRectangle(p, new Rectangle(0, 0, 100, 100));
g.DrawRectangle(p, new Rectangle(20, 20, 50, 50));
g.DrawRectangle(p, new Rectangle(10, 50, 100, 25));
g.DrawRectangle(new Pen(Color.Red, 1F), new Rectangle(new Point(50, 50), new Size(50, 50)));
}
public void DrawHighlight(object sender, PaintEventArgs e)
{
if (clicked)
{
var g = e.Graphics;
var b = new SolidBrush(Color.FromArgb(50, 50, 50, 50));
g.FillRectangle(b, mouse.X, mouse.Y, 50, 50);
clicked = false;
}
}
public void trans_MouseClick(object sender, MouseEventArgs e)
{
mouse = e.Location;
trans.Invalidate();
clicked = true;
}
}