摘要

在C#开发中，GDI+是一个强大的图形库，可以用来创建各种图形和图像。本文将介绍如何使用GDI+在C#中绘制长方形，并详细讨论常用的方法与属性。

正文

Graphics类

在GDI+中，我们使用Graphics类来进行图形绘制。以下是一些常用的Graphics类方法和属性，用于绘制长方形：

1. DrawRectangle()：这个方法用于绘制一个矩形，您可以指定矩形的位置、大小、颜色等参数。
2. FillRectangle()：与DrawRectangle()类似，但用于填充矩形内部的颜色。

示例1：绘制一个红色矩形

C#
private void DrawRedRectangle()
{
    using (Graphics g = this.CreateGraphics())
    {
        Pen pen = new Pen(Color.Red, 2);
        g.DrawRectangle(pen, 50, 50, 100, 80);
    }
}

示例2：绘制一个虚线矩形

C#
private void DrawDashedRectangle()
{
    using (Graphics g = this.CreateGraphics())
    {
        Pen pen = new Pen(Color.Green, 2);
        pen.DashStyle = DashStyle.Dash;
        g.DrawRectangle(pen, 250, 250, 80, 60);
    }
}

示例3：绘制一个库存图

C#
public partial class Form1 : Form
{
    private Rectangle[] inventoryLocations;

    public Form1()
    {
        InitializeComponent();
        this.Text = "库存库位图";
        this.Size = new Size(800, 600);
        this.inventoryLocations = new Rectangle[20]; // 假设有10个库位

        // 初始化库位位置和状态
        InitializeInventoryLocations();

        this.Paint += new PaintEventHandler(InventoryLocationMap_Paint);
    }
    private void InitializeInventoryLocations()
    {
        // 假设库位状态为：0表示空闲、1表示已使用、2表示损坏
        int[] locationStatus = { 0, 1, 0, 1, 2, 0, 0, 1, 0, 1,0, 1, 0, 1, 2, 0, 0, 1, 0, 1 };
        int locationWidth = 50;
        int locationHeight = 50;
        int startX = 50;
        int startY = 50;

        for (int i = 0; i < this.inventoryLocations.Length; i++)
        {
            int x = startX + (i % 5) * (locationWidth + 10);
            int y = startY + (i / 5) * (locationHeight + 10);

            this.inventoryLocations[i] = new Rectangle(x, y, locationWidth, locationHeight);
        }
    }

    private void InventoryLocationMap_Paint(object sender, PaintEventArgs e)
    {
        Graphics g = e.Graphics;

        for (int i = 0; i < this.inventoryLocations.Length; i++)
        {
            Rectangle location = this.inventoryLocations[i];

            // 根据库位状态绘制不同颜色的矩形
            if (i % 3 == 0)
            {
                g.FillRectangle(Brushes.Green, location);
            }
            else if (i % 3 == 1)
            {
                g.FillRectangle(Brushes.Blue, location);
            }
            else
            {
                g.FillRectangle(Brushes.Red, location);
            }

            g.DrawRectangle(Pens.Black, location);
        }
    }


}