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摘要

在計算機(jī)圖形學(xué)中，使用 GDI（圖形設(shè)備接口）是一種繪制圖形的方法。它是一種基于設(shè)備的方法，可以通過控制設(shè)備的像素來創(chuàng)建圖像。使用 GDI 繪制圖形是許多應(yīng)用程序中必不可少的一部分。

在 C# 中，使用 GDI 可以輕松地繪制圖形。要繪制一條線條，可以使用 Line 類。Line 類定義了一個由兩個點組成的直線。在創(chuàng)建 Line 對象時，需要指定兩個坐標(biāo)點，這兩個點將決定直線的位置和方向。

繪制完成后，我們需要釋放資源。Graphics 對象和 Pen 對象都是在創(chuàng)建時分配內(nèi)存的，因此在不需要它們時應(yīng)該及時釋放，以避免內(nèi)存泄漏。

正文

重載

一個例子

protected override void OnPaint(PaintEventArgs e)
{
    base.OnPaint(e);

    //抗鋸齒
    e.Graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;

    Pen pen =new Pen(Color.Red, 2);

    e.Graphics.DrawLine(pen, 30, 20, 200, 200);
}

image.png

使用Point

protected override void OnPaint(PaintEventArgs e)
{
    base.OnPaint(e);

    //抗鋸齒
    e.Graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;

    Pen pen = new Pen(Color.Red, 2);

    Point p1 = new Point(30, 30);

    Point p2 = new Point(200, 300);

    e.Graphics.DrawLine(pen, p1, p2);
}

使用刷子

protected override void OnPaint(PaintEventArgs e)
{
    base.OnPaint(e);

    //抗鋸齒
    e.Graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;

    Brush brush = new HatchBrush(HatchStyle.DottedGrid, Color.DarkRed);

    Pen pen = new Pen(brush, 20);

    Point p1 = new Point(30, 30);

    Point p2 = new Point(200, 300);

    e.Graphics.DrawLine(pen, p1, p2);
}

image.png

動畫樣式

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
        this.SetStyle(ControlStyles.OptimizedDoubleBuffer, true);
        this.SetStyle(ControlStyles.AllPaintingInWmPaint, true);
        this.SetStyle(ControlStyles.UserPaint, true);
        timer.Interval = 100;
        timer.Elapsed += Timer_Elapsed;
        brush = new LinearGradientBrush(new Point(0, 0), new Point(10, 10), Color.Red, Color.RoyalBlue);
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        timer.Enabled = true;

    }
    private void Timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
    {
        if (isRun)
        {
            brush = new LinearGradientBrush(new Point(0, 0), new Point(10, 10), Color.Red, Color.RoyalBlue);
            isRun = false;
        }
        else
        {
            brush = new LinearGradientBrush(new Point(0, 0), new Point(10, 10), Color.RoyalBlue, Color.Red);
            isRun = true;
        }
        this.Invoke(new Action(this.Refresh));
    }

    LinearGradientBrush brush;
    System.Timers.Timer timer = new System.Timers.Timer();
    bool isRun = false;

    protected override void OnPaint(PaintEventArgs e)
    {
        base.OnPaint(e);

        //抗鋸齒
        e.Graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
        Pen pen = new Pen(brush, 20);
        e.Graphics.DrawLine(pen, new Point(0, 0), new Point(this.Width, 0));
        e.Graphics.DrawLine(pen, new Point(0, 0), new Point(0, this.Height));
        e.Graphics.DrawLine(pen, new Point(0, this.Height-40), new Point(this.Width, this.Height- 40));
        e.Graphics.DrawLine(pen, new Point(this.Width-20,0), new Point(this.Width-20, this.Height));
        this.Update();
    }

    private void Form1_MouseMove(object sender, MouseEventArgs e)
    {
        this.Text = e.Location.X + ":" + e.Location.Y;
    }
}

image.png