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C# 使用Graphics绘制图片时发生闪烁的问题

在做某功能时,需要实现用鼠标滚轮放大缩小图片,直接在MouseWheel中绘制图片时发生闪烁

 

百度后顺利解决

 

几个步骤

1.设置Form的DoubleBuffered属性为True

2.在MouseWheel中调用 this.Invalidate()方法(会触发OnPaint事件)

3.重写OnPaint,在OnPaint中绘制需要绘制的图像

 

代码如下:

 

    public partial class Form1 : Form    {        int width, height;        string path = "C:\\Users\\Public\\Pictures\\Sample Pictures\\Penguins.jpg";        Image img = null;        public Form1()        {            InitializeComponent();            this.DoubleBuffered = true;            img = Image.FromFile(path);            width = img.Width;            height = img.Height;            this.MouseWheel += new MouseEventHandler(Form1_MouseWheel);        }        void Form1_MouseWheel(object sender, MouseEventArgs e)        {            width += (e.Delta / 5);            height += (e.Delta / 5);            this.Invalidate();        }        protected override void OnPaint(PaintEventArgs e)        {            base.OnPaint(e);            Rectangle rect = new Rectangle(0, 0, width, height);            e.Graphics.Clear(SystemColors.Control);            e.Graphics.DrawImage(img, rect);        }    }

 

C# 使用Graphics绘制图片时发生闪烁的问题