Question

class OriginalImage：Form { 私人图片图片; 私人PictureBox pb;

    public OriginalImage()
    {
        pb = new PictureBox {SizeMode = PictureBoxSizeMode.CenterImage};
        pb.SizeMode = PictureBoxSizeMode.StretchImage;

        Controls.Add(pb);

        image = Image.FromFile(@"Image/original.jpg");

        this.Width = image.Width;
        this.Height = image.Height;

        this.Text = "Original image";
        this.Paint += new PaintEventHandler(Drawer);
    }

    public virtual void Drawer(object source, PaintEventArgs e)
    {
        Graphics g = pb.CreateGraphics();
        g.DrawImage(image,0,0);
    }

我在按钮点击时以其他形式调用此创建对象OriginalImage，但图像不是绘制的？哪里有问题？

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        var oi = new OriginalImage();
        oi.Show();
    }
}

Answer 1

您正在创建PictureBox并将其添加到控件中，但您实际上从未使用它（您在Paint事件中手动绘制图像）。为什么？此控件可能会遮盖表单的绘图区域，因为任何控件都会覆盖您在Paint事件中绘制的任何内容。

此外，您通过调用Graphics上的CreateGraphics而不是PictureBox本身来获取Form个对象。这是错误的，因为PictureBox的Paint事件将在此代码之后触发，删除您绘制的任何内容。

我建议您将OriginalForm代码更改为以下内容：

class OriginalImage: Form { private Image image; private PictureBox pb; public OriginalImage() { pb = new PictureBox(); pb.SizeMode = PictureBoxSizeMode.StretchImage; pb.Dock = DockStyle.Fill; // this will make the PictureBox occupy the // whole form Controls.Add(pb); image = Image.FromFile(@"Image/original.jpg"); this.ClientSize = new Size(image.Width, image.Height); // this allows you to // size the form while // accounting for the // border this.Text = "Original image"; pb.Image = image; // use this instead of drawing it yourself. } }

绘制图像的C＃WinForms问题

1 个答案: