c# - 使用打开文件对话框将位图图像加载到 Windows 窗体中

Question

我需要使用打开文件对话框在窗口形式中打开位图图像(我将从驱动器加载它)。图片应适合图片框。

这是我试过的代码:

private void button1_Click(object sender, EventArgs e)
{
    var dialog = new OpenFileDialog();

    dialog.Title  = "Open Image";
    dialog.Filter = "bmp files (*.bmp)|*.bmp";

    if (dialog.ShowDialog() == DialogResult.OK)
    {                     
        var PictureBox1 = new PictureBox();                    
        PictureBox1.Image(dialog.FileName);
    }

    dialog.Dispose();
}

Answer 1

您必须创建 Bitmap class 的实例, 使用 constructor overload从磁盘上的文件加载图像。现在编写代码时，您正在尝试使用 PictureBox.Image 属性，就好像它是一个方法。

将您的代码更改为如下所示(同时利用 using statement 确保正确处理，而不是手动调用 Dispose 方法):

private void button1_Click(object sender, EventArgs e)
{
    // Wrap the creation of the OpenFileDialog instance in a using statement,
    // rather than manually calling the Dispose method to ensure proper disposal
    using (OpenFileDialog dlg = new OpenFileDialog())
    {
        dlg.Title = "Open Image";
        dlg.Filter = "bmp files (*.bmp)|*.bmp";

        if (dlg.ShowDialog() == DialogResult.OK)
        {
            PictureBox PictureBox1 = new PictureBox();

            // Create a new Bitmap object from the picture file on disk,
            // and assign that to the PictureBox.Image property
            PictureBox1.Image = new Bitmap(dlg.FileName);
        }
    }
}

当然，这不会在窗体上的任何位置显示图像，因为您创建的图片框控件尚未添加到窗体中。您需要将刚刚创建的新图片框控件添加到窗体的 Controls collection 中。使用 Add method .请注意在此处添加到上述代码的行:

private void button1_Click(object sender, EventArgs e)
{
    using (OpenFileDialog dlg = new OpenFileDialog())
    {
        dlg.Title = "Open Image";
        dlg.Filter = "bmp files (*.bmp)|*.bmp";

        if (dlg.ShowDialog() == DialogResult.OK)
        {
            PictureBox PictureBox1 = new PictureBox();
            PictureBox1.Image = new Bitmap(dlg.FileName);

            // Add the new control to its parent's controls collection
            this.Controls.Add(PictureBox1);
        }
    }
}