使用打开文件对话框将位图图像加载到 Windows 窗体中

问题描述

我需要使用打开文件对话框以窗口形式打开位图图像(我将从驱动器加载它).图像应适合图片框.

I need to open the bitmap image in the window form using open file dialog (I will load it from drive). The image should fit in the picture box.

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();
}

推荐答案

您必须创建 Bitmap 类，使用 构造函数重载，从磁盘上的文件加载图像.在编写代码时，您正在尝试使用 PictureBox.Image 属性，就好像它是一种方法.

You have to create an instance of the Bitmap class, using the constructor overload that loads an image from a file on disk. As your code is written now, you're trying to use the PictureBox.Image property as if it were a method.

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

Change your code to look like this (also taking advantage of the using statement to ensure proper disposal, rather than manually calling the Dispose method):

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，这不会在表单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表单中.您需要将刚刚创建的新图片框控件添加到表单的 Controls 集合 使用 Add 方法.请注意在此处添加到上述代码的行:

Of course, that's not going to display the image anywhere on your form because the picture box control that you've created hasn't been added to the form. You need to add the new picture box control that you've just created to the form's Controls collection using the Add method. Note the line added to the above code here:

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);
        }
    }
}