PropertyGrid - 获取所选位图的文件路径

Question

我将PropertyGrid 的SelectedObject 设置为具有Bitmap 属性的对象：

public class Obj
{   
    private Bitmap myimage;
    [Category("Main Category")]
    [Description("Your favorite image")]
    public Bitmap MyImage
    {
        get { return myimage; }
        set
        {
            myimage = value;
        }
    }
}

这会自动在PropertyGrid 中显示属性，并带有一个小按钮，用户可以单击该小按钮来选择图像。如何获取这张图片的文件路径？

（另外，有什么方法可以覆盖弹出的对话框并放入我自己的对话框？我知道这是一个单独的问题，所以我可能会单独发布。）

Answer 1

如何获取此图片的文件路径？ 另外，有什么办法可以覆盖弹出的对话框并放入我自己的对话框？

要实现这两种方法，一种方法是创建一个新的UITypeEditor：

public class BitmapLocationEditor : UITypeEditor
{

}

我重写了GetEditStyle、EditValue、GetPaintvalueSupported 和PaintValue 方法。

// Displays an ellipsis (...) button to start a modal dialog box
public override UITypeEditorEditStyle GetEditStyle(ITypeDescriptorContext context)
{
    return UITypeEditorEditStyle.Modal;
}

// Edits the value of the specified object using the editor style indicated by the GetEditStyle method.
public override object EditValue(ITypeDescriptorContext context,
                                 IServiceProvider provider,
                                 object value)
{
    // Show the dialog we use to open the file.
    // You could use a custom one at this point to provide the file path and the image.
    using (OpenFileDialog openFileDialog = new OpenFileDialog())
    {
        openFileDialog.Filter = "Image files (*.bmp | *.bmp;";

        if (openFileDialog.ShowDialog() == DialogResult.OK)
        {
            Bitmap bitmap = new Bitmap(openFileDialog.FileName);
            bitmap.SetPath(openFileDialog.FileName);

            return bitmap;
        }
    }

    return value;
}

// Indicates whether the specified context supports painting
// a representation of an object's value within the specified context.
public override bool GetPaintValueSupported(ITypeDescriptorContext context)
{
    return true;
}

// Paints a representation of the value of an object using the specified PaintValueEventArgs.
public override void PaintValue(PaintValueEventArgs e)
{
    if (e.Value != null)
    {
        // Get image
        Bitmap bmp = (Bitmap)e.Value;

        // This rectangle indicates the area of the Properties window to draw a representation of the value within.
        Rectangle destRect = e.Bounds;

        // Optional to set the default transparent color transparent for this image.
        bmp.MakeTransparent();

        // Draw image
        e.Graphics.DrawImage(bmp, destRect);
    }
}

您的Obj 类应该保持不变，除了添加一个属性以利用我们新的BitmapLocationEditor 类：

public class Obj
{
    private Bitmap myImage;

    [Category("Main Category")]
    [Description("Your favorite image")]
    [Editor(typeof(BitmapLocationEditor), typeof(UITypeEditor))]
    public Bitmap MyImage
    {
        get { return myImage; }
        set
        {
            myImage = value;
        }
    }
}

EditValue 方法中使用的SetPath 方法只是设置Bitmap.Tag 属性的扩展方法。您可以稍后使用GetPath 方法来检索图像文件的实际路径。

public static class BitmapExtension
{
    public static void SetPath(this Bitmap bitmap, string path)
    {
        bitmap.Tag = path;
    }

    public static string GetPath(this Bitmap bitmap)
    {
        return bitmap.Tag as string;
    }
}

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