c# - 如何将图像右对齐，底部在图片框中

Question

我的 picturebox1 比我要加载的图像大得多。我想要做的是将此图像对齐到右侧，并将图片框的底部对齐，如屏幕截图所示:

编辑:工作

 private void FromCameraPictureBox_Paint(object sender, PaintEventArgs e)
    {

        if (loadimage == true)
        {
            var image = new Bitmap(@"image.jpg");
            if (image != null)
            {
                var g = e.Graphics;
                // -- Optional -- //
                g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
                // -- Optional -- //
                g.DrawImage(image,
                    FromCameraPictureBox.Width - image.Width,  // to right
                    FromCameraPictureBox.Height - image.Height, // to bottom
                    image.Width,
                    image.Height);
            }

       }
       loadimage = false;
    }

现在我想从按钮触发 paintevent:

void TestButtonClick(object sender, EventArgs e)
    {

        loadimage = true;
    }

如何做到这一点？

Answer 1

我很困惑为什么这段代码工作起来很糟糕:

private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
    var g = e.Graphics;
    g.DrawImage(pictureBox1.Image, pictureBox1.Width - pictureBox1.Image.Width, pictureBox1.Height - pictureBox1.Image.Height);
}

编辑:

好的，现在可以了:

private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
    var image = Properties.Resources.SomeImage; //Import via Resource Manager
    //Don't use pictureBox1.Image property because it will
    //draw the image 2 times.
    //Make sure the pictureBox1.Image property is null in Deisgn Mode
    if (image != null)
    {
        var g = e.Graphics;
        // -- Optional -- //
        g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
        // -- Optional -- //
        g.DrawImage(image, 
            pictureBox1.Width - image.Width,  // to right
            pictureBox1.Height - image.Height, // to bottom
            image.Width,
            image.Height);
    }
}

更新:

Working :) But is there any possibility to use this code without PaintEventsArgs ? I was trying to add to my button flag and in paint (if (flag==true) then execute Your code, but it doesn't do anything - no drawing on picturebox1

那是因为 Paint 事件触发了一次。我们需要让它重绘。控件的默认重绘方法是 Refresh();

给你:

bool flag = false;
Bitmap image = null;
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
    if (flag && image != null)
    {
        var g = e.Graphics;
        // -- Optional -- //
        g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
        // -- Optional -- //
        g.DrawImage(image,
            pictureBox1.Width - image.Width,
            pictureBox1.Height - image.Height,
            image.Width,
            image.Height);
    }
}

private void button2_Click(object sender, EventArgs e)
{
    image = new Bitmap("someimage.png");
    flag = true;
    pictureBox1.Refresh(); //Causes it repaint.
}

//If you resize the form (and anchor/dock the picturebox) 
//or just resize the picturebox then you will need this:
private void pictureBox1_Resize(object sender, EventArgs e)
{
    pictureBox1.Refresh();
}