c# - from - Cargue una imagen de una url en un PictureBox

open image c#

Question

Quiero cargar una imagen en un PictureBox . Esta es la imagen que quiero cargar: http://www.gravatar.com/avatar/6810d91caff032b202c50701dd3af745?d=identicon&r=PG

¿Cómo hago esto?

Answer 1

El método incorporado PictureBox.Load (cadena URL) "establece el ImageLocation en la URL especificada y muestra la imagen indicada". (Desde .NetFramework 2)

Answer 2

Esta es la solución que uso. No recuerdo por qué no podía usar los métodos de PictureBox.Load. Estoy bastante seguro de que es porque quería escalar y centrar correctamente la imagen descargada en el control PictureBox. Si no recuerdo mal, todas las opciones de escalado en PictureBox estirarán la imagen o cambiarán el tamaño del PictureBox para que se ajuste a la imagen. Quería una imagen con una escala y centrada en el tamaño que configuré para PictureBox.

Ahora, solo necesito hacer una versión asíncrona ...

Aquí están mis métodos:

 #region Image Utilities
/// <summary>
/// Loads an image from a URL into a Bitmap object.
/// Currently as written if there is an error during downloading of the image, no exception is thrown.
/// </summary>
/// <param name="url"></param>
/// <returns></returns>
public static Bitmap LoadPicture(string url)
{
System.Net.HttpWebRequest wreq;
System.Net.HttpWebResponse wresp;
Stream mystream;
Bitmap bmp;
bmp = null;
mystream = null;
wresp = null;
try
{
wreq = (System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create(url);
wreq.AllowWriteStreamBuffering = true;
wresp = (System.Net.HttpWebResponse)wreq.GetResponse();
if ((mystream = wresp.GetResponseStream()) != null)
bmp = new Bitmap(mystream);
}
catch
{
// Do nothing...
}
finally
{
if (mystream != null)
mystream.Close();
if (wresp != null)
wresp.Close();
}
return (bmp);
}
/// <summary>
/// Takes in an image, scales it maintaining the proper aspect ratio of the image such it fits in the PictureBox''s canvas size and loads the image into picture box.
/// Has an optional param to center the image in the picture box if it''s smaller then canvas size.
/// </summary>
/// <param name="image">The Image you want to load, see LoadPicture</param>
/// <param name="canvas">The canvas you want the picture to load into</param>
/// <param name="centerImage"></param>
/// <returns></returns>
public static Image ResizeImage(Image image, PictureBox canvas, bool centerImage )
{
if (image == null || canvas == null)
{
return null;
}
int canvasWidth = canvas.Size.Width;
int canvasHeight = canvas.Size.Height;
int originalWidth = image.Size.Width;
int originalHeight = image.Size.Height;
System.Drawing.Image thumbnail =
new Bitmap(canvasWidth, canvasHeight); // changed parm names
System.Drawing.Graphics graphic =
System.Drawing.Graphics.FromImage(thumbnail);
graphic.InterpolationMode = InterpolationMode.HighQualityBicubic;
graphic.SmoothingMode = SmoothingMode.HighQuality;
graphic.PixelOffsetMode = PixelOffsetMode.HighQuality;
graphic.CompositingQuality = CompositingQuality.HighQuality;
/* ------------------ new code --------------- */
// Figure out the ratio
double ratioX = (double)canvasWidth / (double)originalWidth;
double ratioY = (double)canvasHeight / (double)originalHeight;
double ratio = ratioX < ratioY ? ratioX : ratioY; // use whichever multiplier is smaller
// now we can get the new height and width
int newHeight = Convert.ToInt32(originalHeight * ratio);
int newWidth = Convert.ToInt32(originalWidth * ratio);
// Now calculate the X,Y position of the upper-left corner
// (one of these will always be zero)
int posX = Convert.ToInt32((canvasWidth - (image.Width * ratio)) / 2);
int posY = Convert.ToInt32((canvasHeight - (image.Height * ratio)) / 2);
if (!centerImage)
{
posX = 0;
posY = 0;
}
graphic.Clear(Color.White); // white padding
graphic.DrawImage(image, posX, posY, newWidth, newHeight);
/* ------------- end new code ---------------- */
System.Drawing.Imaging.ImageCodecInfo[] info =
ImageCodecInfo.GetImageEncoders();
EncoderParameters encoderParameters;
encoderParameters = new EncoderParameters(1);
encoderParameters.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality,
100L);
Stream s = new System.IO.MemoryStream();
thumbnail.Save(s, info[1],
encoderParameters);
return Image.FromStream(s);
}
#endregion

Aquí está el requerido incluye. (Algunos pueden ser necesarios por otro código, pero todos incluidos para estar seguros)

using System.Windows.Forms;
using System.Drawing.Drawing2D;
using System.IO;
using System.Drawing.Imaging;
using System.Text.RegularExpressions;
using System.Drawing;

Cómo lo uso generalmente:

 ImageUtil.ResizeImage(ImageUtil.LoadPicture( "http://someurl/img.jpg", pictureBox1, true);

Answer 3

Prueba esto:

var request = WebRequest.Create("http://www.gravatar.com/avatar/6810d91caff032b202c50701dd3af745?d=identicon&r=PG");
using (var response = request.GetResponse())
using (var stream = response.GetResponseStream())
{
pictureBox1.Image = Bitmap.FromStream(stream);
}

Answer 4

yourPictureBox.ImageLocation = "http://www.gravatar.com/avatar/6810d91caff032b202c50701dd3af745?d=identicon&r=PG"