Texture2D渲染图像

Question

What is the fastest possible way to fill a Texture2D with image?

Under /Images/image.png I have the desired image.

My existing code just fills the texture with white color. How can I make it render the image?

Texture2D texture = new Texture2D(graphics.GraphicsDevice, this.Width, this.Height, false, SurfaceFormat.Color);
Color[] colors = new Color[this.Width * this.Height];
for (int j = 0; j < colors.Length; j++)
    colors[j] = color;
texture.SetData(colors);

Maybe I do it the wrong way but what is the easiest/fastest way to dynamicly display image on the screen?

Update

I changed my code to use ContentManager.

ContentManager contentManager = (Application.Current as App).Content;
Texture2D texture = contentManager.Load<Texture2D>("/Images/block.png");

contentManager.Load<Texture2D>(@"Images/block.png")

throws "File not found".

contentManager.Load<Texture2D>(@"/Images/block.png")

throws "Error loading "\\Images\\block.png". Cannot open file."

Answer 1

The easiest possible way is to just rely on the content pipeline as suggested.

When you create your XNA project, you should have two projects: MyGame, and MyGame (Content). Right click on the Content and select "Add Files". This will allow you to import images that can easily be pathed and get compiled into a .xnb format. I believe this is intended to accelerate things a little.

Once you've done that, you need a ContentManager object. Ideally you will use Content from your game class - which is already set up for you. But you can create one with:

ContentMananger content = new ContentManager(Services, "Content");

Where Services is from your game class (or an IServiceProvider with a GraphicsDeviceService ). The second argument is the root directory of your content folder.

Which will allow you to load arbitrary data formats from the content pipeline via:

content.Load<Texture2D>("myTexture");

(Note that you do not include the file extension.)

For ease, I suggest you make an "Images" folder in the Content project as you will have a large number of resources eventually and it makes it easier to organize. You could also have an SFX, Music, XML, etc, folders to handle all the data types your game will need.

So you'd do:

Texture2D myTexture = content.Load<Texture2D>("images/myTexture");
SpriteBatch spriteBatch = new SpriteBatch(graphics.GraphicsDevice);

(Note that these objects obviously need to be visible at the class scope). This would occur in your Initialization code for loading files.

After that, you would use the Draw method to actually draw the sprite

public override void Draw(SpriteBatch spriteBatch)
{
   spriteBatch.Begin();
   spriteBatch.Draw(myTexture, new Vector2(320, 240), Color.White);
   spriteBatch.End();
}

And your sprite is magically drawn.

What you're doing is essentially programmatically defining an image and then drawing it. While they has applications at points, probably not what you're looking for.

Answer 2

If you're trying to load an image at runtime, you can use this piece of code:

string file = @"Content/images/1.png"; // @ sign is to treat '/' as a character, not a control symbol
FileStream fs = new FileStream(file, FileMode.Open);
Texture2D texture = Texture2D.FromStream(GraphicsDevice, fs);
fs.Dispose();

…And then just use texture like so:

spritebatch.Draw(texture, new Vector2(123, 456), Color.White);

To use FileStream you may need to add using System.IO; in your game class.

This method is not considered standard practice, it may lead to problems with alpha channel, and to fix them you'll need to use a different alpha blending state. You can find more on that in this question .

Answer 3

If you're not using the content pipeline to add the texture, use Texture2D.FromStream() :

FileInfo imageFile = new FileInfo("Images\\image.png");
Texture2D image = Texture2D.FromStream(GraphicsDevice, imageFile.OpenRead());

If you're loading a lot of textures, you might want to dispose them when you don't need them anymore .