[置顶] Unity截屏方法，在Unity中进行截屏。

今天我们讨论下Unity3D的截屏方法，总共有三种方式。

1、利用Unity自带的系统方式进行截屏：

Application.CaptureScreenshot("Screenshot.png");

2、利用Texture2D.ReadPixels()方法和Texture2D.EncodeToPng()方法进行截屏并保存数据，代码如下：

using System.IO;
using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
void Start() {
UploadPNG();
}
//开启一个携程进行截屏
IEnumerator UploadPNG()
{
//等待帧结束
yield return new WaitForEndOfFrame();
//获取到屏幕的宽高，进行全屏截图
int width = Screen.width;
int height = Screen.height;
Texture2D tex = new Texture2D(width, height, TextureFormat.RGB24, false);
tex.ReadPixels(new Rect(0, 0, width, height), 0, 0);
tex.Apply();
//将图片转成byte数据
byte[] bytes = tex.EncodeToPNG();
Destroy(tex);
//利用post方法将图片数据进行上传
WWWForm form = new WWWForm();
form.AddField("frameCount", Time.frameCount.ToString());
form.AddBinaryData("fileUpload", bytes);
WWW w = new WWW("http://localhost/cgi-bin/env.cgi?post", form);
yield return w;
if (w.error != null)
print(w.error);
else
print("Finished Uploading Screenshot");
}
}

3、针对某个相机进行截图，代码如下所示：

Texture2D CaptureCamera(Camera camera, Rect rect)
{
// 创建一个RenderTexture对象
RenderTexture rt = new RenderTexture((int)rect.width, (int)rect.height, 0);
// 临时设置相关相机的targetTexture为rt, 并手动渲染相关相机
camera.targetTexture = rt;
camera.Render();
//如果这样加上第二个相机，可以实现只截图某几个指定的相机一起看到的图像。
//camera2.targetTexture = rt;
//camera2.Render();

// 激活这个rt, 并从中中读取像素。
RenderTexture.active = rt;
Texture2D screenShot = new Texture2D((int)rect.width, (int)rect.height, TextureFormat.RGB24,false);
screenShot.ReadPixels(rect, 0, 0);// 注：这个时候，它是从RenderTexture.active中读取像素
screenShot.Apply();

// 重置相关参数，以使用camera继续在屏幕上显示
camera.targetTexture = null;
//camera2.targetTexture = null;
RenderTexture.active = null; // JC: added to avoid errors
GameObject.Destroy(rt);
// 最后将这些纹理数据，成一个png图片文件
byte[] bytes = screenShot.EncodeToPNG();
string filename = Application.dataPath + "/Screenshot.png";
System.IO.File.WriteAllBytes(filename, bytes);
Debug.Log(string.Format("截屏了一张照片: {0}", filename));

return screenShot;
}