Unity 截屏功能（安卓、IOS）

我们在一些项目中可能需要截图保存功能（特别是AR的一些项目），将截下来的图保存的相册中，从而实现分享功能。下面就Android和IOS说一下他们是如何将图片保存到本地图册的。

关于安卓端，保存到相册方法很简单，就是也路径的问题，具体方法如下：

public class takephoto : MonoBehaviour
{
private int i = 0;
//UI
public GameObject[] btn;
//存储路径
private string Path_save;
//读取路径
private string Path_read;
private string filepath;
private string destination;
void Start()
{
filepath = Application.persistentDataPath + "/test.txt";
}
void OnClick()
{
StartCoroutine(getTexture2d());
}
IEnumerator getTexture2d()
{
//隐藏UI
for (int j = 0; j < btn.Length; j++)
{
btn[j].GetComponentInChildren<UISprite>().enabled = false;
}
//截图操作
yield return new WaitForEndOfFrame();
Texture2D t = new Texture2D(Screen.width, Screen.height,TextureFormat.RGB24,false);
//显示UI
for (int j = 0; j < btn.Length; j++)
{
btn[j].GetComponentInChildren<UISprite>().enabled = true;
}
t.ReadPixels(new Rect(0, 0, Screen.width, Screen.height), 0, 0, true);
byte[] bytes = t.EncodeToPNG();
t.Compress(true);
t.Apply();

//获取系统时间
System.DateTime now = new System.DateTime();
now = System.DateTime.Now;
string filename = string.Format("image{0}{1}{2}{3}.png", now.Day, now.Hour, now.Minute, now.Second);
//记录每一个截图名字
StreamWriter sw;
FileInfo ft = new FileInfo(filepath);
if (!ft.Exists)
{
sw = ft.CreateText();
}
else
{
sw = ft.AppendText();
}
sw.WriteLine(filename);
sw.Close();
sw.Dispose();
//应用平台判断，路径选择
if (Application.platform == RuntimePlatform.Android)
{
string origin = Path_save;
destination = "/mnt/sdcard/DCIM/ARphoto";
if (!Directory.Exists(destination))
{
Directory.CreateDirectory(destination);
}
destination = destination + "/" + filename;
Path_save = destination;

}
//保存文件
File.WriteAllBytes(Path_save, bytes);
}

}

其中主要的就是安卓相册的一个路径问题，我是在相册路径下，新建了一个名叫ARphoto相册，所有保存下来的图片都保存在这个相册中，可以再图库应用中查看到这个相册文件夹。

在IOS端保存相册是无法单独在Unity中完成的。需要调用Xcode中的方法，关于Unity与Xcode之间的交互有什么疑问的可以查看我之前写的 博文http://blog.csdn.net/hasion/article/details/43668229

其具体实现方法如下：

public class TakePhoto : MonoBehaviour
{
[DllImport("__Internal")]
private static extern void _SavePhoto (string readaddr);

private string path_save;
private string path_read;
public GameObject _demoBtns;

void OnClick ()
{
this.GetComponentInChildren<UITexture> ().enabled = false;
_demoBtns.SetActive (false);

System.DateTime now = System.DateTime.Now;
string filename = string.Format ("image{0}{1}{2}{3}{4}{5}.png", now.Year, now.Month, now.Day, now.Hour, now.Minute, now.Second);
path_save = filename;
path_read = Application.persistentDataPath + "/" + path_save;

//set photomanager.cs
if (!string.IsNullOrEmpty (path_save)) {
PhotosManager.GetInstance ().PhotoPath = path_read;
}

StartCoroutine (SavePhoto ());
}

IEnumerator SavePhoto ()
{
yield return new WaitForSeconds (0.2f);
Application.CaptureScreenshot (path_save);
yield return new WaitForSeconds (0.5f);
this.GetComponentInChildren<UITexture> ().enabled = true;
_demoBtns.SetActive (true);

yield return new WaitForSeconds (1.2f);
_SavePhoto (path_read);

}
}

Xcode中执行文件如下：

#import "PhotoManager.h"
@implementation PhotoManager
- ( void ) imageSaved: ( UIImage *) image didFinishSavingWithError:( NSError *)error
contextInfo: ( void *) contextInfo
{
if (error != nil)
{
NSLog(@"有错误");
}
else
{
NSLog(@"保存结束");
}
}

void _SavePhoto(char *readAddr)
{
NSString *strReadAddr = [NSString stringWithUTF8String:readAddr];
UIImage *img = [UIImage imageWithContentsOfFile:strReadAddr];
NSLog(@"%@",[NSString stringWithFormat:@"w:%f, h:%f", img.size.width, img.size.height]);
NSLog(@"%@",[NSString stringWithFormat:@"%s",readAddr ]);
PhotoManager *instance = [PhotoManager alloc];
UIImageWriteToSavedPhotosAlbum(img, instance,
@selector(imageSaved:didFinishSavingWithError:contextInfo:), nil);
}

@end

大体执行流程就是这样的，有什么错误或者建议的地方，欢迎大家指正，谢谢！！！