我們在一些專案中可能需要截圖儲存功能（特別是AR的一些專案），將截下來的圖儲存的相簿中，從而實現分享功能。下面就Android和IOS說一下他們是如何將圖片儲存到本地圖冊的。

關於安卓端，儲存到相簿方法很簡單，就是也路徑的問題，具體方法如下：

public class takephoto : MonoBehaviour
{
    private int i = 0;
    //UI
    public GameObject[] btn;
    //儲存路徑
    private string Path_save;
    //讀取路徑
    private string Path_read;
    private
 
 string filepath;
    private string destination;
    void Start()
    {
        filepath = Application.persistentDataPath + "/test.txt";
    }
    void OnClick()
    {
        StartCoroutine(getTexture2d());
    }
    IEnumerator getTexture2d()
    {
        //隱藏UI
        for (int j = 0; j < btn.Length; j++)
        {
            btn[j].GetComponentInChildren<UISprite>().enabled = false
 
;
        }
        //截圖操作
        yield return new WaitForEndOfFrame();
        Texture2D t = new Texture2D(Screen.width, Screen.height,TextureFormat.RGB24,false);
        //顯示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();

        //獲取系統時間
        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);
        //記錄每一個截圖名字
        StreamWriter sw;
        FileInfo ft = new FileInfo(filepath);
        if (!ft.Exists)
        {
            sw = ft.CreateText();
        }
        else
        {
            sw = ft.AppendText();
        }
        sw.WriteLine(filename);
        sw.Close();
        sw.Dispose();
        //應用平臺判斷，路徑選擇
        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;
       
        }
        //儲存檔案
        File.WriteAllBytes(Path_save, bytes);
    }

}

其中主要的就是安卓相簿的一個路徑問題，我是在相簿路徑下，新建了一個名叫ARphoto相簿，所有儲存下來的圖片都儲存在這個相簿中，可以再相簿應用中檢視到這個相簿資料夾。

在IOS端儲存相簿是無法單獨在Unity中完成的。需要呼叫Xcode中的方法，關於Unity與Xcode之間的互動有什麼疑問的可以檢視我之前寫的 博文http://blog.csdn.net/hasion/article/details/43668229

其具體實現方法如下：

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中執行檔案如下：

#import "PhotoManager.h"
@implementation PhotoManager
- ( void ) imageSaved: ( UIImage *) image didFinishSavingWithError:( NSError *)error
          contextInfo: ( void *) contextInfo
{
    if (error != nil)
    {
        NSLog(@"有錯誤");
    }
    else
    {
        NSLog(@"儲存結束");
    }
}


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

大體執行流程就是這樣的，有什麼錯誤或者建議的地方，歡迎大家指正，謝謝！！！