Unity3d 截屏

#pragma strict
function Start () {}
function Update () {}
function ScreenImage(){
Application.CaptureScreenshot("Screenshot.png"); 
}

UIButton *button1 = [UIButton buttonWithType:UIButtonTypeRoundedRect];       
    [button1 setFrame:CGRectMake(0, 0, 30, 30)];  
    [button1 addTarget:self action:@selector(ScreenImage) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button1];

-(void)ScreenImage{  
    ///调取脚本函数
    UnitySendMessage("ARCamera","ScreenImage","");  
 //保存到相册
    NSFileManager *fileManager = [NSFileManager defaultManager];  
    NSArray *paths = NSSearchPathForDirectoriesInDomains( NSDocumentDirectory,                                                                          NSUserDomainMask, YES);  
    NSString *documentsDirectory = [paths objectAtIndex:0];  
    NSString *filePath2 = [documentsDirectory stringByAppendingPathComponent:@"Screenshot.png"];  
    UIImage *image = [UIImage imageWithContentsOfFile:filePath2];  
    UIImageWriteToSavedPhotosAlbum(image,nil, nil, nil);//保存
}