小编use*_*443的帖子

我将如何创建具有核心动画的图像序列.我想要:

添加image1 1秒钟然后删除图像

添加image2 2秒钟然后删除图像

添加image1 3秒钟然后删除

    CGImageRef image1 = [self getImage1];
    CALayer *image1Layer = [CALayer layer];
    image1Layer.bounds = CGRectMake(0, 0, 480, 320);
    image1Layer.position = CGPointMake(0, 0);
    image1Layer.contents = (id)image1;


    CABasicAnimation *animation1 = [CABasicAnimation animationWithKeyPath:@"animation"];
    animation1.repeatCount = 0; 
    animation1.duration = 2.0;
    animation1.removedOnCompletion = YES; // i would like to remove image here
    animation1.beginTime = AVCoreAnimationBeginTimeAtZero; 
    [image1Layer addAnimation:animation1 forKey:nil];

上面的代码添加了一个图像但不删除它.

干杯

我正在构建一个iphone应用程序并使用c ++并且无法检查指针是否为空.

IMyInterface* myInterface;

if ( !myInterface ){                         //doesn't work
     myInterfacee->doSometing(); 
}

if ( myInterface != 0 ) {                    //doesn't work 
     myInterfacee->doSometing(); 
}

if ( myInterface != NULL ){                  //doesn't work
     myInterfacee->doSometing(); 
}

if ( myInterface != ( myInterface* )0 ) {    //doesn't work 
     myInterfacee->doSometing(); 
}

如果myInterface设置或未设置,它仍会进入每个语句并给我

程序接收信号:"EXC_BAD_ACCESS".

我如何检查myInterface是否为空

我正在尝试在JavaScript中检索服务器控件.出于测试目的,我从页面加载事件调用JavaScript函数.

protected void Page_Load(object sender, EventArgs e){
    ClientScript.RegisterClientScriptBlock(GetType(), "js", "confirmCallBack();", true);
}

我的JavaScript功能是

function confirmCallBack() {
    var a = document.getElementById('<%= Page.Master.FindControl("PlaceHolderContent").FindControl("Button1").ClientID %>');
    var b = document.getElementById('<%=Button1.ClientID%>');
}

我的问题是a和b都返回null.即使我查看页面源,也会返回正确的ClientID.

我应该补充说我正在使用母版页.

有任何想法吗.

我使用以下算法来检测肤色,但它在不同的光照条件下不能很好地工作.任何人都可以提供任何建议,如何改进它或建议更好的方法

R > 95 AND G > 40 AND B > 20 AND
max{R, G, B} – min{R, G, B} >15 AND
|R – G| > 15 AND
R > G AND R > B
OR
R > 220 AND G > 210 AND B > 170 AND
|R – G| <= 15 AND
R > B AND G > B

http://softexpert.wordpress.com/2007/10/17/skin-color-detection/

干杯

无论如何,我可以在没有继承的情况下访问类中的受保护变量.

class ClassA{
  protected:
    int varA; 
};

class ClassB{
  protected:
    ClassA objectA;

};


ClassB theMainObject;

我想通过theMainObject访问varA.

我试图在自定义参数的接口中指定一个事件.我需要将event参数作为一个对象.我试图尽可能地删除以下代码.我目前收到以下错误.

ArgumentNullException: Argument cannot be null.
Parameter name: obj
LittleObject.IObject.add_ChangeEvent (System.EventHandler`1 value) 
(at LittleObject.cs line : [where the comment is])

码

public class ChangeEventArgs : EventArgs {
    public ChangeEventArgs(SomeClass c){ someClass = c;}
    public SomeClass someClass;
}


public interface IObject {
    void OnChangeEvent(ChangeEventArgs e);
    event EventHandler<ChangeEventArgs> ChangeEvent;
}


public class LittleObject : IObject{    

    public event EventHandler<ChangeEventArgs> ChangeEvent;

    public fireEvent(){
        OnChangeEvent(new ChangeEventArgs(new SomeClass()));
    }

    event EventHandler<ChangeEventArgs> IObject.ChangeEvent{
        add{                                // error here
            lock (ChangeEvent) {
                ChangeEvent += value;
             }
        }
        remove{
            lock …

我已经尝试过解除UIImagePickerController的每一个变种都没有运气.我究竟做错了什么.

- (IBAction)choosePhoto
{
    self.picker = [[UIImagePickerController alloc] init];
    self.picker.delegate = self;
    self.picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    [self presentModalViewController:self.picker animated:YES];

}

- (void)imagePickerControllerDidCancel:(UIImagePickerController *)imagePicker
{
    NSLog(@"dismiss image picker");
    [self dismissModalViewControllerAnimated:NO];
    [[self.picker parentViewController] dismissModalViewControllerAnimated:NO];
    [self.presentedViewController dismissModalViewControllerAnimated:NO];
    [self.presentingViewController dismissModalViewControllerAnimated:NO];
     // And every other way i could think of
}

- (void)imagePickerController:(UIImagePickerController *)imagePicker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    .. same stuff here
}

我试图从父,祖父母,navigationController和根控制器呈现选择器,没有任何作用.我做什么我不能解雇ImagePickerController.

请注意每次都会调用log语句.

干杯

我试图将数组复制到矢量,但是,当数据被复制到矢量时,它与原始数组的数据不同.

int arraySize = 640000;

std::vector<unsigned char> vector_buffer;
unsigned char buffer[arraySize];

populateArray(&buffer);

for(int i = 0; i < arraySize; i++)
     cout << buffer[i];  // this prints out data


std::copy ( buffer, buffer + arraySize, std::back_inserter(vector_buffer)); 


for(int i = 0; i < arraySize; i++)
     cout << vector_buffer[i];  // this prints out different data   

数据似乎以某种方式被压缩.将数组复制到向量的任何方法都会做同样的事情.

我用它来创建图像视频.如果我使用数组数据一切都很好,但如果我使用矢量数据它不起作用.

任何帮助将受到高度赞赏.

干杯

我使用glReadPixels抓取我的opengl场景的屏幕截图,然后在IOS 4上使用AVAssetWriter将它们转换为视频.我的问题是我需要将alpha通道传递给视频,该视频只接受kCVPixelFormatType_32ARGB和glReadPixels检索RGBA.所以基本上我需要一种方法将我的RGBA转换为ARGB,换句话说,首先放置alpha字节.

int depth = 4;
unsigned char buffer[width * height * depth];  
glReadPixels(0,0,width, height, GL_RGBA, GL_UNSIGNED_BYTE, &buffer);

CGDataProviderRef ref = CGDataProviderCreateWithData(NULL, &buffer), width*height*depth, NULL );

CGBitmapInfo bitmapInfo = kCGBitmapByteOrderDefault | kCGImageAlphaPremultipliedLast;

CGImageRef image = CGImageCreate(width, height, 8, 32, width*depth, CGColorSpaceCreateDeviceRGB(), bitmapInfo, ref, NULL, true, kCGRenderingIntentDefault);

UIWindow* parentWindow = [self window];

NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithBool:YES], kCVPixelBufferCGImageCompatibilityKey, [NSNumber numberWithBool:YES], kCVPixelBufferCGBitmapContextCompatibilityKey, nil];

CVPixelBufferRef pxbuffer = NULL;
CVReturn status = CVPixelBufferCreate(kCFAllocatorDefault, width, height, kCVPixelFormatType_32ARGB, (CFDictionaryRef) options, &pxbuffer);

NSParameterAssert(status == kCVReturnSuccess);
NSParameterAssert(pxbuffer …

我在opengl es 2.0中的简单方块上渲染png,但是当我尝试在正方形后面绘制一些东西时,我已经绘制了我的顶部正方形中的透明区域呈现与背景相同的颜色.

我在每个渲染调用的开头调用它们.

glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glEnable(GL_DEPTH_TEST);
glEnable (GL_BLEND); 
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

我有一个SQL Server数据库,我想定义一个查询,该查询仅根据int列中的前两个数字返回结果.

就像是:

SELECT * FROM myTable WHERE myIntColumn = 13% 

因此,将返回包含13,133,134和1380的任何行

嗨,我正在尝试生成一个具有脱机访问权限且不会过期的Facebook访问令牌.

我们目前正在使用生成令牌

https://graph.facebook.com/oauth/authorize?type=user_agent&client_id=OurAppId&redirect_uri=http://OurSite.com&scope=read_stream,offline_access

产生以下内容

http://OurSite.com/#access_token=BWLjKqmm5I4dBAJUoJsbrZBMjqUTYd5oUVKdMDf0nyZBkBMnl62F5lFPqliU4cfAaI9vHjwhfgpsidjw5zrBfg4M5RftQcYHkD2rf3rCmsfd4vyxW1SPkg1bfUS3NuY2MwwhUGD159LztlpgkjSunVwf8LZA70NoefhRt1fhYPZCpSJ35gjgs6SxHwZDZD&expires_in=5500

但这很快到期了.Graph Explorer中的字段也不是很明显.

我们如何生成具有未过期的脱机访问权限的令牌

干杯