小编ska*_*red的帖子

在我们的项目中,我们需要存储一些对象(例如User),并且User类必须有一个验证标志(setOutdated和isOutdated等方法)

有时,我们的User对象可能为null,但在这种情况下必须可以访问验证标志.可以从User类中提取这些方法,但由于语义的原因,该字段和方法必须位于该类中.

我发现了一些关于Null Object模式的文章(像这样),我想知道 - 是否可以创建Null Object(作为模式),它可以存储多个状态,如null过时,null不过时,不过时和过时不是没有过时的.

PS:如果在我的类中引入"过时"字段,则很难清除对象而不是将其设置为null

在我的应用程序中,我需要在设备充电时禁用显示器电源.Developer Menu中有一个选项可以禁用它,因此我可以发送Intent以供用户启用它.

我也发现了有关PowerManager和WakeLocks的信息,但我认为它适用于警报.我必须处理,是设备充电.

有什么更好的,还是有另一种方法可以做到这一点？

在我的代码中,我正在做这样的事情:

public void doStuff() {
    Bitmap scaledBitmap = decodeFileAndResize(captureFile);
    saveResizedAndCompressedBitmap(scaledBitmap);

    Bitmap rotatedBitmap = convertToRotatedBitmap(scaledBitmap);
    driverPhoto.setImageBitmap(rotatedBitmap);

    if (rotatedBitmap != scaledBitmap) {
        scaledBitmap.recycle();
        scaledBitmap = null;
        System.gc();
    }
}

private Bitmap convertToRotatedBitmap(Bitmap scaledBitmap) throws IOException {
    ExifInterface exifInterface = new ExifInterface(getCaptureFilePath());
    int exifOrientation = exifInterface.getAttributeInt(ExifInterface.TAG_ORIENTATION, 0);
    float orientationDegree = getRotationDegree(exifOrientation);
    Matrix rotateMatrix = new Matrix();
    rotateMatrix.postRotate(orientationDegree);

    return Bitmap.createBitmap(scaledBitmap, 0, 0, scaledBitmap.getWidth(), scaledBitmap.getHeight(), rotateMatrix, true);
}

一切正常,但是当我发表评论时,if (rotatedBitmap != scaledBitmap) {我有一个关于使用再生Bitmap的错误.

Android是否会在每次Bitmap.createBitmap调用时创建新的Bitmap ,如何避免位图之间的比较？

我让Activity在singleTop模式和C2DM接收器中运行.在某些通知中,我需要运行该活动,并以这种方式执行:

Intent activity = new Intent(context, klass);
activity.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TOP);
context.startActivity(activity);

当活动如果背景(例如之前按下Home按钮),一切正常.但是,当我按下电源按钮关闭屏幕时,无法通知运行活动有关某些更改(onNewIntent从未调用过).

如何通知有关通知的运行活动？

我有一个看起来像这样的课:

export module GameModule {
    export class Game {
        private boardContainer: HTMLElement;
        private board: number[][];

        constructor (container: HTMLDivElement) {
            this.boardContainer = container;
            this.board = [[0, 0, 0], [0, 0, 0], [0, 0, 0]];

            this.drawGrid();
        }

        drawGrid() {

        }
    }
}

和主要应用:

import GameModule = module("./GameModule");

window.onload = () => {
    new GameModule.GameModule.Game(<HTMLDivElement> document.getElementById('content'));
};

但是当我尝试编译代码时,我遇到了错误:

>tsc --module amd app.tss
app.tss(1, 27): The name '"./GameModule"' does not exist in the current scope
app.tss(1, 27): A module cannot be aliased to a …

我有以下方法:

public <T> execute(HttpRequest request) {
   ...
   // in parseAs i have to pass Class<T> how can I instantiate it from T?
   request.execute().parseAs(classT);
}

PS:parseAs是来自谷歌http客户端库的方法.

我有一个应用程序来处理从库中选择的图片.但ICS上有这样的堆栈跟踪崩溃:

java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1, result=-1, Intent { dat=content://com.google.android.gallery3d.provider/picasa/item/5629933319233370946 }} to activity {com.myexample/com.myexample.activities.UserProfileActivity}: java.lang.NullPointerException
at android.app.ActivityThread.deliverResults(ActivityThread.java:2980)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:3023)
at android.app.ActivityThread.access$1100(ActivityThread.java:123)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1177)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4424)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:787)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:554)
at dalvik.system.NativeStart.main(Native Method) Caused by: java.lang.NullPointerException
at java.io.File.fixSlashes(File.java:185)
at java.io.File.(File.java:134)
at com.jettaxi.activities.UserProfileActivity.onActivityResult(SourceFile:316)
at android.app.Activity.dispatchActivityResult(Activity.java:4649)
at android.app.ActivityThread.deliverResults(ActivityThread.java:2976)
... 11 more

我发现了一些关于这种bug的信息,但是我可以避免这种情况吗？

编辑:我的代码:

private void getImageFromGallery() {
        Intent galleryIntent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.INTERNAL_CONTENT_URI);
        startActivityForResult(galleryIntent, GALLERY_PIC_REQUEST);
}

@Override
protected void onActivityResult(int requestCode, int …

我想用D3创建具有预定义深度的树.

有没有办法在树生成之前设置深度？

最近我在我的Fedora 19上将我的Java版本升级到了7u40.之后我在我当前的JavaFX项目运行期间开始出现了一个令人讨厌的错误:

[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.929s
[INFO] Finished at: Wed Oct 16 17:36:05 CEST 2013
[INFO] Final Memory: 11M/155M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal com.zenjava:javafx-maven-plugin:2.0:run (default-cli) on project browser: Execution default-cli of goal com.zenjava:javafx-maven-plugin:2.0:run failed: An API incompatibility was encountered while executing com.zenjava:javafx-maven-plugin:2.0:run: java.lang.NoSuchMethodError: org.apache.maven.execution.MavenSession.getRepositorySession()Lorg/sonatype/aether/RepositorySystemSession;
[ERROR] -----------------------------------------------------
[ERROR] realm =    plugin>com.zenjava:javafx-maven-plugin:2.0
[ERROR] strategy = org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy
[ERROR] urls[0] = file:/home/sk_/.m2/repository/com/zenjava/javafx-maven-plugin/2.0/javafx-maven-plugin-2.0.jar
[ERROR] urls[1] = file:/home/sk_/.m2/repository/org/twdata/maven/mojo-executor/2.0/mojo-executor-2.0.jar
[ERROR] urls[2] = file:/home/sk_/.m2/repository/org/sonatype/aether/aether-util/1.7/aether-util-1.7.jar
[ERROR] urls[3] = file:/home/sk_/.m2/repository/org/codehaus/plexus/plexus-interpolation/1.14/plexus-interpolation-1.14.jar
[ERROR] urls[4] …

我正在尝试使用客户端证书创建Web应用程序,以编程方式生成.我的主要问题是:我已将生成的.p12密钥库添加到我的Web浏览器,但它不会将证书发送到服务器.

浏览器如何理解它应该使用哪个x509证书？是否可以在Firefox的Chrome中调试SSL？

我有一个带有接口的DLL

struct modeegPackage
{
    uint8_t     version;    // = 2
    uint8_t     count;      // packet counter. Increases by 1 each packet
    uint16_t    data[6];    // 10-bit sample (= 0 - 1023) in big endian (Motorola) format
    uint8_t     switches;   // State of PD5 to PD2, in bits 3 to 0
};

__declspec(dllexport) void __cdecl initSerial();

__declspec(dllexport) void __cdecl closeSerialPort();

__declspec(dllexport) struct modeegPackage __cdecl getPackage();

和C＃适配器

class EEGCommunication
{
    [StructLayout(LayoutKind.Sequential)]
    public struct modeegPackage
    {

        /// unsigned char
        public byte version;

        /// unsigned char
        public byte …

今天我发现了一些有趣的图书馆--ActiveJDBC.它提供了类似RoR的ActiveRecord接口,我正在考虑更换Hibernate,但是有一个问题 - ActiveJDBC可以处理真正大的查询和结果吗？在任何应用程序中使用它而不是Hibernate是否聪明？

我正在尝试Objective C用例子学习,现在我坚持以下问题.我有一个代码:

#import <UIKit/UIKit.h>
#import <MapKit/MapKit.h>

@interface ViewController :  UIViewController <MKMapViewDelegate> {
IBOutlet MKMapView *mapView;

MKPointAnnotation* startPoint;
MKPointAnnotation* endPoint;

double startPointLat;
double startPointLon;
double endPointLat;
double endPointLon;
}
@property (strong, nonatomic) IBOutlet MKMapView *mapView;
- (IBAction)findPressed:(id)sender;

@end

并实施:

- (void)viewDidLoad
{
[super viewDidLoad];
self.mapView.delegate = self;

// Add an annotation
startPoint = [[MKPointAnnotation alloc] init];
startPoint.coordinate = CLLocationCoordinate2DMake(0, 0);
startPoint.title = @"Start point";

endPoint = [[MKPointAnnotation alloc] init];
endPoint.coordinate = CLLocationCoordinate2DMake(10, 10);
endPoint.title = @"End point";

startPointLat = …