Combining two instantiate scripts (Unity 3D) - arrays

I need to combine the following scripts into one script containing two functions, one that instantiates the next prefab in the array and the other that instantiates the previous prefab in the array (it is a virtual tour app). Both should also destroy the current prefab. I could then call the functions via event triggers.
I have this code for the "next Prefab" script.
public GameObject[] Spheres;
int currentIndex = 0;
GameObject currentObject;
public Camera MainCamera;
void OnMouseDown()
{
if (Input.GetMouseButtonDown(0))
if (gameObject.tag == "ArrowNEXT")
{
Vector3 rayOrigin = MainCamera.ViewportToWorldPoint(new Vector3(0.1f, 0.1f, 0));
RaycastHit hit;
if (Physics.Raycast(rayOrigin, MainCamera.transform.forward, out hit))
{
if (hit.collider != null)
{
{
Destroy(currentObject);
currentIndex++;
if (currentIndex > Spheres.Length - 1) currentIndex = 0;
currentObject = Instantiate(Spheres[currentIndex]);
}
}
}
}
}
I need to combine it with the following:
using UnityEngine;
public class RayCastPrevFIX: MonoBehaviour
{
public GameObject[] Spheres;
int currentIndex = 0;
GameObject currentObject;
public Camera MainCamera;
void OnMouseDown()
{
if (Input.GetMouseButtonDown(0))
if (gameObject.tag == "ArrowPREV")
{
Vector3 rayOrigin = MainCamera.ViewportToWorldPoint(new Vector3(0.1f, 0.1f, 0));
RaycastHit hit;
if (Physics.Raycast(rayOrigin, MainCamera.transform.forward, out hit))
{
if (hit.collider != null)
{
{
Destroy(currentObject);
currentIndex--;
if (currentIndex < 0) currentIndex = Spheres.Length - 1;
currentObject = Instantiate(Spheres[currentIndex]);
}
}
}
}
}
}
How would I go about this? Any help is greatly appreciated.I have this so far:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class SphereSwap : MonoBehaviour
{
public GameObject[] Spheres;
int currentIndex = 0;
GameObject currentObject;
public Camera MainCamera;
void Next()
{
Destroy(currentObject);
currentIndex++;
if (currentIndex > Spheres.Length - 1) currentIndex = 0;
currentObject = Instantiate(Spheres[currentIndex]);
}
void Previous()
{
Destroy(currentObject);
currentIndex--;
if (currentIndex < 0) currentIndex = Spheres.Length - 1;
currentObject = Instantiate(Spheres[currentIndex]);
}
}

You're on the right path, but you could shorten the code as well as use one function for both cases to avoid boilerplate:
using UnityEngine;
public class SphereSwap : MonoBehaviour
{
public GameObject[] Spheres;
int currentIndex = 0;
GameObject currentObject;
public Camera MainCamera;
const string ArrowPrevTag = "ArrowPREV";
const string ArrowNextTag = "ArrowNEXT";
private void HandleClick(bool next)
{
if(Spheres == null || Spheres.Length == 0)
{
Debug.Log($"Spheres list is empty, nothing to swap.");
return;
}
Vector3 rayOrigin = MainCamera.ViewportToWorldPoint(new Vector3(0.1f, 0.1f, 0));
RaycastHit hit;
if (Physics.Raycast(rayOrigin, MainCamera.transform.forward, out hit))
{
if (hit.collider != null)
{
// destroy current sphere.
Destroy(currentObject);
// go next or previous.
currentIndex += next ? 1 : -1;
// circular clamp if overflow
if (currentIndex < 0)
currentIndex = Spheres.Length - 1;
else if (currentIndex >= Spheres.Length)
currentIndex = 0;
// finally do instantiate.
currentObject = Instantiate(Spheres[currentIndex]);
}
}
}
private void OnMouseDown()
{
if (Input.GetMouseButtonDown(0))
{
// 'CompareTag' is more efficient than gameobject.tag == "sometag"
if (gameObject.CompareTag(ArrowNextTag))
HandleClick(true);
else if (gameObject.CompareTag(ArrowPrevTag))
HandleClick(false);
}
}
}

Related

WPF list modification during iteration?

I'm trying to make a very simple game where the yellow ball bouncing back and fourth. If it collides with one of the moving blue squares, the square is supposed to disappear and a new one should appear (always 3 in the window) elsewhere. When my code reaches this part, all 3 squares disappear (then reappears as intended it is not a problem) and I just cant figure out why. It would be a huge help if somebody could run over my methods responsible for the problem. Thank you in advance.
So my timer_Tick method, responsible for every frame:
void timer_Tick(object sender, EventArgs e)
{
logic.MoveBall();
if (model.Enemy.Count<3)
{
logic.AddEnemy();
}
int iii = 0;
foreach (MyShape enemy in model.Enemy) //the whole thing from here is me trying to solve list modification during iteration
{
if (logic.MoveEnemy(enemy) == -1)
{
logic.MoveEnemy(enemy);
}
else iii = logic.MoveEnemy(enemy);
}
if (iii > -1)
{
for (int j = model.Enemy.Count - 1; j >= 0; j--)
{
if (j == model.Enemy.Count - iii)
{
model.Enemy.RemoveAt(j);
}
}
}
}
MoveEnemy: I try to decide whether there is collusion and if yes, then try to remove the given shape object (blue square). Because This whole method is in a foreach, I just save the removable element and forward it to timer_Tick
public int MoveEnemy(MyShape shape)
{
int i = 0;
int ii = -1;
if ((shape.Area.IntersectsWith(model.Ball.Area)))
{
i = 0;
foreach (var e in model.Enemy)
{
i++;
if (shape == e)
{
ii = i;
}
}
}
shape.ChangeX(shape.Dx);
shape.ChangeY(shape.Dy);
bool coll = false;
foreach (var e in model.Enemy)
{
if ((e.Area.IntersectsWith(shape.Area)) && (shape != e))
{
coll = true;
}
}
if (shape.Area.Left < 0 || shape.Area.Right > Config.Width-40 || coll)
{
shape.Dx = -shape.Dx;
}
if (shape.Area.Top < 0)
{
shape.Dy = -shape.Dy;
}
if (shape.Area.Bottom > Config.Height/2)
{
shape.Dy = -shape.Dy;
}
RefreshScreen?.Invoke(this, EventArgs.Empty);
return ii;
}
And finally AddEnemy:
public void AddEnemy()
{
rnd = new Random();
int r = rnd.Next(-300, 300);
model.Enemy.Add(new MyShape(Config.Width / 2+r, 0, 40, 40));
RefreshScreen?.Invoke(this, EventArgs.Empty);
}
List<T> (or IList and Enumerable) exposes some useful methods to compact code:
int itemIndex = list.IndexOf(item); // Gets the index of the item if found, otherwise returns -1
list.Remove(item); // Remove item if contained in collection
list.RemoveAll(item => item > 5); // Removes all items that satisfy a condition (replaces explicit iteration)
bool hasAnyMatch = list.Any(item => item > 5); // Returns true as soon as the first item satisfies the condition (replaces explicit iteration)
A simplified version, which should eliminate the flaw:
void timer_Tick(object sender, EventArgs e)
{
if (model.Enemy.Count < 3)
{
logic.AddEnemy();
}
logic.MoveBall();
model.Enemy.ForeEach(logic.MoveEnemy);
model.Enemy.RemoveAll(logic.IsCollidingWithBall);
}
public void AddEnemy()
{
rnd = new Random();
int r = rnd.Next(-300, 300);
model.Enemy.Add(new MyShape(Config.Width / 2 + r, 0, 40, 40));
RefreshScreen?.Invoke(this, EventArgs.Empty);
}
public bool IsCollidingWithBall(MyShape shape)
{
return shape.Area.IntersectsWith(model.Ball.Area);
}
public int MoveEnemy(MyShape shape)
{
shape.ChangeX(shape.Dx);
shape.ChangeY(shape.Dy);
bool hasCollision = model.Enemy.Any(enemy => enemy.Area.IntersectsWith(shape.Area)
&& enemy != shape);
if (hasCollision || shape.Area.Left < 0 || shape.Area.Right > Config.Width - 40)
{
shape.Dx = -shape.Dx;
}
if (shape.Area.Top < 0)
{
shape.Dy = -shape.Dy;
}
if (shape.Area.Bottom > Config.Height / 2)
{
shape.Dy = -shape.Dy;
}
RefreshScreen?.Invoke(this, EventArgs.Empty);
}

How do I repeat an action in c# to fix the jumping mechanism

I'm creating a basic 2D platformer game however the jumping mechanism will only run once and land directly afterwards. How do I loop this?
I tried detection collisions (from tag: Terrain) and this does help a lot however it's still not working correctly.
This is my code:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class PlayerController2D : MonoBehaviour
{
private Rigidbody2D rb2D;
private Vector2 velocity;
Vector2 xvelocity = new Vector2(10, 0);
Vector2 yvelocity = new Vector2(0, 10);
public float jumptime;
bool grounded = true;
bool jump = false;
void Start()
{
rb2D = GetComponent<Rigidbody2D>();
}
void Update()
{
if (Input.GetButton("Jump"))
{
jump = true;
}
}
private void FixedUpdate()
{
//Debug.Log(Input.GetAxisRaw("Vertical"));
if (left == true)
{
//Debug.Log("Left");
rb2D.MovePosition(rb2D.position + -xvelocity * Time.fixedDeltaTime);
}
if (right == true)
{
//Debug.Log("Right");
rb2D.MovePosition(rb2D.position + xvelocity * Time.fixedDeltaTime);
}
//if (jump == true && grounded == true)
//{
// jumptime -= Time.fixedDeltaTime;
// if (jumptime > 0)
// {
// rb2D.MovePosition(rb2D.position + yvelocity * Time.fixedDeltaTime);
// }
// if (jumptime <= 0)
// {
// jump = false;
// jumptime = 2;
// }
if (jump == true && grounded == true && jumptime > 0)
{
jumptime -= Time.fixedDeltaTime;
rb2D.MovePosition(rb2D.position + yvelocity * Time.fixedDeltaTime);
} else if (jumptime <= 0)
{
jump = false;
jumptime = 2f;
}
//if (Time.fixedDeltaTime >= 2)
//{
// jump = false;
// rb2D.MovePosition(rb2D.position + -yvelocity * Time.fixedDeltaTime);
//}
}
void OnCollisionExit2D(Collision2D other)
{
Debug.Log("No longer in contact with " + other.transform.name);
jump = true;
grounded = false;
}
void OnCollisionEnter2D(Collision2D collision)
{
if (collision.gameObject.tag == "Terrain")
{
Debug.Log("Landed");
jump = false;
grounded = true;
}
}
}
The expected outcome is that the action 'jump' will loop for ~1/1.5 seconds with a good height (vector2 yvelocity) so it will jump higher and will come down afterwards (thanks to the gravity from the Rigidbody (2D))
As stated in the comments I think the main issue is coming from this line of code.
if (jump == true && grounded == true && jumptime > 0)
It is much likely that one of those bool is not what you expect it to be. Anyway I suggest you to convert the line like so:
if (jump && grounded && jumptime > 0)
You do not need == true for booleans.
Anyway, to solve your question in an easier way, I would suggest you to use AddForce instead of move (because you're using a rigibody2d anyway).
rb2D.AddForce(Vector2.up * jumpForce, ForceMode2D.Impulse);
A small note about horizontal velocity. If you're using a rigibody it would be better to move it with the same rigidbody and not with the transform:
rb2D.MovePosition(rb2D.position + Vector2.left * xspeed * Time.fixedDeltaTime);
Your code will become:
public class PlayerController2D : MonoBehaviour
{
private Rigidbody2D rb2D;
private Vector2 velocity;
public float jumpForce = 5;
bool grounded = true;
void Start() { rb2D = GetComponent<Rigidbody2D>(); }
void Update()
{
if (Input.GetButton("Jump") && grounded)
rb2D.AddForce(Vector2.up * jumpForce, ForceMode2D.Impulse);
//calculate horizontal speed here
xspeed = ...;
}
private void FixedUpdate()
{
rb2D.MovePosition(rb2D.position + Vector2.left * xspeed * Time.fixedDeltaTime);
}
void OnCollisionExit2D(Collision2D other)
{
Debug.Log("No longer in contact with " + other.transform.name);
grounded = false;
}
void OnCollisionEnter2D(Collision2D collision)
{
if (collision.gameObject.tag == "Terrain")
{
Debug.Log("Landed");
grounded = true;
}
}
}

How to build a swipable intro screen?

A lot of apps have swipable intro screens - You know - those with the dots below which indicate the page one is currently viewing.
What would be the best way to create one in Codename One - a Container with snapToGrid?
I have my own implementation for this use case. There are two classes : TutoDialog which could be in your case the "intro screens" dialog and Caroussel with the dots indicator.
A tuto dialog has a title and some images in parameter. It automatically adjust the number of dots of the caroussel according to the number of images. For my use case, each image is a screenshot of my app with some advise. The tuto dialog contains 3 buttons to navigate between images (next/previous/finish).
public class Caroussel extends Container {
private final static Image CIRCLE = MainClass.getResources().getImage("circle-blue20.png");
private final static Image CIRCLE_EMPTY = MainClass.getResources().getImage("circle-empty-blue20.png");
private Label[] circles;
private int currentIndex = -1;
public Caroussel(int nbItems, boolean selectFirst) {
if (nbItems < 2 || nbItems > 50) {
throw new IllegalArgumentException("Can't create Caroussel component with nbItems<2 || nbItems>50 ! ");
}
this.circles = new Label[nbItems];
setLayout(new BoxLayout(BoxLayout.X_AXIS));
for (int i = 0; i < nbItems; i++) {
circles[i] = new Label("", CIRCLE_EMPTY);
add(circles[i]);
}
if (selectFirst) {
select(0);
}
}
public void select(int index) {
if (index >= 0 && index <= circles.length) {
if (currentIndex > -1) {
circles[currentIndex].setIcon(CIRCLE_EMPTY);
}
circles[index].setIcon(CIRCLE);
currentIndex = index;
repaint();
}
}
public void selectNext() {
if (currentIndex <= circles.length) {
select(currentIndex + 1);
}
}
public void selectPrevious() {
if (currentIndex >= 1) {
select(currentIndex - 1);
}
}}
And
public class TutoDialog extends Dialog {
private Caroussel caroussel = null;
public TutoDialog(String title, Image... images) {
if (images == null) {
return;
}
this.caroussel = new Caroussel(images.length, true);
setTitle(title);
setAutoAdjustDialogSize(true);
getTitleComponent().setUIID("DialogTitle2");
setBlurBackgroundRadius(8.5f);
Tabs tabs = new Tabs();
tabs.setSwipeActivated(false);
tabs.setAnimateTabSelection(false);
int px1 = DisplayUtil.getScaledPixel(800), px2 = DisplayUtil.getScaledPixel(600);
for (Image img : images) {
tabs.addTab("", new Label("", img.scaled(px1, px2)));
}
Container cButtons = new Container(new BorderLayout());
Button bSuivant = new Button("button.suivant");
Button bPrecedent = new Button("button.precedent");
Button bTerminer = new Button("button.terminer");
bPrecedent.setVisible(false);
bTerminer.setVisible(false);
bSuivant.addActionListener(new ActionListener<ActionEvent>() {
public void actionPerformed(ActionEvent evt) {
int currentInd = tabs.getSelectedIndex();
if (currentInd == 0) {
bPrecedent.setVisible(true);
}
if (currentInd + 1 <= tabs.getTabCount() - 1) {
if (caroussel != null)
caroussel.selectNext();
tabs.setSelectedIndex(currentInd + 1);
if (currentInd + 1 == tabs.getTabCount() - 1) {
bTerminer.setVisible(true);
bSuivant.setVisible(false);
cButtons.revalidate();
}
}
};
});
bPrecedent.addActionListener(new ActionListener<ActionEvent>() {
public void actionPerformed(ActionEvent evt) {
int currentInd = tabs.getSelectedIndex();
tabs.setSelectedIndex(currentInd - 1);
bSuivant.setVisible(true);
if (caroussel != null)
caroussel.selectPrevious();
if (currentInd - 1 == 0) {
bPrecedent.setVisible(false);
cButtons.revalidate();
}
};
});
bTerminer.addActionListener(new ActionListener<ActionEvent>() {
#Override
public void actionPerformed(ActionEvent evt) {
tabs.setSelectedIndex(0);
bPrecedent.setVisible(false);
bTerminer.setVisible(false);
bSuivant.setVisible(true);
if (caroussel != null)
caroussel.select(0);
TutoDialog.this.dispose();
}
});
cButtons.add(BorderLayout.WEST, bPrecedent).add(BorderLayout.CENTER, bSuivant).add(BorderLayout.EAST, bTerminer);
add(BoxLayout.encloseY(tabs, BoxLayout.encloseY(FlowLayout.encloseCenter(caroussel), cButtons)));
}
public static void showIfFirstTime(AbstractComponentController ctrl) {
if (ctrl == null) {
Log.p("Can't execute method showIfFirstTime(...) with null AbstractComponentController");
return;
}
String key = getKey(ctrl);
if (ctrl.getTutoDlg() != null && !Preferences.get(key, false)) {
Display.getInstance().callSerially(new Runnable() {
#Override
public void run() {
Preferences.set(key, true);
ctrl.getTutoDlg().show();
}
});
}
}
public static String getKey(AbstractComponentController ctrl) {
String key = "tuto" + ctrl.getClass().getSimpleName();
if (UserController.getCurrentUser() != null) {
key += "-" + UserController.getCurrentUser().getId();
}
return key;
}
public static boolean isAlreadyShown(AbstractComponentController ctrl) {
return Preferences.get(getKey(ctrl), false);
}
}
It's look like this :
OK - so that is my first attempt and I am pretty content with that:
private void showIntro() {
Display display = Display.getInstance();
int percentage = 60;
int snapWidth = display.getDisplayWidth() * percentage / 100;
int snapHeight = display.getDisplayHeight() * percentage / 100;
Dialog dialog = new Dialog(new LayeredLayout()) {
#Override
protected Dimension calcPreferredSize() {
return new Dimension(snapWidth, snapHeight);
}
};
Tabs tabs = new Tabs();
tabs.setTensileLength(0);
tabs.hideTabs();
int[] colors = {
0xc00000,
0x00c000,
0x0000c0,
0x909000,
0x009090,
};
for (int colorIndex = 0; colorIndex < colors.length; colorIndex++) {
Container containerElement = new Container() {
#Override
protected Dimension calcPreferredSize() {
return new Dimension(snapWidth, snapHeight);
}
};
Style style = containerElement.getAllStyles();
style.setBgTransparency(0xff);
style.setBgColor(colors[colorIndex]);
tabs.addTab("tab" + tabs.getTabCount(), containerElement);
}
int tabCount = tabs.getTabCount();
Button[] buttons = new Button[tabCount];
Style styleButton = UIManager.getInstance().getComponentStyle("Button");
styleButton.setFgColor(0xffffff);
Image imageDot = FontImage.createMaterial(FontImage.MATERIAL_LENS, styleButton);
for (int tabIndex = 0; tabIndex < tabCount; tabIndex++) {
buttons[tabIndex] = new Button(imageDot);
buttons[tabIndex].setUIID("Container");
final int tabIndexFinal = tabIndex;
buttons[tabIndex].addActionListener(aActionEvent -> tabs.setSelectedIndex(tabIndexFinal, true));
}
Container containerButtons = FlowLayout.encloseCenter(buttons);
dialog.add(tabs);
Button buttonWest = new Button("Skip");
buttonWest.setUIID("Container");
buttonWest.getAllStyles().setFgColor(0xffffff);
buttonWest.addActionListener(aActionEvent -> dialog.dispose());
Button buttonEast = new Button(">");
buttonEast.setUIID("Container");
buttonEast.getAllStyles().setFgColor(0xffffff);
buttonEast.addActionListener(aActionEvent -> {
int selectedIndex = tabs.getSelectedIndex();
if (selectedIndex < (tabs.getTabCount() - 1)) {
tabs.setSelectedIndex(selectedIndex + 1, true);
} else {
dialog.dispose();
}
});
Container containerSouth = BorderLayout.south(BorderLayout.centerAbsoluteEastWest(containerButtons, buttonEast, buttonWest));
Style styleContainerSouth = containerSouth.getAllStyles();
styleContainerSouth.setMarginUnit(
Style.UNIT_TYPE_DIPS,
Style.UNIT_TYPE_DIPS,
Style.UNIT_TYPE_DIPS,
Style.UNIT_TYPE_DIPS);
styleContainerSouth.setMargin(2, 2, 2, 2);
dialog.add(containerSouth);
SelectionListener selectionListener = (aOldSelectionIndex, aNewSelectionIndex) -> {
for (int buttonIndex = 0; buttonIndex < buttons.length; buttonIndex++) {
if (buttonIndex == aNewSelectionIndex) {
buttons[buttonIndex].getAllStyles().setOpacity(0xff);
} else {
buttons[buttonIndex].getAllStyles().setOpacity(0xc0);
}
}
buttonEast.setText((aNewSelectionIndex < (tabs.getTabCount() - 1)) ? ">" : "Finish");
buttonEast.getParent().animateLayout(400);
};
tabs.addSelectionListener(selectionListener);
dialog.addShowListener(evt -> {
buttonEast.getParent().layoutContainer();
selectionListener.selectionChanged(-1, 0);
});
Command command = dialog.showPacked(BorderLayout.CENTER, true);
}

downloadUrlToStorageInBackground in ImageList model for imageViewer downloads & overrides the image every time

class ImageList implements ListModel<Image> {
private int selection;
private Image[] images;
private EventDispatcher listeners = new EventDispatcher();
public ImageList() {
this.images = new EncodedImage[imageURLs.length];
}
public Image getItemAt(final int index) {
if (images[index] == null) {
images[index] = placeholderForTable;
Util.downloadUrlToStorageInBackground(imageURLs[index], "list" + index, (e) -> {
try {
images[index] = EncodedImage.create(Storage.getInstance().createInputStream("list" + index));
listeners.fireDataChangeEvent(index, DataChangedListener.CHANGED);
} catch (IOException err) {
err.printStackTrace();
}
});
}
return images[index];
}
public int getSize() {
return imageURLs.length;
}
public int getSelectedIndex() {
return selection;
}
public void setSelectedIndex(int index) {
selection = index;
}
public void addDataChangedListener(DataChangedListener l) {
listeners.addListener(l);
}
public void removeDataChangedListener(DataChangedListener l) {
listeners.removeListener(l);
}
public void addSelectionListener(SelectionListener l) {
}
public void removeSelectionListener(SelectionListener l) {
}
public void addItem(Image item) {
}
public void removeItem(int index) {
}
}
protected void postMenuForm(Form f) {
BusinessForumImagesConnection bfic = new BusinessForumImagesConnection();
bfic.businessForumImagesConnectionMethod(new ActionListener() {
#Override
public void actionPerformed(ActionEvent evt) {
if (bfic.response != null) {
for (int i = 0; i < imgLoop; i++) {
HashMap hm = (HashMap) bfic.response.get(i);
String imgUrl = (String) hm.get("imgUrl");
imageURLs[i] = imgUrl;
}
}
}
});
if (imageURLs != null) {
ImageList imodel = new ImageList();
ImageViewer iv = new ImageViewer(imodel.getItemAt(0));
iv.setImageList(imodel);
Container adsContainer = BoxLayout.encloseY(adsLabel, iv);
slideIndex = 0;
Runnable r = new Runnable() {
public void run() {
if (slideIndex < imodel.getSize()) {
nextImage = (Image) imodel.getItemAt(slideIndex);
if (nextImage != null) {
iv.setImage(nextImage);
}
slideIndex++;
} else {
slideIndex = 0;
}
}
};
if (uITimer == null) {
uITimer = new UITimer(r);
}
if (uITimer != null) {
uITimer.schedule(5000, true, f); //5 seconds
}
f.add(BorderLayout.SOUTH, adsContainer);
adsContainer.setLeadComponent(adsLabel);
adsLabel.addActionListener((e) -> {
showForm("BusinessForum", null);
});
}
}
I had used URLImage.createToStorage before but imageViewer didnt work properly so I have used ImageList model. But everytime the form is opened, it jst redownloads the imgs and overrides them in storage, that makes the app slower. How can I make sure if the image is already downloaded, it doesnt download it again and jst shows them in imgViewer? thankyou
The download method will always download regardless...
You need to check if the Storage file exists and if so load that.
See the WebServices/Dogs demo in the new kitchen sink: http://www.codenameone.com/blog/kitchensink-ii.html

Own CollectionView for paging, sorting and filtering

I've implemented my own CollectionView to bind a collection of data to a DataGrid in WPF.
The main goal was the pagination, which is working quite well.
I've written the following C# code:
public class SchemesCollectionView : CollectionView
{
private readonly IList<Scheme> innerList;
private readonly int itemsPerPage;
private int currentPage = 1;
public SchemesCollectionView(IList<Scheme> source, int itemsPerPage)
: base(source)
{
innerList = source;
this.itemsPerPage = itemsPerPage;
}
public override int Count
{
get { return itemsPerPage; }
}
public int CurrentPage
{
get { return currentPage; }
set
{
currentPage = value;
OnPropertyChanged(new PropertyChangedEventArgs("CurrentPage"));
OnPropertyChanged(new PropertyChangedEventArgs("FirstItemNumber"));
OnPropertyChanged(new PropertyChangedEventArgs("LastItemNumber"));
}
}
public int ItemsPerPage { get { return this.itemsPerPage; } }
public int PageCount
{
get
{
return (this.innerList.Count() + this.itemsPerPage - 1)
/ this.itemsPerPage;
}
}
public int LastItemNumber
{
get
{
var end = currentPage * itemsPerPage - 1;
end = (end > innerList.Count()) ? innerList.Count() : end;
return end + 1;
}
}
public int StartIndex
{
get { return (currentPage - 1) * itemsPerPage; }
}
public int FirstItemNumber
{
get { return ((currentPage - 1) * itemsPerPage) + 1; }
}
public override object GetItemAt(int index)
{
var offset = index % (ItemsPerPage);
var position = StartIndex + offset;
if (position >= innerList.Count)
{
position = innerList.Count - 1;
}
return innerList[position];
}
public void MoveToNextPage()
{
if (CurrentPage < PageCount)
{
CurrentPage += 1;
}
Refresh();
}
public void MoveToPreviousPage()
{
if (CurrentPage > 1)
{
CurrentPage -= 1;
}
Refresh();
}
public void MoveToFirstPage()
{
CurrentPage = 1;
Refresh();
}
public void MoveToLastPage()
{
CurrentPage = PageCount;
Refresh();
}
}
As mentioned, the pagination works very well. But I can't get the filtering and sorting work. When I add a custom filter to the Filter property, It gets completely ignored. The same with the sorting. I can see the arrows on the column headers after I clicked them, but the different sorting is not reflected within the DataGrid.
What I'm missing here? Hope someone can help.
As mentioned in this, you can take code from Silverlight and use that in WPF.
Paged Collection View in WPF
Here is a solution for filtering and paging using only the CollectionView class.
You just need to set the current page index and max items per page to fits your needs.
// obtenir la CollectionView
ICollectionView cvCollectionView = CollectionViewSource.GetDefaultView(this.Suivis);
if (cvCollectionView == null)
return;
// filtrer ... exemple pour tests DI-2015-05105-0
cvCollectionView.Filter = p_oObject => { return true; /* use your own filter */ };
// page configuration
int iMaxItemPerPage = 2;
int iCurrentPage = 0;
int iStartIndex = iCurrentPage * iMaxItemPerPage;
// déterminer les objects "de la page"
int iCurrentIndex = 0;
HashSet<object> hsObjectsInPage = new HashSet<object>();
foreach (object oObject in cvCollectionView)
{
// break if MaxItemCount is reached
if (hsObjectsInPage.Count > iMaxItemPerPage)
break;
// add if StartIndex is reached
if (iCurrentIndex >= iStartIndex)
hsObjectsInPage.Add(oObject);
// increment
iCurrentIndex++;
}
// refilter
cvCollectionView.Filter = p_oObject =>
{
return cvCollectionView.Contains(p_oObject) && hsObjectsInPage.Contains(p_oObject);
};

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