我想要一個 recyclerview 只顯示一個數(shù)組，但在 arraylist 中有更多。必須顯示的那個不能總是相同的，但這將取決于某些百分比。例如：第一個數(shù)組有 20% 的機會，第二個 50% 和第三個 50% 也有。并隨機顯示一個。但是當(dāng)我刷新屏幕時它會改變。我想我應(yīng)該做的是為數(shù)組列表中的每個數(shù)組設(shè)置百分比，但我不知道該怎么做以及下一步該做什么。那是我的java文件。public class Comida extends AppCompatActivity implements Adaptador2.OnRecipeListener { private RecyclerView recyclerView1; List<Entidad2> listItems; Adaptador2 adaptor; private Entidad2 entidad1,entidad2,entidad3; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); requestWindowFeature(Window.FEATURE_NO_TITLE); getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); setContentView(R.layout.activity_comida); recyclerView1 = findViewById(R.id.lv_1); LinearLayoutManager layoutManager = new LinearLayoutManager(this); layoutManager.setOrientation(LinearLayoutManager.VERTICAL); recyclerView1.setLayoutManager(layoutManager); listItems = new ArrayList<>(); entidad1 = new Entidad2(R.drawable.calabacines_3, "Solomillo a la plancha", " 10 min.", 4, 20); entidad2 = new Entidad2(R.drawable.patatas_deluxe_especiadas_70523_300_150, "Entrecot", " 15 min.", 2, 50); entidad3 = new Entidad2(R.drawable.tomate, "Hamburguesa", " 2 min.", 5, 100); listItems.add(entidad1); listItems.add(entidad2); listItems.add(entidad3); adaptor = new Adaptador2(listItems, this); recyclerView1.setAdapter(adaptor); adaptor.notifyDataSetChanged(); pickEntidad(); } @Override public void OnRecipe(int priority) { if (priority == 20) { Intent in = new Intent(this, Solomillo.class); startActivity(in); } if (priority == 50) { Intent in = new Intent(this, Entrecot.class); startActivity(in); } }}
1 回答
三國紛爭
TA貢獻1804條經(jīng)驗 獲得超7個贊
我的理解是，您想以不同的顯示機會隨機顯示 Entidad 列表中的單個 Entidad 對象。
例如：在您的 Entidad 對象上創(chuàng)建一個名為 Priority 的整數(shù)字段。將第一個 Entidad 的優(yōu)先級設(shè)置為 50，第二個 200，第三個 350。創(chuàng)建以下方法以根據(jù)優(yōu)先級隨機選擇。（在創(chuàng)建它們后將 Entidad 對象的引用保存在主活動中。）
編輯：Entidad.java
public class Entidad {
private int imgFoto;
private String titulo;
private String tiempo;
private int ratingBar;
private int colorfondo;
private int priority;
public Entidad(int imgFoto, String titulo, String tiempo, int ratingBar, int colorfondo, int priority) {
this.imgFoto = imgFoto;
this.titulo = titulo;
this.tiempo = tiempo;
this.ratingBar = ratingBar;
this.colorfondo = colorfondo;
this.priority = priority;
}
public int getRatingBar() {
return ratingBar;
}
public int getPriority() {
return priority;
}
public int getImgFoto() {
return imgFoto;
}
public String getTitulo() {
return titulo;
}
public String getTiempo() {
return tiempo;
}
public int getRating() { return ratingBar; }
public int getColorfondo() {
return colorfondo;
}
}
編輯 2：使用 getEntidad()
public class Comida extends AppCompatActivity implements Adaptador.OnRecipeListener {
private RecyclerView recyclerView1;
List<Entidad> listItems;
Adaptador adaptor;
private Entidad entidad1,entidad2,entidad3;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_comida);
recyclerView1 = findViewById(R.id.lv_1);
LinearLayoutManager layoutManager = new
LinearLayoutManager(this);
layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
recyclerView1.setLayoutManager(layoutManager);
listItems = new ArrayList<>();
//Initialize entidad objects and keep references of them to use in pickEntidad() method
entidad1 = new Entidad(R.drawable.calabacines_3, "Solomillo a la plancha", " 10 min.", 4, R.drawable.color_carnes,50);
entidad2 = new Entidad(R.drawable.patatas_deluxe_especiadas_70523_300_150, "Entrecot", " 15 min.", 2, R.drawable.color_carnes,200);
entidad3 = new Entidad(R.drawable.tomate, "Hamburguesa", " 2 min.", 5, R.drawable.color_carnes,350);
listItems.add(entidad1);
listItems.add(entidad2);
listItems.add(entidad3);
adaptor = new Adaptador(listItems, this);
recyclerView1.setAdapter(adaptador);
adaptor.notifyDataSetChanged();
//Call pickEntidad() to randomly pick one entidad and show on the list
pickEntidad();
}
@Override
public void OnRecipe(int position) {
if (position == 0) {
Intent in = new Intent(this, Solomillo.class);
startActivity(in);
}
}
private void pickEntidad(){
//Generates random int value between 0-350
final int random = new Random().nextInt(351);
//get priorities from your created Entidad objects.
int priority1 = entidad1.getPriority();
int priority2 = entidad2.getPriority();
int priority3 = entidad3.getPriority();
listItems.clear()
//Pick one randomly depending on priority
if(random < priority1){
listItems.add(entidad1)
}else if(random < priority2){
listItems.add(entidad2)
}else if (random <= priority3){
listItems.add(entidad3)
}
//update your adapter
adaptor.notifyDataSetChanged()
}
}
每次您想刷新列表時，調(diào)用此 pickEntidad() 方法。不過，這是一種硬編碼方法，如果您有太多項目并且不知道優(yōu)先級值或范圍，它將毫無用處。您還可以通過生成 0-351 之間的整數(shù)來隨機設(shè)置項目優(yōu)先級。希望我能正確理解你的問題。
另外，不要給變量名加上大寫字母。將您的“適配器”變量更改為“適配器”
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