如何從arraylist中獲取字符串

Question

我有從ArrayList獲取值的問題。 Eveyrhing我可以做的是得到像這樣的價值：[Ljava.lang.string @....

你能幫助我嗎？我不知道mProductList.get(???)應該是什麼。我想從點擊項目分離值。

public class Activity1 extends Activity { 
private ListView lvProduct; 
private ProductListAdapter adapter; 
private List<Product> mProductList; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity1); 

    lvProduct = (ListView)findViewById(R.id.listView1); 

    mProductList = new ArrayList<>(); 
    mProductList.add(new Product(1, "Product_1", "Price", "Description")); 
    mProductList.add(new Product(2, "Product_2", "Price", "Description")); 
    mProductList.add(new Product(3, "Product_3", "Price", "Description")); 

    adapter = new ProductListAdapter(getApplicationContext(), mProductList); 
    lvProduct.setAdapter(adapter); 

    lvProduct.setOnItemClickListener(new AdapterView.OnItemClickListener() { 
     @Override 
     public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 
      Intent newActivity = new Intent(getApplicationContext(), BrowseProduct.class); 
      newActivity.putExtra("1st column value", mProductList.get(???)); 
      newActivity.putExtra("2nd column value", mProductList.get(???)); 
      newActivity.putExtra("3rd column value", mProductList.get(???)); 
      newActivity.putExtra("4th column value", mProductList.get(???)); 
      startActivity(newActivity); 
     } 
    }); 
} 

}

Answer 1

您需要首先獲得位置引用，然後獲取的該值來自ArrayList的位置

mProductList.get(position).getProductName(); 

快樂編碼！

Answer 2

您應該聲明在Product類獲取和設置方法

nowyEkran.putExtra("1st column value", mProductList.get(position).getProduct()); 

例

 /** 
     * Created by Intellij Amiyo on 03-04-2017. 
     */ 

     public class Product implements Serializable { 

     public String product,price,description; 
     int id; 

     // Empty constructor 
     public Product() 
     { 

     } 

     // constructor 
     public Product(int id,String product,String price,String description) { 

      this.price = price; 
      this.product = product; 
      this.description = description; 
      this.id=id; 

     } 

      public String getprice() { 
      return this.price; 
     } 

     public void setprice(String price) { 
      this.price = price; 
     } 
     public String getProduct() { 
      return this.product; 
     } 

     public void setProduct(String product) { 
      this.product = product; 
     } 
     public String getDescription() { 
      return this.description; 
     } 

     public void setDescription(String product) { 
      this.description = description; 
     } 

     public int getID() { 
      return this.id; 
     } 

     public void setID(int id) { 
      this.id = id; 
     } 

} 

Answer 3

試試這個

mProductList.get(position).getMethod() 

Answer 4

這將讓索引你的數組列表0 1 2，它會返回對象

mProductList.get(0); 
mProductList.get(1); 
mProductList.get(2); 

Answer 5

把你的大括號（）中的位置。像下面...

lvProduct.setOnItemClickListener(new AdapterView.OnItemClickListener() { 
     @Override 
     public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 
      Intent newActivity = new Intent(getApplicationContext(), BrowseProduct.class); 
      newActivity.putExtra("1st column value", mProductList.get(position)); 
      newActivity.putExtra("2nd column value", mProductList.get(position)); 
      newActivity.putExtra("3rd column value", mProductList.get(position)); 
      newActivity.putExtra("4th column value", mProductList.get(position)); 
      startActivity(newActivity); 
     } 
    }); 

希望這將幫助你...（：

Answer 6

mProductList.get(position).price 

Answer 7

@Override 
     public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 

     } 

您可以從回調方法的int position參數獲得點擊的項目位置

Answer 8

你已經有了一個叫做position的參數，這個參數是get的參數，但是那個將會是return a Product object和y你需要從那裏閱讀給定的成員。既然你不同意的Productclass與我們的代碼，我們只能猜測：

@Override 
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 
     Intent newActivity = new Intent(getApplicationContext(), BrowseProduct.class); 
     newActivity.putExtra("1st column value", mProductList.get(position).ID); 
     newActivity.putExtra("2nd column value", mProductList.get(position).Name); 
     newActivity.putExtra("3rd column value", mProductList.get(position).Price); 
     newActivity.putExtra("4th column value", mProductList.get(position).Description); 
     startActivity(newActivity); 
    }