2016-11-04 147 views
0

我試圖製作一個按鈕,點擊它時會從一組卡中選取一張隨機卡並將其顯示到ImageView中。 要做到這一點,我有一個卡類他們的價值和他們的ID(圖像卡名稱繪製)。setImageResource導致應用程序崩潰

public class Carte { 

int valeur; 
static String nomCarte; 

public Carte(int valeur, String nomImage) { 

    valeur = this.valeur; 
    nomCarte = this.nomCarte; 
} 

public static String getImageId() { 
    return nomCarte; 
} 
} 

我對它們進行初始化的52到製表[],當按鈕平局點擊它挑選從標籤[]一個隨機的,我嘗試再改變我的ImageView與採摘卡的圖像獲取卡的ID和使用setImageResource,但它使我的應用程序崩潰,你可以幫我嗎?

這裏是我的mainActivity代碼:

public class MainActivity extends AppCompatActivity { 

protected Carte tab[]; 
protected ImageView imageCarte; 
protected Button afficherCarte; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 

    imageCarte = (ImageView) findViewById(R.id.imageCarte); 

    tab = new Carte[]{new Carte(1, "c_1"), new Carte(1, "d_1"), new Carte(1, "h_1"), new Carte(1, "s_1"), 
        new Carte(2, "c_2"), new Carte(2, "d_2"), new Carte(2, "h_2"), new Carte(2, "s_2"), 
        new Carte(3, "c_2"), new Carte(3, "d_3"), new Carte(3, "h_3"), new Carte(3, "s_3"), 
        new Carte(4, "c_4"), new Carte(4, "d_4"), new Carte(4, "h_4"), new Carte(4, "s_4"), 
        new Carte(5, "c_5"), new Carte(5, "d_5"), new Carte(5, "h_5"), new Carte(5, "s_5"), 
        new Carte(6, "c_6"), new Carte(6, "d_6"), new Carte(6, "h_6"), new Carte(6, "s_6"), 
        new Carte(7, "c_7"), new Carte(7, "d_7"), new Carte(7, "h_7"), new Carte(7, "s_7"), 
        new Carte(8, "c_8"), new Carte(8, "d_8"), new Carte(8, "h_8"), new Carte(8, "s_8"), 
        new Carte(9, "c_9"), new Carte(9, "d_9"), new Carte(9, "h_9"), new Carte(9, "s_9"), 
        new Carte(10, "c_10"), new Carte(10, "d_10"), new Carte(10, "h_10"), new Carte(10, "s_10"), 
        new Carte(11, "c_11"), new Carte(11, "d_11"), new Carte(11, "h_11"), new Carte(11, "s_11"), 
        new Carte(12, "c_12"), new Carte(12, "d_12"), new Carte(12, "h_12"), new Carte(12, "s_12"), 
        new Carte(13, "c_13"), new Carte(13, "d_13"), new Carte(13, "h_13"), new Carte(13, "s_13"),}; 


    afficherCarte = (Button) findViewById(R.id.afficherCarte); 
    afficherCarte.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      Random r = new Random(); 
      int i1 = r.nextInt(53 - 1) + 1; 
      int id = getResources().getIdentifier(tab[i1].getImageId(), "drawable", getPackageName()); 
      imageCarte.setImageResource(id); 
     } 
    }); 

} 

} 

回答

0

你的構造函數是錯誤的,你做你的圖像標識靜態字段,這將永遠是相同的ID,如果你不將其刪除。

public Carte(int valeur, String nomImage) { 
    valeur = this.valeur; 
    nomCarte = this.nomCarte; 
} 

您永遠不會將方法參數存儲到類字段中。 你必須圍繞使用它像

this.valeur = valeur; 
this.nomCarte = nomCarte; 

其他方式和你的getter不會返回null因爲這一點。除此之外,刪除靜態修改器

public String getImageId() { 
    return nomCarte; 
} 
+0

這工作完美,我編輯此文件試圖正確使用setImageResource和完成忘記了我爲靜態編輯。對於構造函數來說,這是我的一個基本錯誤,我的錯誤。非常感謝 ! – Rhohen

+0

@Rhohen沒問題。不要忘記接受答案。 –