錯誤：這個類應該提供一個默認構造函數（一個沒有參數的公共構造函數）

Question

喲。嘗試生成已簽名的apk時出現此錯誤。怎麼回事 該類應該提供一個默認的構造函數（公共構造函數沒有參數） 我該如何解決這個問題？ 包com.deejaykingsteve.kingsblastfighter

import android.content.Context; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.graphics.Rect; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 

public class king { 
private Bitmap bitmap; 
private int x; 
private int y; 
private int speed = 0; 
private boolean boosting; 
private final int GRAVITY = -10; 
private int maxY; 
private int minY; 
private final int MIN_SPEED = 1; 
private final int MAX_SPEED = 20; 
private Rect detectCollision; 
public king(Context context, int screenX, int screenY) { 
    x = 75; 
    y = 50; 
    speed = 1; 
    bitmap = 
BitmapFactory.decodeResource(context.getResources(), 
R.drawable.king); 
    maxY = screenY - bitmap.getHeight(); 
    minY = 0; 
    boosting = false; 
    detectCollision = new Rect(x, y, bitmap.getWidth(), 
bitmap.getHeight()); 
} 
public void setBoosting() { 
    boosting = true; 
} 
public void stopBoosting() { 
    boosting = false; 
} 
public void update(){ 
    if (boosting) { 
     speed += 3; 
    } else { 
     speed -= 4; 
    } 
    if (speed > MAX_SPEED) { 
     speed = MAX_SPEED; 
    } 
    if (speed < MIN_SPEED) { 
     speed = MIN_SPEED; 
    } 
    y -= speed + GRAVITY; 
    if (y < minY) { 
     y = minY; 
    } 
    if (y > maxY) { 
     y = maxY; 
    } 
    detectCollision.left = x; 
    detectCollision.top = y; 
    detectCollision.right = x + bitmap.getWidth(); 
    detectCollision.bottom = y + bitmap.getHeight(); 

    } 
    public Rect getDetectCollision() { 
    return detectCollision; 
    } 


public Bitmap getBitmap() { 
    return bitmap; 
} 

public int getX() { 
    return x; 
} 

public int getY() { 
    return y; 
} 

public int getSpeed() { 
    return speed; 
} 
} 

Answer 1

以最小的研究，這樣的事情，因爲這不會有事要問這裏！

例子：

public class StackOverflow{ 

public StackOverflow(){ // here you have the public constructor with no argument 

} 

}