java - 为什么 setAlpha() 作用于我的所有按钮，而 setImageResource() 只作用于一个按钮？

Question

目前我的按钮不起作用。前两次按下任何按钮时，所有按钮都会受到影响，而不仅仅是已按下的按钮。

交换:

seatButton[i].setAlpha(255);

对于:

seatButton[i].setImageResource(0x7f020007)

我的代码有效!只有我按下的按钮才会生效。为什么？

@Override
public void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    table = new Table(); //Creates Table
    seatButton = new ImageButton[10]; //Creates Array of buttons
    seatStats = new TextView[10]; //Creates array for stat panels


    //Creates longClickListener, used for players to sit in or out.
    longClickListener = new View.OnLongClickListener() 


    {


        @Override
        public boolean onLongClick(View v) 
        {
            for(int i=0; i<10; i++)
            {
                //Each seat[i] will correspond with each imageButtoni+1
                if(v.getId() == (getResources().getIdentifier("imageButton" + (i+1), "id", "en.deco.android.livehud"))) 
                {
                    //If the seat is empty fill it, place a player in the seat and change the button from translucent to opaque
                    if(table.seats[i].getState().equals("empty"))
                    {

                        seatButton[i].setAlpha(255);
                        //seatButton[i].setImageResource(0x7f020000);
                        table.seats[i].sit(new Player());
                        seatStats[i].setVisibility(View.VISIBLE);
                        Toast.makeText(GUI.this, table.seats[i].getState(), Toast.LENGTH_SHORT).show();
                    }
                    //If the seat is full, empty it
                    else
                    {
                        seatButton[i].setAlpha(80);
                        //seatButton[i].setImageResource(0x7f020007);
                        table.seats[i].sitOut();
                        seatStats[i].setVisibility(View.INVISIBLE);
                        Toast.makeText(GUI.this, table.seats[i].getState() + i, Toast.LENGTH_SHORT).show();
                    }
                }
            }
            return true;
        }
    };


    //Assigns the buttons and stats panels defined in the layout xml to their appropiate java arrays. Also sets clickListeners to buttons.
    for(int i = 0; i < 10; i++)
    {
        seatButton[i] = (ImageButton) findViewById(getResources().getIdentifier("imageButton" + (i+1), "id", "en.deco.android.livehud"));
        seatStats[i] = (TextView) findViewById(getResources().getIdentifier("textView" + (i+1), "id", "en.deco.android.livehud"));
        seatButton[i].setOnLongClickListener(longClickListener);
        seatButton[i].setAlpha(80);
    }

Answer 1

您正在与 == 进行字符串比较，这意味着您正在比较引用而不是值。这可能不是您想要的，因此您应该将其更改为:

if(table.seats[i].getState() == "empty") { ... }

至:

if(table.seats[i].getState().equals("empty")) { ... }

除此之外，根据setAlpha(float alpha)(API 11方法，仅供引用)的文档，传递的float应该在[0... 1]。

您要设置的图像资源是 ImageManager 的 R.id.transparent_background。这可能表明您的逻辑有效，但错误确实出在设置 alpha 值的某个地方。