java - 如何防止方法被调用两次？

Question

我想以编程方式检查函数是否被调用。如果之前调用过，则不允许并忽略第二次调用，如果没有则让按钮调用。为什么我需要这样做是因为我有一个 longClick 按钮来运行某些功能，如果用户忘记这样做，那么用户将单击另一个按钮，我将放置相同的功能。我需要防止两次运行相同的功能。

public class ActivityA extends Activity{

private static boolean isScreenShotTaken = false;

blankcard.setOnLongClickListener(new OnLongClickListener() {

       if(!isScreenShotTaken)
            {
                Bitmap bitmap = takeScreenshot();
                saveBitmap(bitmap);
                isScreenShotTaken = true;

            }

        return false;
        }
});



btnsend.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub

Intent intent = new Intent(Templates.this, MailCard.class);
intent.putExtra("name", Name);

if(!isScreenShotTaken)
            {
                Bitmap bitmap = takeScreenshot();
                saveBitmap(bitmap);
                isScreenShotTaken = true;
            }

startActivity(intent);             

        }
    });


public Bitmap takeScreenshot() {

// code exist here
//if called once, second call ignore

}

public void saveBitmap(Bitmap bitmap) {

// code exist here
//if called once, second call ignore

  }
}

感谢您的建议。

Answer 1

我的版本:

我会这样写:

// In the declaration section of your class.
private static boolean isScreenShotTaken = false;

// In the code.
btnsend.setOnClickListener
(
    new View.OnClickListener()
    {
        @Override
        public void onClick(View v)
        {
            if(!isScreenShotTaken)
            {
                Bitmap bitmap = takeScreenshot();
                saveBitmap(bitmap);
                isScreenShotTaken = true;
            }
        }
    }
);

blankcard.setOnLongClickListener
(
    new OnLongClickListener()
    {
        @Override
        public boolean onLongClick(View arg0)
        {
            if(!isScreenShotTaken)
            {
                Bitmap bitmap = takeScreenshot();
                saveBitmap(bitmap);
                isScreenShotTaken = true;
            }
        }
    }
);