Question

我在我的按钮类中覆盖了onDraw。

我如何知道onDraw里面按下了按钮？

Answer 1

在按钮的onDraw(..)方法中，您只需检查this.isPressed()
按下按钮时，这应返回true。

编辑：
您还可以在Button's subclass：

中实施触摸事件

Example:

public class tempButton extends Button {

public tempButton(Context context) {
    super(context);
    // TODO Auto-generated constructor stub
}

@Override
public boolean onTouchEvent(MotionEvent event) {
    // TODO Auto-generated method stub
     switch(event.getAction())
     {
        case MotionEvent.ACTION_DOWN:

            //Button Pressed, Change the color of your Button here.

        break;

        case MotionEvent.ACTION_UP:

        break;

        case MotionEvent.ACTION_MOVE:

        break;

     }

    return true;
}

}

我希望这会有所帮助。

Answer 2

尝试这个自定义Drawable：

class SLD extends StateListDrawable {
    @Override
    protected boolean onStateChange(int[] stateSet) {
        invalidateSelf();
        return super.onStateChange(stateSet);
    }

    @Override
    public void draw(Canvas canvas) {
        int[] states = getState();
        Log.d(TAG, "draw " + StateSet.dump(states));
        boolean pressed = false;
        boolean focused = false;
        for (int i = 0; i < states.length; i++) {
            int state = states[i];
            if (state == android.R.attr.state_pressed) {
                pressed = true;
            }
            if (state == android.R.attr.state_focused) {
                focused = true;
            }
        }
        if (pressed) {
            canvas.drawColor(0xffff8800);
        } else
        if (focused) {
            canvas.drawColor(0xffff0000);
        } else
        canvas.drawColor(0xffaaaaaa);
    }
}

并在onCreate中使用以下内容进行测试：

LinearLayout ll = new LinearLayout(this);
ll.setOrientation(LinearLayout.VERTICAL);
for (int i = 0; i < 5; i++) {
    Button b = new Button(this);
    b.setText("button #" + i);
    b.setBackgroundDrawable(new SLD());
    ll.addView(b);
}
setContentView(ll);

如何知道MyButton :: OnDraw中的状态被压缩（聚焦）

2 个答案: