需要来自xml属性自定义小部件的图像ID

Question

我有一个自定义控件(现在很简单)就像一个按钮.它需要显示未按下和按下的图像.它在活动中出现多次,并且具有不同的图像对,具体取决于它的使用位置.想想工具栏图标 - 与此类似.

这是我的布局的摘录:

<TableLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:MyApp="http://schemas.android.com/apk/res/com.example.mockup"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent" >

  <TableRow>
    <com.example.mockup.ImageGestureButton
      android:id="@+id/parent_arrow"
      android:src="@drawable/parent_arrow"
      MyApp:srcPressed="@drawable/parent_arrow_pressed"
      ... />
     ...
  </TableRow>
</TableLayout>

attrs.xml:

<?xml version="1.0" encoding="utf-8"?> 
<resources> 
    <declare-styleable name="ImageGestureButton"> 
        <attr name="srcPressed" format="reference" /> 
    </declare-styleable> 
</resources> 

并且,在R.java中,人们发现:

public static final class drawable {
    public static final int parent_arrow=0x7f020003;
    public static final int parent_arrow_pressed=0x7f020004;
    ...
}

在窗口小部件实例化期间,我想确定活动xml中声明的id.我怎么做？我试过这个(我使用工作代码更新了我原来的帖子;所以,以下工作.)

public class ImageGestureButton extends ImageView
   implements View.OnTouchListener
{
  private Drawable unpressedImage;
  private Drawable pressedImage;

  public ImageGestureButton (Context context, AttributeSet attrs)
  {
    super(context, attrs);
    setOnTouchListener (this);

    unpressedImage = getDrawable();

    TypedArray a = context.obtainStyledAttributes (attrs, R.styleable.ImageGestureButton, 0, 0);
    pressedImage = a.getDrawable (R.styleable.ImageGestureButton_srcPressed);
  }

  public boolean onTouch (View v, MotionEvent e)
  {
    if (e.getAction() == MotionEvent.ACTION_DOWN)
    {
      setImageDrawable (pressedImage);
    }
    else if (e.getAction() == MotionEvent.ACTION_UP)
    {
      setImageDrawable (unpressedImage);
    }

    return false;
  }
}

Answer 1

如果你想获得drawable,请使用TypedArray.getDrawable().在您的示例中,您使用的是getString().

在你的declare-styleable使用中

   <attr name="srcPressed" format="reference" />