我有一个自定义控件(目前非常简单),类似于按钮。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,取决于它在哪里使用。想象一下工具栏图标-类似于那个。
这是我的布局摘录:
<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>
在R.java中,可以找到以下内容:
public static final class drawable {
public static final int parent_arrow=0x7f020003;
public static final int parent_arrow_pressed=0x7f020004;
...
}
在小部件实例化期间,我想确定在活动XML中声明的ID。 我该怎么做? 我尝试了这个(我使用工作代码更新了原始帖子; 因此,以下内容有效。)
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;
}
}