按钮单击效果（悬停）未在Android中的UI上显示

Question

因为我需要圆形按钮，所以我使用以下代码

这是我在layout.xml文件中的按钮

<RoundedImageView
        android:id="@+id/btnCheck"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:src="@drawable/ic_launcher" />

为此，我使用下面的类：

public class RoundedImageView extends ImageView {

   public RoundedImageView(Context ctx, AttributeSet attrs) {
          super(ctx, attrs);
   }

   @Override
   protected void onDraw(Canvas canvas) {

          Drawable drawable = getDrawable();

          if (drawable == null) {
                 return;
          }

          if (getWidth() == 0 || getHeight() == 0) {
                 return;
          }
          Bitmap b = ((BitmapDrawable) drawable).getBitmap();
          Bitmap bitmap = b.copy(Bitmap.Config.ARGB_8888, true);

          int w = getWidth(), h = getHeight();

          Bitmap roundBitmap = getRoundedCroppedBitmap(bitmap, w);
          canvas.drawBitmap(roundBitmap, 0, 0, null);

   }

   public static Bitmap getRoundedCroppedBitmap(Bitmap bitmap, int radius) {
          Bitmap finalBitmap;
          if (bitmap.getWidth() != radius || bitmap.getHeight() != radius)
                 finalBitmap = Bitmap.createScaledBitmap(bitmap, radius, radius,
                              false);
          else
                 finalBitmap = bitmap;
          Bitmap output = Bitmap.createBitmap(finalBitmap.getWidth(),
                       finalBitmap.getHeight(), Config.ARGB_8888);
          Canvas canvas = new Canvas(output);

          final Paint paint = new Paint();
          final Rect rect = new Rect(0, 0, finalBitmap.getWidth(),
                       finalBitmap.getHeight());

          paint.setAntiAlias(true);
          paint.setFilterBitmap(true);
          paint.setDither(true);
          canvas.drawARGB(0, 0, 0, 0);
          paint.setColor(Color.parseColor("#BAB399"));
          canvas.drawCircle(finalBitmap.getWidth() / 2 + 0.7f,
                       finalBitmap.getHeight() / 2 + 0.7f,
                       finalBitmap.getWidth() / 2 + 0.1f, paint);
          paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
          canvas.drawBitmap(finalBitmap, rect, rect, paint);

          return output;
   }
}

在我的MainActivity类中，我声明了ImageView：

private ImageView imageBtnCheck;

在OnCreate中，我有以下代码，“ check_icon”是drawable-hdpi文件夹中的.png文件。

imageBtnCheck = (ImageView) findViewById(R.id.btnCheck);
Bitmap iconCheck = BitmapFactory.decodeResource(getResources(),R.drawable.check_icon);          
imageBtnCheck.setImageBitmap(iconCheck);

Onclick代码如下，我在onCreate（）中调用wireEventForBtnCheck：-

private void wireEventForBtnCheck() {
    imageBtnCheck.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View view) {
        //Code here
        }
    });
}

通过此代码，我能够根据需要显示带有图标的圆形按钮。 而且，当我单击按钮时，单击事件也在起作用。 但是用户界面中的点击效果（悬停）并未发生，因为它发生在普通的android按钮上。

是否添加了任何属性（或）任何种类的代码，以显示动态加载按钮的点击效果？

Answer 1

设置可绘制图像按钮时，悬停效果不佳。 因此您必须对图像按钮使用选择器。 例如在可绘制文件夹中创建选择器文件

ImageButtonSelector.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_pressed="true" 
      android:drawable="@drawable/selected"/> <!-- pressed state -->
<item android:state_focused="true" 
      android:drawable="@drawable/focused"/> <!-- focused state -->
<item android:drawable="@drawable/default"/> <!-- default state -->

</selector>

然后将此选择器设置为图像按钮源

<RoundedImageView
    android:id="@+id/btnCheck"
    android:layout_width="50dp"
    android:layout_height="50dp"
    android:src="@drawable/ImageButtonSelector" />

Answer 2

您可以通过可绘制的xml来实现此目的.ic_launcher.xml

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_focused="true" android:state_pressed="true" android:drawable="@drawable/ic_launcher_pressed"/>
    <item android:state_focused="false" android:state_pressed="true" android:drawable="@drawable/ic_launcher_pressed"/>
    <item android:state_focused="true" android:drawable="@drawable/ic_launcher_selected"/>
    <item android:state_focused="false" android:state_pressed="false" android:drawable="@drawable/ic_launcher_default"/>
</selector> 

或者您可以通过Java文件进行设置

StateListDrawable stateListDrawable = new StateListDrawable();
stateListDrawable .addState(new int[] {android.R.attr.state_pressed},
    getResources().getDrawable(R.drawable.ic_launcher_pressed));
stateListDrawable .addState(new int[] {android.R.attr.state_focused},
    getResources().getDrawable(R.drawable.ic_launcher_selected));
stateListDrawable .addState(new int[] {},
    getResources().getDrawable(R.drawable.ic_launcher_default));
imageBtnCheck.setImageDrawable(stateListDrawable);