Question

我在扩展View类时遇到问题，XML正常运行，因为我已经尝试使用ImageView，但不能使用我的自定义类...

BubbleView.java

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Canvas;
import android.graphics.drawable.LayerDrawable;
import android.view.View;

public class BubbleView extends View {

    LayerDrawable rootBubble;

    public BubbleView(Context context) {           
            super(context);

            Resources res = this.getResources();
            rootBubble = (LayerDrawable) res.getDrawable(R.drawable.bubble);

    }

    @Override
    protected void onDraw(Canvas canvas) {
            super.onDraw(canvas);
            rootBubble.draw(canvas);

    }


}

bubble.xml（在res / drawable-mdpi文件夹中）

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item>
  <shape
   android:shape="rectangle">
        <solid android:color="#FFFF0000" />
        <size android:width="100px" android:height="100px" />
        <padding android:bottom="1dp"/>
    </shape>
</item>

<item>
  <shape
   android:shape="oval">
        <solid android:color="#FFFFFFFF" />
        <size android:width="100px" android:height="100px" />
    </shape>
</item>

</layer-list>

主要活动

public class VisualManagerActivity extends Activity {


  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);

     LinearLayout main = new LinearLayout(this);      
     main.addView(new BubbleView(this));      
     setContentView(main);
  }
}

谢谢！

Answer 1

LayerDrawable是Drawable的子类，因此您仍需要将drawable分配给View。

我建议BubbleView为您的自定义类扩展ImageView而不是View。通过这种方式，您可以在主要活动中以任何布局重复使用drawable。

public class BubbleView extends ImageView {

    public BubbleView(Context context) {           
        super(context);
        init( context );
    }

    public BubbleView(Context context, AttributeSet attrs) {           
        super(context, attrs);
        init( context );
    }        

    public BubbleView(Context context, AttributeSet attrs, int defStyle) {           
        super(context, attrs, defStyle);
        init( context );
    }

    private void init(Context context){
        Resources res = this.getResources();
        setImageDrawable(res.getDrawable(R.drawable.bubble));

        /* Any other initialization */

    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        /* Any other drawing functionality */

    }
}

有帮助吗？

Answer 2

protected void onDraw(Canvas canvas)
{
    super.onDraw(canvas);

    paint = new Paint();

    paint.setColor(Color.WHITE);


    Rect bounds = new Rect();
    paint.getTextBounds(name, 0, name.length(), bounds);

    LayerDrawable layerDrawable = (LayerDrawable) resources.getDrawable(R.drawable.your_drawble);
    Bitmap b = Bitmap.createBitmap(getWidth(), getHeight(), Bitmap.Config.ARGB_8888);
    layerDrawable.setBounds(0, 0, getWidth(), getHeight());
    layerDrawable.draw(new Canvas(b));

    canvas.drawBitmap(b,0,0,paint);}

自定义视图使用LayerDrawable不显示任何内容的问题

2 个答案: