Question

我的自定义Drawable是这样的：

public class SeekBarBackgroundDrawable extends Drawable {
    Paint mBasePaint = null;

    public SeekBarBackgroundDrawable() {
        super();

        mBasePaint = new Paint();
        mBasePaint.setAntiAlias(true);
        mBasePaint.setStyle(Paint.Style.STROKE);
        mBasePaint.setStrokeCap(Paint.Cap.ROUND);
        mBasePaint.setStrokeWidth(10);
        mBasePaint.setColor(0xFF00FF00);

    }

    @Override
    public void draw(Canvas canvas) {    
        Rect r = getBounds();
        canvas.drawLine(r.left, canvas.getHeight()/2,r.right,canvas.getHeight()/2, mBasePaint);
    }

现在，这个drawable用于layer-list参数color和width，如下所示：

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:id="@android:id/background">
        <cdev.mypreferences.SeekBarBackgroundDrawable
        android:width="1dp" android:color="@color/bg_color">

        </cdev.mypreferences.SeekBarBackgroundDrawable>
    </item>
    <item android:id="@android:id/progress">
        <clip>
            <shape android:shape="rectangle">
                <corners android:radius="20dp"></corners>
                <solid android:color="@color/seekbar_progress"></solid>
            </shape>
        </clip>
    </item>

</layer-list>

如何从xml到Drawable课程中获取参数？我需要设置mBasePaint笔画宽度和颜色？

Answer 1

Declaring custom drawables in xml可以从API 24开始实现，但我无法使用文档中提到的第一种方法成功实现这一点。

然而，由于问题与其他方面有关，我将尝试回答这一部分。

在自定义Drawable类中添加此项将返回您感兴趣的值：


  private final int[] attrsArray = new int[] {
      android.R.attr.width,
      android.R.attr.color,
  };

  @Override public void inflate(@NonNull Resources r, @NonNull XmlPullParser parser,
      @NonNull AttributeSet attrs) throws XmlPullParserException, IOException {
    super.inflate(r, parser, attrs);

    final TypedArray a = r.obtainAttributes(attrs, attrsArray);
    float width = a.getDimensionPixelSize(0, 0);
    @SuppressLint("ResourceType")
    int color = a.getColor(1, 0);

    a.recycle();
  }

从xml获取自定义可绘制参数

1 个答案: