如何在Android的按钮中设置矢量图的大小？

Question

Android Studio 的矢量图工具可以将矢量图转换为 PNG 格式，以适配 Lollipop 以下的设备。但是，我得到的 PNG 图片质量非常差，就像你在这里看到的一样：。

更重要的是，按钮的背景色应该是左边你所看到的浅绿色，但是矢量图却覆盖了它。

<item android:state_checked="true"
    android:drawable="@drawable/show">
    <shape android:shape="rectangle">
        <corners android:bottomRightRadius="8dp"/>
        <solid android:color="@color/waveComponentGreen"/>
    </shape>
</item>

<item android:state_checked="false"
    android:drawable="@drawable/hide">
    <shape android:shape="rectangle">
        <corners android:bottomRightRadius="8dp"/>
        <solid android:color="@color/waveComponentGreen"/>
    </shape>
</item>

可绘制对象的XML代码如下（默认来自Material Icons）：

<vector xmlns:android="http://schemas.android.com/apk/res/android"
    android:width="24dp"
    android:height="24dp"
    android:viewportWidth="24.0"
    android:viewportHeight="24.0">
<path
    android:fillColor="#FF000000"
    android:pathData="M8.59,16.34l4.58,-4.59 -4.58,-4.59L10,5.75l6,6 -6,6z"/>

我希望通过调整数值使图标显示得更小，但我发现增加视口尺寸会使图标变小，但我不确定为什么。

所以问题是: 如何让图标和生成的PNG图片显示得更小、更清晰，并且设置资源文件中的背景颜色？谢谢。

编辑: 我通过在一个单独的xml文件中使用层列表来将纯色背景与图标结合起来：

<layer-list
xmlns:android="http://schemas.android.com/apk/res/android" >
<item>
    <shape android:shape="rectangle">
        <corners android:bottomRightRadius="10dp"/>
        <solid android:color="@color/waveComponentGreen"/>
    </shape>
</item>
<item android:drawable="@drawable/show"
    android:top="10dp"
    android:bottom="10dp"
    android:left="10dp"
    android:right="10dp"
    />

结果如下：

结果是：

通过增加矢量可绘制对象的宽度和高度，我成功地减少了模糊。但是，如果没有android:top|bottom|left|right标签，可绘制对象会被拉伸到整个按钮区域。第二个按钮不需要有背景纯色，因此我没有使用层列表标签=>无法为可绘制对象设置top|bottom|left|right边距。
如果我减小按钮大小，就是减小按钮的可点击区域。

我的更新问题是如何在按钮/切换按钮/单选按钮内设置矢量可绘制对象的大小，而不会减小按钮本身的大小？

更新
我找不到在API 21之前的设备上调整矢量可绘制对象大小的方法。因此，我将按钮本身变小，并增加了每个按钮的触摸区域。

- Valkova.V

---

视口是绘制图标的空间，pathData则为各种坐标指令，指导形状如何绘制。例如，如果您有一个 24x24 的视口，并且从点 0,12 到点 24,12 绘制了一条直线，那么这就是一条水平线，位于您的视口中央，从一侧延伸到另一侧。如果将视口大小更改为 48x48，但您的线仍然是从点 0,12 到点 24,12，则它就不再从中间开始，并且无法覆盖整个视口。 - Lewis McGeary

Answer 1

任何可缩放图形的正确方法是使用vectorDrawable.setBounds(left,top,right,bottom), 但不幸的是，对于矢量图而言这并不起作用（为什么Google？）。

所以我想到了一个解决办法：加载矢量图，将其转换为位图图形，然后就可以在位图图形上使用setBounds方法了。请注意，这里是在缩放位图图像，因此可能会失去一些图像的清晰度。我主要使用这些方法时需要将可绘制对象用作文本视图或按钮的复合可绘制对象。

最终，我编写了一个帮助类，它将加载矢量图并返回一个可实际缩放和着色的位图可绘制对象。我已经在API19到23的级别上进行了测试，它能正常工作。

不要忘记在build.gradle中使用vectorDrawables.useSupportLibrary = true。

public class VectorDrawableUtils {

/**
 * Gets a Bitmap from provided Vector Drawable image
 *
 * @param vd VectorDrawable
 * @return Bitmap
 */
public static Optional<Bitmap> createBitmapFromVectorDrawable(final @NonNull Drawable vd) {
    try {
        Bitmap bitmap;
        bitmap = Bitmap.createBitmap(vd.getIntrinsicWidth(), vd.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(bitmap);
        vd.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
        vd.draw(canvas);
        return Optional.of(bitmap);
    } catch (OutOfMemoryError e) {
        Injector.getDependency(getContext(), IEventTracker.class).logHandledException(e);
        return Optional.empty();
    }
}

/**
 * Loads vector drawable and apply tint color on it.
 */
public static Drawable loadVectorDrawableWithTintColor(final @DrawableRes int vdRes,
                                                       final @ColorRes int clrRes,final Context context) {
    Drawable drawable = ContextCompat.getDrawable(context, vdRes);
    DrawableCompat.setTint(drawable, getContext().getResources().getColor(clrRes));
    return drawable;
}

/**
 * Converts given vector drawable to Bitmap drawable
 */
public static BitmapDrawable convertVectorDrawableToBitmapDrawable(final @NonNull Drawable vd) {
    //it is safe to create empty bitmap drawable from null source
    return new BitmapDrawable(createBitmapFromVectorDrawable(vd).get());
}

/**
 * Loads vector drawable , aplys tint on it and returns a wrapped bitmap drawable.
 * Bitmap drawable can be resized using setBounds method (unlike the VectorDrawable)
 * @param context Requires view context !
 */
public static Drawable loadVectorDrawableWithTint(
        final @DrawableRes int vectorDrawableRes, final @ColorRes int colorRes,final Context context) {
    Drawable vd = VectorDrawableUtils.loadVectorDrawableWithTintColor(vectorDrawableRes,
            colorRes, context);
    final BitmapDrawable bitmapDrawable = VectorDrawableUtils.convertVectorDrawableToBitmapDrawable(vd);
    ColorStateList tint = ContextCompat.getColorStateList(context,colorRes);
    final Drawable wrappedDrawable = DrawableCompat.wrap(bitmapDrawable);
    DrawableCompat.setTintList(wrappedDrawable,tint);
    return wrappedDrawable;
    }
}

现在我会像这样使用这个帮助类：

    Drawable bd = VectorDrawableUtils.loadVectorDrawableWithTint(
                R.drawable.ic_dropdown, R.color.black,getContext());
        bd.setBounds(0, 0, textView.getMeasuredHeight(), textView.getMeasuredHeight());
        textView.setCompoundDrawablesWithIntrinsicBounds(null, null, bd, null);

使用View或Activity的Context而不是Application Context非常重要！希望这可以解决你的问题，或者对其他人有所帮助。如果有更好、更清晰的解决方案，我也很感兴趣。

- Ivelius

Answer 2

MyTextView类：

public class MyTextView extends AppCompatTextView {

public MyTextView(Context context) {
    super(context);
}

public MyTextView(Context context, AttributeSet attrs) {
    super(context, attrs);
    initAttrs(context, attrs);
}

public MyTextView(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
    initAttrs(context, attrs);
}

void initAttrs(Context context, AttributeSet attrs) {
    if (attrs != null) {
        TypedArray attributeArray = context.obtainStyledAttributes(
                attrs,
                R.styleable.MyTextView);

        int defaultWidthHeight = 0;
        int widthHeight = 0;
        Drawable drawableLeft = null;
        Drawable drawableStart = null;
        Drawable drawableRight = null;
        Drawable drawableEnd = null;
        Drawable drawableBottom = null;
        Drawable drawableTop = null;

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            drawableLeft = attributeArray.getDrawable(R.styleable.MyTextView_drawableLeftCompatTextView);
            drawableStart = attributeArray.getDrawable(R.styleable.MyTextView_drawableStartCompatTextView);
            drawableRight = attributeArray.getDrawable(R.styleable.MyTextView_drawableRightCompatTextView);
            drawableEnd = attributeArray.getDrawable(R.styleable.MyTextView_drawableEndCompatTextView);
            drawableBottom = attributeArray.getDrawable(R.styleable.MyTextView_drawableBottomCompatTextView);
            drawableTop = attributeArray.getDrawable(R.styleable.MyTextView_drawableTopCompatTextView);
        } else {
            final int drawableLeftId = attributeArray.getResourceId(R.styleable.MyTextView_drawableLeftCompatTextView, -1);
            final int drawableStartId = attributeArray.getResourceId(R.styleable.MyTextView_drawableStartCompatTextView, -1);
            final int drawableRightId = attributeArray.getResourceId(R.styleable.MyTextView_drawableRightCompatTextView, -1);
            final int drawableEndId = attributeArray.getResourceId(R.styleable.MyTextView_drawableEndCompatTextView, -1);
            final int drawableBottomId = attributeArray.getResourceId(R.styleable.MyTextView_drawableBottomCompatTextView, -1);
            final int drawableTopId = attributeArray.getResourceId(R.styleable.MyTextView_drawableTopCompatTextView, -1);

            if (drawableLeftId != -1)
                drawableLeft = AppCompatResources.getDrawable(context, drawableLeftId);
            if(drawableStartId != -1)
                drawableStart = AppCompatResources.getDrawable(context, drawableStartId);
            if (drawableRightId != -1)
                drawableRight = AppCompatResources.getDrawable(context, drawableRightId);
            if(drawableEndId != -1)
                drawableEnd = AppCompatResources.getDrawable(context, drawableEndId);
            if (drawableBottomId != -1)
                drawableBottom = AppCompatResources.getDrawable(context, drawableBottomId);
            if (drawableTopId != -1)
                drawableTop = AppCompatResources.getDrawable(context, drawableTopId);
        }

        if(!attributeArray.hasValue(R.styleable.MyTextView_drawableWidthHeightCompatTextView)) {
            if (attributeArray.hasValue(R.styleable.MyTextView_drawableLeftCompatTextView)) {
                defaultWidthHeight = drawableLeft.getIntrinsicWidth();
            } else if (attributeArray.hasValue(R.styleable.MyTextView_drawableStartCompatTextView)) {
                defaultWidthHeight = drawableStart.getIntrinsicWidth();
            } else if (attributeArray.hasValue(R.styleable.MyTextView_drawableRightCompatTextView)) {
                defaultWidthHeight = drawableRight.getIntrinsicWidth();
            } else if (attributeArray.hasValue(R.styleable.MyTextView_drawableEndCompatTextView)) {
                defaultWidthHeight = drawableEnd.getIntrinsicWidth();
            } else if (attributeArray.hasValue(R.styleable.MyTextView_drawableBottomCompatTextView)) {
                defaultWidthHeight = drawableBottom.getIntrinsicWidth();
            } else if (attributeArray.hasValue(R.styleable.MyTextView_drawableTopCompatTextView)) {
                defaultWidthHeight = drawableTop.getIntrinsicWidth();
            }

            widthHeight = attributeArray.getInt(R.styleable.MyTextView_drawableWidthHeightCompatTextView, defaultWidthHeight);
        } else
            widthHeight = attributeArray.getInt(R.styleable.MyTextView_drawableWidthHeightCompatTextView, defaultWidthHeight);

        if(attributeArray.hasValue(R.styleable.MyTextView_drawableColorCompatTextView)){
            ColorStateList tintColor = attributeArray.getColorStateList(R.styleable.MyTextView_drawableColorCompatTextView);
            if (attributeArray.hasValue(R.styleable.MyTextView_drawableLeftCompatTextView)) {
                //drawableLeft.setColorFilter(new PorterDuffColorFilter(tintColor.getDefaultColor(), PorterDuff.Mode.MULTIPLY));
                DrawableCompat.setTintList(drawableLeft, tintColor);
            } else if (attributeArray.hasValue(R.styleable.MyTextView_drawableStartCompatTextView)) {
                //drawableStart.setColorFilter(new PorterDuffColorFilter(tintColor.getDefaultColor(), PorterDuff.Mode.MULTIPLY));
                DrawableCompat.setTintList(drawableStart, tintColor);
            } else if (attributeArray.hasValue(R.styleable.MyTextView_drawableRightCompatTextView)) {
                //drawableRight.setColorFilter(new PorterDuffColorFilter(tintColor.getDefaultColor(), PorterDuff.Mode.MULTIPLY));
                DrawableCompat.setTintList(drawableRight, tintColor);
            } else if (attributeArray.hasValue(R.styleable.MyTextView_drawableEndCompatTextView)) {
                //drawableEnd.setColorFilter(new PorterDuffColorFilter(tintColor.getDefaultColor(), PorterDuff.Mode.MULTIPLY));
                DrawableCompat.setTintList(drawableEnd, tintColor);
            } else if (attributeArray.hasValue(R.styleable.MyTextView_drawableBottomCompatTextView)) {
                //drawableBottom.setColorFilter(new PorterDuffColorFilter(tintColor.getDefaultColor(), PorterDuff.Mode.MULTIPLY));
                DrawableCompat.setTintList(drawableBottom, tintColor);
            } else if (attributeArray.hasValue(R.styleable.MyTextView_drawableTopCompatTextView)) {
                //drawableTop.setColorFilter(new PorterDuffColorFilter(tintColor.getDefaultColor(), PorterDuff.Mode.MULTIPLY));
                DrawableCompat.setTintList(drawableTop, tintColor);
            }
        }

        WrappedDrawable drawableLeftWrapped = new WrappedDrawable(drawableLeft);
        drawableLeftWrapped.setBounds(0, 0, widthHeight, widthHeight);
        WrappedDrawable drawableStartWrapped = new WrappedDrawable(drawableStart);
        drawableStartWrapped.setBounds(0, 0, widthHeight, widthHeight);
        WrappedDrawable drawableRightWrapped = new WrappedDrawable(drawableRight);
        drawableRightWrapped.setBounds(0, 0, widthHeight, widthHeight);
        WrappedDrawable drawableEndWrapped = new WrappedDrawable(drawableEnd);
        drawableEndWrapped.setBounds(0, 0, widthHeight, widthHeight);
        WrappedDrawable drawableBottomWrapped = new WrappedDrawable(drawableBottom);
        drawableBottomWrapped.setBounds(0, 0, widthHeight, widthHeight);
        WrappedDrawable drawableTopWrapped = new WrappedDrawable(drawableTop);
        drawableTopWrapped.setBounds(0, 0, widthHeight, widthHeight);

        setCompoundDrawablesWithIntrinsicBounds(drawableLeftWrapped, drawableTopWrapped, drawableRightWrapped, drawableBottomWrapped);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1)
            setCompoundDrawablesRelativeWithIntrinsicBounds(drawableStartWrapped, drawableTopWrapped, drawableEndWrapped, drawableBottomWrapped);

        attributeArray.recycle();
    }
}

class WrappedDrawable extends Drawable {

    private final Drawable _drawable;
    protected Drawable getDrawable() {
        return _drawable;
    }

    public WrappedDrawable(Drawable drawable) {
        super();
        _drawable = drawable;
    }

    @Override
    public void setBounds(int left, int top, int right, int bottom) {
        //update bounds to get correctly
        super.setBounds(left, top, right, bottom);
        Drawable drawable = getDrawable();
        if (drawable != null) {
            drawable.setBounds(left, top, right, bottom);
        }
    }

    @Override
    public void setAlpha(int alpha) {
        Drawable drawable = getDrawable();
        if (drawable != null) {
            drawable.setAlpha(alpha);
        }
    }

    @Override
    public void setColorFilter(ColorFilter colorFilter) {
        Drawable drawable = getDrawable();
        if (drawable != null) {
            drawable.setColorFilter(colorFilter);
        }
    }

    @Override
    public int getOpacity() {
        Drawable drawable = getDrawable();
        return drawable != null
                ? drawable.getOpacity()
                : PixelFormat.UNKNOWN;
    }

    @Override
    public void draw(Canvas canvas) {
        Drawable drawable = getDrawable();
        if (drawable != null) {
            drawable.draw(canvas);
        }
    }

    @Override
    public int getIntrinsicWidth() {
        Drawable drawable = getDrawable();
        return drawable != null
                ? drawable.getBounds().width()
                : 0;
    }

    @Override
    public int getIntrinsicHeight() {
        Drawable drawable = getDrawable();
        return drawable != null ?
                drawable.getBounds().height()
                : 0;
    }
}
}

attrs.xml:

<declare-styleable name="MyTextView">
    <attr name="drawableColorCompatTextView" format="reference|color"/>
    <attr name="drawableWidthHeightCompatTextView" format="integer"/>
    <attr name="drawableLeftCompatTextView" format="reference"/>
    <attr name="drawableStartCompatTextView" format="reference"/>
    <attr name="drawableRightCompatTextView" format="reference"/>
    <attr name="drawableEndCompatTextView" format="reference"/>
    <attr name="drawableTopCompatTextView" format="reference"/>
    <attr name="drawableBottomCompatTextView" format="reference"/>
</declare-styleable>

使用方法：

<com.packagename.MyTextView
    android:id="@+id/txtUserName"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    app:drawableLeftCompatTextView="@drawable/ic_username"
    app:drawableStartCompatTextView="@drawable/ic_username"
    app:drawableWidthHeightCompatTextView="48"
    app:drawableColorCompatTextView="@color/blue" />

注意：这里唯一的问题是未修改的向量(drawableWidthHeightCompatTextView没有使用)，该向量的width和height为24，
在设备上大小不相等，与调整大小后的向量(向量的width和height为12和drawableWidthHeightCompatTextView="24")不同。

- Dr.jacky

Answer 3

我使用了一个FrameLayout来将一个ImageButton和一个ImageView组合在一起，并能够调整ImageView的大小：

<FrameLayout
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:layout_width="60dp"
  android:layout_height="60dp"
>
  <ImageButton
    android:layout_width="match_parent"
    android:layout_height="match_parent"
  />
  <ImageView
    android:layout_width="50dp"
    android:layout_height="50dp"
    android:layout_gravity="center"
    app:srcCompat="@drawable/baseline_arrow_right_24"
  />
</FrameLayout>

- mortalis

Answer 4

看看我找到的这个，它适用于矢量图和常规可绘制对象！我认为这是我见过的最简短的解决方案。

思路是创建一个具有固定内在大小的自定义可绘制对象，并将绘图工作传递给原始可绘制对象。

final Drawable d = container.getContext().getDrawable(R.drawable.your_drawable);
    Drawable icon = new ColorDrawable(){
        Drawable iconOrig = d;

        @Override
        public void setBounds(int left, int top, int right, int bottom){
            super.setBounds(left, top, right, bottom);//This is needed so that getBounds on this class would work correctly.
            iconOrig.setBounds(left, top, right, bottom);
        }

        @Override
        public void draw(Canvas canvas){
            iconOrig.draw(canvas);
        }

        @Override
        public int getIntrinsicWidth(){
            return  27;//the width you want
        }

        @Override
        public int getIntrinsicHeight(){
            return  19;// the height you want
        }
    };

- batsheva