android - 更改 NinePatchDrawable 资源颜色

Question

我正在尝试设置 Spinner 元素的样式。我为此创建了带有图层列表的资源。我在那里使用标准库资源@drawable/abc_spinner_mtrl_am_alpha。它是一个箭头，它始终显示为白色。在android的api版本21中，在spinner中可以设置属性android:backgroundTint，但我不知道在早期版本中如何做到这一点。

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:bottom="4dp"
        android:left="4dp"
        android:right="4dp"
        android:top="4dp" >

        <shape android:shape="rectangle">
            <stroke
                android:color="#999"
                android:width="1dp" />
            <corners android:radius="2dip" />
            <solid android:color="@android:color/transparent"/>
        </shape>

    </item>

    <item android:id="@+id/notPressedSpinner"
        android:drawable="@drawable/abc_spinner_mtrl_am_alpha"
        android:right="4dp" />
</layer-list>

我尝试使用 setColorFilter 以编程方式更改资源，但它不起作用。

    Drawable abcSpinnerMtrlAmAlpha = mContext.getResources()
            .getDrawable(R.drawable.abc_spinner_mtrl_am_alpha);
    Drawable abcSpinnerMtrlAmAlpha2 = mContext.getResources()
            .getDrawable(R.drawable.abc_spinner_mtrl_am_alpha);

    abcSpinnerMtrlAmAlpha.setColorFilter(mContext.getResources().getColor(R.color.gray_color),
            PorterDuff.Mode.SRC_ATOP);
    abcSpinnerMtrlAmAlpha2.setColorFilter(mContext.getResources().getColor(R.color.green),
            PorterDuff.Mode.SRC_ATOP);

    LayerDrawable x = ((LayerDrawable)mContext.getResources().getDrawable(R.drawable.x));
    LayerDrawable y = ((LayerDrawable)mContext.getResources().getDrawable(R.drawable.y));

    x.setDrawableByLayerId(R.id.notPressedSpinner, abcSpinnerMtrlAmAlpha);
    y.setDrawableByLayerId(R.id.notPressedSpinner, abcSpinnerMtrlAmAlpha2);

Answer 1

我的解决方案

public class StateListDrawableWithTint extends StateListDrawable {
    private ColorStateList mColorStateList;
    private PorterDuff.Mode mFilterMode;

    public StateListDrawableWithTint(Drawable drawable, ColorStateList colorStateList) {
        this(drawable, colorStateList, PorterDuff.Mode.MULTIPLY);
    }

    public StateListDrawableWithTint(Drawable drawable, ColorStateList colorStateList, PorterDuff.Mode filterMode) {
        super();

        mColorStateList = colorStateList;
        mFilterMode = filterMode;

        addState(new int[]{}, drawable);
    }

    @Override
    protected boolean onStateChange(int[] states) {
        if (mColorStateList != null) {
            int stateColor = mColorStateList.getColorForState(states, Color.TRANSPARENT);

            super.setColorFilter(stateColor, mFilterMode);
        }

        return super.onStateChange(states);
    }
}

使用:

spinner.setBackgroundDrawable(new StateListDrawableWithTint(
                getResources().getDrawable(R.drawable.sum_currency_spinner),
                getResources().getColorStateList(R.color.sum_currency_spinner),
                PorterDuff.Mode.SRC_ATOP));

可绘制:

        <shape android:shape="rectangle">
            <stroke
                android:color="#999"
                android:width="1.5dp" />
            <corners android:radius="2dip" />
            <solid android:color="@android:color/transparent"/>
        </shape>

    </item>

    <item android:id="@+id/notPressedSpinner"
        android:drawable="@drawable/abc_spinner_mtrl_am_alpha"
        android:right="4dp" />
</layer-list>

颜色状态:

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <!-- disabled state -->
    <item android:state_enabled="false" android:color="@color/light_green"/>
    <!-- pressed state -->
    <item android:state_enabled="true" android:state_window_focused="true" android:state_pressed="true" android:color="@color/light_green" />
    <!-- unselected state -->
    <item android:state_enabled="true" android:state_window_focused="true" android:color="@color/gray_color" />
    <!-- dropdown list state -->
    <item android:state_enabled="true" android:state_focused="true" android:color="@color/light_green" />
    <!-- default -->
    <item android:color="@color/light_green" />
</selector>