Change <layer-item> items by Java code

问题:

I have the following XML:

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">

<item android:id="@+id/customPlayerProgressBg">
    <shape>
        <gradient
                android:startColor="#FF999999"
                android:endColor="#FF999999"
        />
    </shape>
</item>

<item android:id="@+id/customPlayerProgressSecondary">
    <clip>
        <shape>
            <gradient
                    android:startColor="#FF5C3C68"
                    android:endColor="#FF5C3C68"
            />
        </shape>
    </clip>
</item>
<item
    android:id="@+id/customPlayerProgress"
>
    <clip>
        <shape>
            <gradient
                android:startColor="#FF5C3C68"
                android:endColor="#FF5C3C68"
            />
        </shape>
    </clip>
</item>

</layer-list>

I want to change the "customPlayerProgress" and the "customPlayerProgressSecondary" by Java code. How can that be accomplished?

回答1:

Assuming that you want to have access to them through Java code after they are loaded as a Drawable in your app, you should be able to do something like the following:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    final LayerDrawable ld = (LayerDrawable) getResources().getDrawable(R.drawable.my_drawable);
    final ClipDrawable d1 = (ClipDrawable) ld.findDrawableByLayerId(R.id.customPlayerProgress);
    final ClipDrawable d2 = (ClipDrawable) ld.findDrawableByLayerId(R.id.customPlayerProgressSecondary);

    /* modify ld, d1 and d2 by calling their methods here */
}

Also look at this for some more ideas.

回答2:

You can't change generated XML files at run-time.

回答3:

You may be familiar with DOM. You just need to modify the change and then save the file.

Here is an article that may be of some assistance.