Android使用Tint为图标Icon动态着色的操作方法

<ImageView
    ...
    android:src="@drawable/icon_filter_black" />

// XXXFragment.kt

imageView.setImageDrawable(
    if (isSelect) {
        // 筛选后为橙色
        resources.getDrawable(R.drawable.icon_filter_orange);
    } else {
        // 未筛选为黑色
        resources.getDrawable(R.drawable.icon_filter_black);
    }
)

<ImageView
    ...
    android:src="@drawable/icon_filter" 
    app:tint="@color/black"
    />

imageView.imageTintList = ColorStateList(...)

val drawable = resources.getDrawable(R.drawable.icon_filter)
drawable.setTint = Color.BLACK

imageView.setImageDrawable(drawable)

 // ImageView.java
public void setImageTintList(@Nullable ColorStateList tint) {
    mDrawableTintList = tint;
    mHasDrawableTint = true;
    
    applyImageTint();
}

private void applyImageTint() {
    if (mDrawable != null && (mHasDrawableTint || mHasDrawableBlendMode)) {
        mDrawable = mDrawable.mutate();
        
        if (mHasDrawableTint) {
            mDrawable.setTintList(mDrawableTintList); // 将 tint 传递给 Drawable！
        }
        // ...
    }
}

public class VectorDrawable extends Drawable {
    private BlendModeColorFilter mBlendModeColorFilter ;
    
    @Override
    public void setTintList(ColorStateList tint) {
        // 使用 tint 创建 ColorFilter
        updateColorFilters(... , tint) ;
    }
    
    private void updateColorFilters(@Nullable BlendMode blendMode , ColorStateList tint) {
        // ...
    mBlendModeColorFilter = updateBlendModeFilter(mBlendModeColorFilter , tint , blendMode) ;
    }
    
    @Override
    public void draw(Canvas canvas) {
        // 绘制时，如果外部没有设置 mColorFilter，则使用 mBlendModeColorFilter
        final ColorFilter colorFilter = (mColorFilter == null ? mBlendModeColorFilter : mColorFilter) ;
        // ...
    }
}

public abstract class Drawable {
    @Nullable 
    BlendModeColorFilter updateBlendModeFilter(@Nullable ColorStateList tint , ... ) {
        // ... 
        final int color = tint.getColorForState(getState() , Color.TRANSPARENT) ;
    
        if (blendFilter == null || blendFilter.getColor() != color
                || blendFilter.getMode() != blendMode) {
            return new BlendModeColorFilter(color , blendMode) ;
        }
        
        return blendFilter ;
    }
}

<ImageView
    ...
    android:src="@drawable/icon_filter"
    app:tint="@color/black"
    />

val drawable = resources.getDrawable(R.drawable.icon_filter)
drawable.setTint = Color.YELLOW

imageView.setImageDrawable(drawable)

// ImageView.kt

public void setImageDrawable(@Nullable Drawable drawable) {
    updateDrawable(drawable) ;
}

private void updateDrawable(Drawable d) {
    applyImageTint() ;
}

private void applyImageTint() {
    if (mHasDrawableTint) {
        mDrawable.setTintList(mDrawableTintList) ;
    }
}