我有类似的要求，并花了一些时间查看ActionBarDrawerToggle 代码。你目前拥有的是最好的前进方式。
更多内容：
汉堡到箭头的动画由可绘制实现提供 - DrawerArrowDrawableToggle。目前，我们对这个可绘制对象如何响应抽屉状态没有太多控制。 actionVarDrawerToggle 的包访问构造函数是这样说的：
/**
* In the future, we can make this constructor public if we want to let developers customize
* the
* animation.
*/
<T extends Drawable & DrawerToggle> ActionBarDrawerToggle(Activity activity, Toolbar toolbar,
DrawerLayout drawerLayout, T slider,
@StringRes int openDrawerContentDescRes,
@StringRes int closeDrawerContentDescRes)
通过提供您自己的slider 实现，您可以控制它对抽屉状态的反应方式。 slider必须实现的接口：
/**
* Interface for toggle drawables. Can be public in the future
*/
static interface DrawerToggle {
public void setPosition(float position);
public float getPosition();
}
setPosition(float) 是这里的亮点 - 所有抽屉状态更改都会调用它来更新抽屉指示器。
对于您想要的行为，您的 slider 实现的 setPosition(float position) 不会做任何事情。
你仍然需要：
if (showHomeAsUp) {
mDrawerToggle.setDrawerIndicatorEnabled(false);
// Can be set in theme
mDrawerToggle.setHomeAsUpIndicator(R.drawable.lib_ic_arrow_back_light);
mDrawerToggle.setToolbarNavigationClickListener(view -> finish());
}
如果你不setDrawerIndicatorEnabled(false)，你用setToolbarNavigationClickListener(view -> finish());设置的OnClickListener不会触发。
我们现在可以做些什么？
经过仔细检查，我发现ActionBarDrawerToggle 中有满足您的要求的规定。我发现这个条款比你现在拥有的更多。但是，我会让你决定。
ActionBarDrawerToggle 允许您通过接口Delegate 对抽屉指示器进行一些控制。您可以通过以下方式让您的活动实现此接口：
public class TheActivity extends ActionBarActivity implements ActionBarDrawerToggle.Delegate {
....
@Override
public void setActionBarUpIndicator(Drawable drawableNotUsed, int i) {
// First, we're not using the passed drawable, the one that animates
// Second, we check if `displayHomeAsUp` is enabled
final boolean displayHomeAsUpEnabled = (getSupportActionBar().getDisplayOptions()
& ActionBar.DISPLAY_HOME_AS_UP) == ActionBar.DISPLAY_HOME_AS_UP;
// We'll control what happens on navigation-icon click
mToolbar.setNavigationOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (displayHomeAsUpEnabled) {
finish();
} else {
// `ActionBarDrawerToggle#toggle()` is private.
// Extend `ActionBarDrawerToggle` and make provision
// for toggling.
mDrawerToggle.toggleDrawer();
}
}
});
// I will talk about `mToolbarnavigationIcon` later on.
if (displayHomeAsUpEnabled) {
mToolbarNavigationIcon.setIndicator(
CustomDrawerArrowDrawable.HOME_AS_UP_INDICATOR);
} else {
mToolbarNavigationIcon.setIndicator(
CustomDrawerArrowDrawable.DRAWER_INDICATOR);
}
mToolbar.setNavigationIcon(mToolbarNavigationIcon);
mToolbar.setNavigationContentDescription(i);
}
@Override
public void setActionBarDescription(int i) {
mToolbar.setNavigationContentDescription(i);
}
@Override
public Drawable getThemeUpIndicator() {
final TypedArray a = mToolbar.getContext()
.obtainStyledAttributes(new int[]{android.R.attr.homeAsUpIndicator});
final Drawable result = a.getDrawable(0);
a.recycle();
return result;
}
@Override
public Context getActionBarThemedContext() {
return mToolbar.getContext();
}
....
}
ActionBarDrawerToggle 将使用此处提供的setActionBarUpIndicator(Drawable, int)。由于我们忽略了正在传递的Drawable，因此我们可以完全控制将显示的内容。
Catch：如果我们在此处将 Toolbar 参数作为 null 传递，ActionBarDrawerToggle 将让我们的 Activity 充当代理：
public ActionBarDrawerToggle(Activity activity, DrawerLayout drawerLayout,
Toolbar toolbar, @StringRes int openDrawerContentDescRes,
@StringRes int closeDrawerContentDescRes) { .... }
而且，您需要在活动中覆盖 getV7DrawerToggleDelegate()：
@Nullable
@Override
public ActionBarDrawerToggle.Delegate getV7DrawerToggleDelegate() {
return this;
}
如您所见，走正确的路需要做很多额外的工作。我们还没有完成。
动画DrawerArrowDrawableToggle 可以使用these attributes 设置样式。如果您希望您的可绘制状态（homeAsUp & hamburger）完全像默认值一样，您需要这样实现它：
/**
* A drawable that can draw a "Drawer hamburger" menu or an Arrow
*/
public class CustomDrawerArrowDrawable extends Drawable {
public static final float DRAWER_INDICATOR = 0f;
public static final float HOME_AS_UP_INDICATOR = 1f;
private final Activity mActivity;
private final Paint mPaint = new Paint();
// The angle in degress that the arrow head is inclined at.
private static final float ARROW_HEAD_ANGLE = (float) Math.toRadians(45);
private final float mBarThickness;
// The length of top and bottom bars when they merge into an arrow
private final float mTopBottomArrowSize;
// The length of middle bar
private final float mBarSize;
// The length of the middle bar when arrow is shaped
private final float mMiddleArrowSize;
// The space between bars when they are parallel
private final float mBarGap;
// Use Path instead of canvas operations so that if color has transparency, overlapping sections
// wont look different
private final Path mPath = new Path();
// The reported intrinsic size of the drawable.
private final int mSize;
private float mIndicator;
/**
* @param context used to get the configuration for the drawable from
*/
public CustomDrawerArrowDrawable(Activity activity, Context context) {
final TypedArray typedArray = context.getTheme()
.obtainStyledAttributes(null, R.styleable.DrawerArrowToggle,
R.attr.drawerArrowStyle,
R.style.Base_Widget_AppCompat_DrawerArrowToggle);
mPaint.setAntiAlias(true);
mPaint.setColor(typedArray.getColor(R.styleable.DrawerArrowToggle_color, 0));
mSize = typedArray.getDimensionPixelSize(R.styleable.DrawerArrowToggle_drawableSize, 0);
mBarSize = typedArray.getDimension(R.styleable.DrawerArrowToggle_barSize, 0);
mTopBottomArrowSize = typedArray
.getDimension(R.styleable.DrawerArrowToggle_topBottomBarArrowSize, 0);
mBarThickness = typedArray.getDimension(R.styleable.DrawerArrowToggle_thickness, 0);
mBarGap = typedArray.getDimension(R.styleable.DrawerArrowToggle_gapBetweenBars, 0);
mMiddleArrowSize = typedArray
.getDimension(R.styleable.DrawerArrowToggle_middleBarArrowSize, 0);
typedArray.recycle();
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.SQUARE);
mPaint.setStrokeWidth(mBarThickness);
mActivity = activity;
}
public boolean isLayoutRtl() {
return ViewCompat.getLayoutDirection(mActivity.getWindow().getDecorView())
== ViewCompat.LAYOUT_DIRECTION_RTL;
}
@Override
public void draw(Canvas canvas) {
Rect bounds = getBounds();
final boolean isRtl = isLayoutRtl();
// Interpolated widths of arrow bars
final float arrowSize = lerp(mBarSize, mTopBottomArrowSize, mIndicator);
final float middleBarSize = lerp(mBarSize, mMiddleArrowSize, mIndicator);
// Interpolated size of middle bar
final float middleBarCut = lerp(0, mBarThickness / 2, mIndicator);
// The rotation of the top and bottom bars (that make the arrow head)
final float rotation = lerp(0, ARROW_HEAD_ANGLE, mIndicator);
final float topBottomBarOffset = lerp(mBarGap + mBarThickness, 0, mIndicator);
mPath.rewind();
final float arrowEdge = -middleBarSize / 2;
// draw middle bar
mPath.moveTo(arrowEdge + middleBarCut, 0);
mPath.rLineTo(middleBarSize - middleBarCut, 0);
final float arrowWidth = Math.round(arrowSize * Math.cos(rotation));
final float arrowHeight = Math.round(arrowSize * Math.sin(rotation));
// top bar
mPath.moveTo(arrowEdge, topBottomBarOffset);
mPath.rLineTo(arrowWidth, arrowHeight);
// bottom bar
mPath.moveTo(arrowEdge, -topBottomBarOffset);
mPath.rLineTo(arrowWidth, -arrowHeight);
mPath.moveTo(0, 0);
mPath.close();
canvas.save();
if (isRtl) {
canvas.rotate(180, bounds.centerX(), bounds.centerY());
}
canvas.translate(bounds.centerX(), bounds.centerY());
canvas.drawPath(mPath, mPaint);
canvas.restore();
}
@Override
public void setAlpha(int i) {
mPaint.setAlpha(i);
}
// override
public boolean isAutoMirrored() {
// Draws rotated 180 degrees in RTL mode.
return true;
}
@Override
public void setColorFilter(ColorFilter colorFilter) {
mPaint.setColorFilter(colorFilter);
}
@Override
public int getIntrinsicHeight() {
return mSize;
}
@Override
public int getIntrinsicWidth() {
return mSize;
}
@Override
public int getOpacity() {
return PixelFormat.TRANSLUCENT;
}
public void setIndicator(float indicator) {
mIndicator = indicator;
invalidateSelf();
}
/**
* Linear interpolate between a and b with parameter t.
*/
private static float lerp(float a, float b, float indicator) {
if (indicator == HOME_AS_UP_INDICATOR) {
return b;
} else {
return a;
}
}
}
CustomDrawerArrowDrawable's 的实现是从 AOSP 借来的，并被精简为只允许绘制两个状态：homeAsUp 和 hamburger。您可以通过调用setIndicator(float) 在这些状态之间切换。我们在我们实现的Delegate 中使用了它。此外，使用CustomDrawerArrowDrawable 将允许您在xml 中设置样式：barSize、color 等。即使您不需要它，上面的实现让您为抽屉打开和关闭提供自定义动画。
我真的不知道我是否应该推荐这个。
如果您使用参数null 调用ActionBarDrawerToggle#setHomeAsUpIndicator(...)，它应该选择在您的主题中定义的drawable：
<item name="android:homeAsUpIndicator">@drawable/some_back_drawable</item>
目前，这不会发生，因为ToolbarCompatDelegate#getThemeUpIndicator() 中可能存在错误：
@Override
public Drawable getThemeUpIndicator() {
final TypedArray a = mToolbar.getContext()
// Should be new int[]{android.R.attr.homeAsUpIndicator}
.obtainStyledAttributes(new int[]{android.R.id.home});
final Drawable result = a.getDrawable(0);
a.recycle();
return result;
}
松散讨论此问题的错误报告（阅读案例 4）：Link
如果您决定坚持使用已有的解决方案，请考虑使用CustomDrawerArrowDrawable 代替 pngs(R.drawable.lib_ic_arrow_back_light & R.drawable.lib_ic_menu_light)。您将不需要用于密度/大小桶的多个可绘制对象，并且样式将在 xml 中完成。此外，最终产品将与框架的相同。
mDrawerToggle.setDrawerIndicatorEnabled(false);
CustomDrawerArrowDrawable toolbarNavigationIcon
= new CustomDrawerArrowDrawable(this, mToolbar.getContext());
if (showHomeAsUp) {
toolbarNavigationIcon.setIndicator(
CustomDrawerArrowDrawable.HOME_AS_UP_INDICATOR);
mDrawerToggle.setToolbarNavigationClickListener(view -> finish());
} else {
mToolbarNavigationIcon.setIndicator(
CustomDrawerArrowDrawable.DRAWER_INDICATOR);
mDrawerToggle.setToolbarNavigationClickListener(view -> toggleDrawer());
}
mDrawerToggle.setHomeAsUpIndicator(toolbarNavigationIcon);