BottomSheetBehavior非法状态参数：5

Question

有人可以解释这个异常何时发生？

12-18 11:20:07.225 15944-15944/com.test.dev.debug E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.dev.debug, PID: 15944
java.lang.IllegalArgumentException: Illegal state argument: 5
    at android.support.design.widget.BottomSheetBehavior.startSettlingAnimation(BottomSheetBehavior.java:631)
    at android.support.design.widget.BottomSheetBehavior$1.run(BottomSheetBehavior.java:550)
    at android.os.Handler.handleCallback(Handler.java:751)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:154)
    at android.app.ActivityThread.main(ActivityThread.java:6123)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:757)

Java类

public class BottomSheetController {

    private BottomSheetBehavior<View> bottomSheetBehavior;
    private WeakReference<FrameLayout> bottomSheetContainer;
    private Slide slide;

    public interface Slide {
        void onSlide(@NonNull View bottomSheet, float slideOffset);
    }

    public void bind(FrameLayout bottomSheetContainer) {
        this.bottomSheetContainer = new WeakReference<>(bottomSheetContainer);
        bottomSheetBehavior = BottomSheetBehavior.from(this.bottomSheetContainer.get());
        bottomSheetBehavior.setHideable(true);
        bottomSheetBehavior.setState(BottomSheetBehavior.STATE_HIDDEN);
        bottomSheetBehavior.setBottomSheetCallback(sheetCallback());
    }

    public void unbind() {
        this.bottomSheetContainer.clear();
    }

    public void setSlide(Slide slide) {
        this.slide = slide;
    }

    public void collapse() {
        bottomSheetBehavior.setHideable(true);
        bottomSheetBehavior.setState(BottomSheetBehavior.STATE_COLLAPSED);
    }

    public void expand() {
        bottomSheetBehavior.setHideable(false);
        bottomSheetBehavior.setState(BottomSheetBehavior.STATE_EXPANDED);
    }

    public void hide() {
        bottomSheetBehavior.setHideable(true);
        bottomSheetBehavior.setState(BottomSheetBehavior.STATE_HIDDEN);
    }

    public int getState() {
        return bottomSheetBehavior.getState();
    }

    private BottomSheetBehavior.BottomSheetCallback sheetCallback() {
        return new BottomSheetBehavior.BottomSheetCallback() {
            @Override
            public void onStateChanged(@NonNull View bottomSheet, int newState) {

                if (newState != BottomSheetBehavior.STATE_HIDDEN) {
                    bottomSheetBehavior.setHideable(false);
                } else {
                    bottomSheetBehavior.setHideable(true);
                }
            }

            @Override
            public void onSlide(@NonNull View bottomSheet, float slideOffset) {

                if (slide != null) {
                    slide.onSlide(bottomSheet, slideOffset);
                }
            }
        };
    }
}

Answer 1

public class IllegalArgumentException extends RuntimeException

抛出以指示方法已被传递非法或不适当的参数。

在代码中的某处，您将非法参数传递给方法startSettlingAnimation（）（BottomSheetBehavior类）。此方法抛出异常：

void startSettlingAnimation(View child, int state) {
    int top;
    if (state == STATE_COLLAPSED) {
      top = mCollapsedOffset;
    } else if (state == STATE_HALF_EXPANDED) {
      top = mHalfExpandedOffset;
    } else if (state == STATE_EXPANDED) {
      top = getExpandedOffset();
    } else if (mHideable && state == STATE_HIDDEN) {
      top = mParentHeight;
    } else {
      throw new IllegalArgumentException("Illegal state argument: " + state);
    }
    if (mViewDragHelper.smoothSlideViewTo(child, child.getLeft(), top)) {
      setStateInternal(STATE_SETTLING);
      ViewCompat.postOnAnimation(child, new SettleRunnable(child, state));
    } else {
      setStateInternal(state);
    }
  }

你的错误是：Illegal state argument: 5。 5是STATE_HIDDEN的int值。所以当你的状态是STATE_HIDDEN（5）时，你的mHideable布尔值是假的。所以，基本的建议是设置mHidable = true;

没有任何代码，这就像我可以告诉你的那样。