通过向下拖动,BottomSheetDialog在解除后仍然隐藏

Question

我很好奇BottomSheetDialog它被解雇时的行为:当用户向下拖动它以隐藏它时,它将保持隐藏,即使bottomSheetDialog#show()被调用.这仅在拖动时发生,而不是在用户触摸外部或bottomSheetDialog#dismiss()以编程方式调用时发生.

这真的很烦人,因为我内部有一个非常大bottomSheetDialog的回收视图,每次我想展示它时我都要创建一个新的bottomSheetDialog.

所以不要只是这样做:

if(bottomSheetDialog != null){
   bottomSheetDialog.show();
else{
   createNewBottomSheetDialog();
}

我每次都要创建一个.

我错过了什么或者这是正常行为吗？(顺便说一句,我用appcompat-v7:23.2.1)

Answer 1

所以我终于设法通过直接查看BottomSheetDialog实现来解决这个问题,我发现它只是一个简单的Dialog包装成常规BottomSheet.
问题在于BottomSheetCallBack:

@Override
    public void onStateChanged(@NonNull View bottomSheet,
            @BottomSheetBehavior.State int newState) {
        if (newState == BottomSheetBehavior.STATE_HIDDEN) {
            dismiss();
        }
    }

到达状态HIDDEN时会出现问题,当通过向下拖动对话框时会发生这种情况.之后,即使bottomSheetDialog.show()被调用,对话框也会保持隐藏状态.我找到的最简单的修复方法是删除此状态并将其替换为COLLAPSED状态.

我创建了一个classCustomBottomSheetDialog,复制了整个BottomSheetDialog类并添加了一行来解决问题:

@Override
    public void onStateChanged(@NonNull View bottomSheet,
                               @BottomSheetBehavior.State int newState) {

        if (newState == CustomBottomSheetBehavior.STATE_HIDDEN) {

            dismiss();
            bottomSheetBehavior.setState(CustomBottomSheetBehavior.STATE_COLLAPSED);
        }
    }

这是最终的代码:

public class CustomBottomSheetDialog extends AppCompatDialog {

    public CustomBottomSheetDialog (@NonNull Context context) {
        this(context, 0);
    }

    public CustomBottomSheetDialog (@NonNull Context context, @StyleRes int theme) {
        super(context, getThemeResId(context, theme));
        // We hide the title bar for any style configuration. Otherwise, there will be a gap
        // above the bottom sheet when it is expanded.
        supportRequestWindowFeature(Window.FEATURE_NO_TITLE);
    }

    protected CustomBottomSheetDialog (@NonNull Context context, boolean cancelable,
            OnCancelListener cancelListener) {
        super(context, cancelable, cancelListener);
        supportRequestWindowFeature(Window.FEATURE_NO_TITLE);
    }

    @Override
    public void setContentView(@LayoutRes int layoutResId) {
        super.setContentView(wrapInBottomSheet(layoutResId, null, null));
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getWindow().setLayout(
                ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
    }

    @Override
    public void setContentView(View view) {
        super.setContentView(wrapInBottomSheet(0, view, null));
    }

    @Override
    public void setContentView(View view, ViewGroup.LayoutParams params) {
        super.setContentView(wrapInBottomSheet(0, view, params));
    }

    private View wrapInBottomSheet(int layoutResId, View view, ViewGroup.LayoutParams params) {
        final CoordinatorLayout coordinator = (CoordinatorLayout) View.inflate(getContext(),
                R.layout.design_bottom_sheet_dialog, null);
        if (layoutResId != 0 && view == null) {
            view = getLayoutInflater().inflate(layoutResId, coordinator, false);
        }
        FrameLayout bottomSheet = (FrameLayout) coordinator.findViewById(R.id.design_bottom_sheet);
        BottomSheetBehavior.from(bottomSheet).setBottomSheetCallback(mBottomSheetCallback);
        if (params == null) {
            bottomSheet.addView(view);
        } else {
            bottomSheet.addView(view, params);
        }
        // We treat the CoordinatorLayout as outside the dialog though it is technically inside
        if (shouldWindowCloseOnTouchOutside()) {
            coordinator.findViewById(R.id.touch_outside).setOnClickListener(
                    new View.OnClickListener() {
                        @Override
                        public void onClick(View view) {
                            if (isShowing()) {
                                cancel();
                            }
                        }
                    });
        }
        return coordinator;
    }

    private boolean shouldWindowCloseOnTouchOutside() {
        if (Build.VERSION.SDK_INT < 11) {
            return true;
        }
        TypedValue value = new TypedValue();
        //noinspection SimplifiableIfStatement
        if (getContext().getTheme()
                .resolveAttribute(android.R.attr.windowCloseOnTouchOutside, value, true)) {
            return value.data != 0;
        }
        return false;
    }

    private static int getThemeResId(Context context, int themeId) {
        if (themeId == 0) {
            // If the provided theme is 0, then retrieve the dialogTheme from our theme
            TypedValue outValue = new TypedValue();
            if (context.getTheme().resolveAttribute(
                    R.attr.bottomSheetDialogTheme, outValue, true)) {
                themeId = outValue.resourceId;
            } else {
                // bottomSheetDialogTheme is not provided; we default to our light theme
                themeId = R.style.Theme_Design_Light_BottomSheetDialog;
            }
        }
        return themeId;
    }

    private BottomSheetBehavior.BottomSheetCallback mBottomSheetCallback
            = new BottomSheetBehavior.BottomSheetCallback() {
        @Override
        public void onStateChanged(@NonNull View bottomSheet,
                @BottomSheetBehavior.State int newState) {
            if (newState == BottomSheetBehavior.STATE_HIDDEN) {
                dismiss();
                bottomSheetBehavior.setState(CustomBottomSheetBehavior.STATE_COLLAPSED);
            }
        }

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

}

Answer 2

更新:某个版本的支持库已解决该问题.我真的不知道修复它的确切版本,但在27.0.2中修复了它.

注意:由于Google对网址架构进行了一些修改,因此网址不再引用所述问题.

一种解决方法比复制整个类只是为了添加一行更好

// Fix BottomSheetDialog not showing after getting hidden when the user drags it down
    myBottomSheetDialog.setOnShowListener(new DialogInterface.OnShowListener() {
        @Override
        public void onShow(DialogInterface dialogInterface) {
            BottomSheetDialog bottomSheetDialog = (BottomSheetDialog) dialogInterface;
            FrameLayout bottomSheet = (FrameLayout) bottomSheetDialog
                    .findViewById(android.support.design.R.id.design_bottom_sheet);
            BottomSheetBehavior.from(bottomSheet).setState(BottomSheetBehavior.STATE_COLLAPSED);
        }
    });

请参阅:https://code.google.com/p/android/issues/detail？id = 202396#c7