如何改变打开的微调器的位置? [英] How to change the position of opened spinner?

问题描述

我希望微调器下拉菜单在微调器本身的正下方打开.例如:

I would like the spinner dropdown to open right below the spinner itself. E.g.:

如何设置微调下拉框的位置?

How can i set the position of spinner dropdown?

推荐答案

您必须扩展 Spinner 并更改 AlertDialog 的位置(点击时的 Spinner 充当 alertDialog).

You have to extend Spinner and change the location of AlertDialog (spinner when clicked acts as alertDialog).

代码(不仅仅是定位，它还为打开的微调器设置背景):

Code (does a bit more than just position, it also sets background for opened spinner):

public class CustomSpinner extends Spinner {

private AlertDialog mPopup;

public CustomSpinner(Context context) {
    super(context);
}

public CustomSpinner(Context context, AttributeSet attrs) {
    super(context, attrs);
}

public CustomSpinner(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
}

@Override
protected void onAttachedToWindow() {
    super.onAttachedToWindow();
}

@Override
protected void onDetachedFromWindow() {
    super.onDetachedFromWindow();

    if (mPopup != null && mPopup.isShowing()) {
        mPopup.dismiss();
        mPopup = null;
    }
}


//when clicked alertDialog is made
@Override
public boolean performClick() {
    Context context = getContext();

    AlertDialog.Builder builder = new AlertDialog.Builder(context);
    CharSequence prompt = getPrompt();
    if (prompt != null) {
        builder.setTitle(prompt);
    }



    mPopup = builder.setSingleChoiceItems(
            new DropDownAdapter(getAdapter()),
            getSelectedItemPosition(), this).show();

    WindowManager.LayoutParams WMLP = mPopup.getWindow().getAttributes();

            //width and height must be set to anything other than WRAP_CONTENT!
    WMLP.x = 0; // x position
    WMLP.y = 50; // y position
    WMLP.height =390 ; //LayoutParams.WRAP_CONTEN
    WMLP.width = 315;
    WMLP.horizontalMargin = 0; 
    WMLP.verticalMargin = 0;

    mPopup.getWindow().setAttributes(WMLP);



    //ListView.getDefaultSize(size, measureSpec)
    ListView listView = mPopup.getListView();
    //listView.set
    // Remove divider between rows
    listView.setDivider(null);

    // Set custom background
    listView.setBackgroundResource(R.drawable.drop);

    // Remove background from all (grand)parent's
    ViewParent parent = listView.getParent();
    while (parent != null && parent instanceof View) {
        ((View) parent).setBackgroundDrawable(null);

        parent = parent.getParent();
    }

    return true;
}

@Override
public void onClick(DialogInterface dialog, int which) {
    setSelection(which);
    dialog.dismiss();
    mPopup = null;
}


 * <p>Wrapper class for an Adapter. Transforms the embedded Adapter instance
 * into a ListAdapter.</p>
 */
private static class DropDownAdapter implements ListAdapter, SpinnerAdapter {
    private SpinnerAdapter mAdapter;

    /**
     * <p>Creates a new ListAddapter wrapper for the specified adapter.</p>
     *
     * @param adapter the Adapter to transform into a ListAdapter
     */
    public DropDownAdapter(SpinnerAdapter adapter) {
        this.mAdapter = adapter;
    }

    public int getCount() {
        return mAdapter == null ? 0 : mAdapter.getCount();
    }

    public Object getItem(int position) {
        return mAdapter == null ? null : mAdapter.getItem(position);
    }

    public long getItemId(int position) {
        return mAdapter == null ? -1 : mAdapter.getItemId(position);
    }

    public View getView(int position, View convertView, ViewGroup parent) {
        return getDropDownView(position, convertView, parent);
    }

    public View getDropDownView(int position, View convertView, ViewGroup parent) {
        return mAdapter == null ? null :
                mAdapter.getDropDownView(position, convertView, parent);
    }

    public boolean hasStableIds() {
        return mAdapter != null && mAdapter.hasStableIds();
    }

    public void registerDataSetObserver(DataSetObserver observer) {
        if (mAdapter != null) {
            mAdapter.registerDataSetObserver(observer);
        }
    }

    public void unregisterDataSetObserver(DataSetObserver observer) {
        if (mAdapter != null) {
            mAdapter.unregisterDataSetObserver(observer);
        }
    }

    /**
     * <p>Always returns false.</p>
     *
     * @return false
     */
    public boolean areAllItemsEnabled() {
        return true;
    }

    /**
     * <p>Always returns false.</p>
     *
     * @return false
     */
    public boolean isEnabled(int position) {
        return true;
    }

    public int getItemViewType(int position) {
        return 0;
    }

    public int getViewTypeCount() {
        return 1;
    }

    public boolean isEmpty() {
        return getCount() == 0;
    }

   }
   }

然后你只需要使用yourPackage.CustomSpinner"元素将它插入到你的布局中，例如:

Then you just gotta insert it to your layout with "yourPackage.CustomSpinner" element like:

<yourPackage.CustomSpinner 
     android:layout_height="wrap_content"
     android:id="@+id/spinner" 
     android:layout_width="fill_parent">
</yourPackage.CustomSpinner>

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