Android EditText+ListPopupWindow实现可编辑的下拉列表

使用场景

AutoCompleteEditText只有开始输入并且与输入的字符有匹配的时候才弹出下拉列表.Spinner的缺点是不可以编辑.所以本文介绍如何使用EditText+ListPopupWindow实现可编辑的下拉列表.使用场景可以是有记住密码功能的登录框.

给EditText增加上下箭头

我们需要一个箭头图片,放在EditText的右面,用来点击后弹出下拉列表.如图所示

要想实现这个很容易,只需要在布局文件中给EditText设置一个drawableRight的属性.

<EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:drawableRight="@drawable/pull_down1"/>

如何在点击的时候切换箭头的方向

切换箭头的上下方向,实际上就是重新设置EditText的drawableRight.这就需要动态的设置EditText的drawableRight.

setCompoundDrawables(left, top, right, bottom);
setCompoundDrawablesWithIntrinsicBounds(left, top, right, bottom);

意思是设置Drawable显示在text的左、上、右、下位置。

但是两者有些区别： 
setCompoundDrawables 画的drawable的宽高是按drawable.setBound()设置的宽高，所以才有The Drawables must already have had setBounds(Rect) called.意思是说使用之前必须使用Drawable.setBounds设置Drawable的长宽。 
而setCompoundDrawablesWithIntrinsicBounds是画的drawable的宽高是按drawable固定的宽高，即通过getIntrinsicWidth()与getIntrinsicHeight()获得，所以才有The Drawables’ bounds will be set to their intrinsic bounds.这句话之说！

例如:

editTest.setCompoundDrawablesWithIntrinsicBounds(getResources().getDrawable(R.drawable.test), null, null, null);

给EditText添加触摸监听事件,当点击到drawableRight部位的时候,就重新设置图片资源

editText.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View view, MotionEvent event) {
                final int DRAWABLE_LEFT = ;
                final int DRAWABLE_TOP = ;
                final int DRAWABLE_RIGHT = ;
                final int DRAWABLE_BOTTOM = ;
                if (event.getAction() == MotionEvent.ACTION_UP) {
                    if (event.getX() >= (editText.getWidth() - editText
                            .getCompoundDrawables()[DRAWABLE_RIGHT].getBounds().width())) {
                        // your action here
                        editText.setCompoundDrawablesWithIntrinsicBounds(null, null, getResources().getDrawable(R.drawable.pull_up1), null);
                        return true;
                    }
                }
                return false;
            }
        });

ListPopupWindow

最后一步就是显示列表了

private void showListPopulWindow(){
        String[] list = { "item1", "item2", "item3", "item4" };
        listPopupWindow = new ListPopupWindow(this);
        listPopupWindow.setAdapter(new ArrayAdapter<String>(this,
                android.R.layout.simple_list_item_1, list));
        listPopupWindow.setAnchorView(editText);
        listPopupWindow.setModal(true);
        listPopupWindow.show();
    }

可以给listPopupWindow 设置监听事件,当item被选择的时候干啥,当listPopupWindow消失的时候干啥

listPopupWindow.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                editText.setText(list[i]);
            }
        });
listPopupWindow.setOnDismissListener(new PopupWindow.OnDismissListener() {
            @Override
            public void onDismiss() {
                editText.setCompoundDrawablesWithIntrinsicBounds(null, null, getResources().getDrawable(R.drawable.pull_down1), null);
            }
        });