How to move the Android Spinner drop down arrow cl

问题:

I need to set the drop down arrow closer to its emitting text element in Spinner. How can achieve this?

<Spinner android:id="@+id/spinner"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content" />

回答1:

You can fix this by defining a custom background in xml, and then setting the arrow's margin from the right side.

Start by defining a layer-list with a rectangle background and a bitmap object for your arrow. You can make the arrow align to the center on the right side by setting its gravity, and you can move it towards the center by setting its right margin via the android:"right" attribute. Note that this won't dynamically move the arrow based on the length of text, but it should be a helpful first step.

spinner_background.xml

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape android:shape="rectangle">
            <solid android:color="@color/color_white" />
            <corners android:radius="2.5dp" />
        </shape>
    </item>
    <item android:right="64dp">
         <bitmap 
             android:gravity="right|center_vertical"  
             android:src="@drawable/ic_spinner" />
    </item>
</layer-list>

回答2:

This can be achieved by creating a custom layout for the selected spinner item custom_spinner_item.xml. I have added a TextView which displays the currently selected spinner item. The arrow icon is added in an ImageView. You can use any icon. The arrow icon moves depending on the length of the text which is not achieved by TheoKanning's answer. In fact you can completely modify the look of your spinner in this layout.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center_vertical"
    android:orientation="horizontal">
    <TextView
        android:id="@+id/spinner_item_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_vertical"
        android:paddingLeft="10dp"
        android:paddingRight="10dp"/>
    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_vertical"
        android:src="@mipmap/ic_arrow_down"/>
</LinearLayout>

Create a custom spinner adapter and inflate the above view. Also set the text of your selected spinner item from your list by overriding the default getView() method.

public class CustomSpinnerAdapter extends ArrayAdapter<String> {
    LayoutInflater inflater;
    List<String> spinnerItems;

    public CustomSpinnerAdapter(Context applicationContext, int resource, List<String> spinnerItems) {
        super(applicationContext, resource, spinnerItems);
        this.spinnerItems = spinnerItems;
        inflater = (LayoutInflater.from(applicationContext));
    }
    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {
        view = inflater.inflate(R.layout.custom_spinner_item, null);
        TextView type = (TextView) view.findViewById(R.id.spinner_item_text);
        type.setText(spinnerItems.get(i));
        return view;
    }
}

Then instantiate the CustomSpinnerAdapter class and set it as your spinner's adapter. spinnerList is the list of items to be shown in the spinner.

CustomSpinnerAdapter customSpinnerAdapter = new CustomSpinnerAdapter(getContext(), android.R.layout.simple_spinner_item, spinnerList);
spinner.setAdapter(customSpinnerAdapter);

回答3:

This layout will help you perfectly.

<FrameLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="@dimen/dp5"
    android:background="@drawable/squre_gray_bg"
    android:paddingRight="@dimen/dp10">

    <Spinner
        android:id="@+id/ed_project_start"
        android:layout_width="match_parent"
        android:layout_height="@dimen/dp40"
        android:layout_marginTop="@dimen/dp5"
        android:textColor="@color/colorDarkGray" />
</FrameLayout>

回答4:

1) Set the background of spinner to @null

<Spinner
     android:id="@+id/spinner"
     android:background="@null"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"/>

2) In the spinner adapter layout, create an Imageview to the right of Textview or whatever content is in there
 change the visibility of the imageview to "gone"

3)Override the onItemSelected method of the spinner in your activity,
 in the onItemSelected  method, call the Imageview 
    ImageView downArrow = (ImageView) view.findViewById(R.id.down_arrow);

change its visibility to "visible"