Is there an easy way to add a border to the top an

2018-12-31 16:54发布

I have a TextView and I'd like to add a black border along its top and bottom borders. I tried adding android:drawableTop and android:drawableBottom to the TextView, but that only caused the entire view to become black.

<TextView
    android:background="@android:color/green"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:drawableTop="@android:color/black"
    android:drawableBottom="@android:color/black"
    android:text="la la la" />

Is there a way to easily add a top and bottom border to a View (in particular, a TextView) in Android?

22条回答
查无此人
2楼-- · 2018-12-31 17:39

You can also use a 9-path to do your job. Create it so that colored pixel do not multiply in height but only the transparent pixel.

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余生请多指教
3楼-- · 2018-12-31 17:40

I've used a trick so that the border is displayed outside the container. With this trick only a line is drawn so the background will be shown of the underlying view.

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
    <item
        android:bottom="1dp"
        android:left="-2dp"
        android:right="-2dp"
        android:top="-2dp">
        <shape android:shape="rectangle" >
            <stroke
                android:width="1dp"
                android:color="#FF000000" />

            <solid android:color="#00FFFFFF" />

            <padding android:left="10dp"
                android:right="10dp"
                android:top="10dp"
                android:bottom="10dp" />
        </shape>
    </item>

</layer-list>
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零度萤火
4楼-- · 2018-12-31 17:42

Why not just create a 1dp high view with a background color? Then it can be easily placed where you want.

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与风俱净
5楼-- · 2018-12-31 17:43

In android 2.2 you could do the following.

Create an xml drawable such as /res/drawable/textlines.xml and assign this as a TextView's background property.

<TextView
android:text="My text with lines above and below"
android:background="@drawable/textlines"
/>

/res/drawable/textlines.xml

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
    <item>
      <shape 
        android:shape="rectangle">
            <stroke android:width="1dp" android:color="#FF000000" />
            <solid android:color="#FFDDDDDD" />

        </shape>
   </item>

   <item android:top="1dp" android:bottom="1dp"> 
      <shape 
        android:shape="rectangle">
            <stroke android:width="1dp" android:color="#FFDDDDDD" />
            <solid android:color="#00000000" />
        </shape>
   </item>

</layer-list>

The down side to this is that you have to specify an opaque background colour, as transparencies won't work. (At least i thought they did but i was mistaken). In the above example you can see that the solid colour of the first shape #FFffffdffffd is copied in the 2nd shapes stroke colour.

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栀子花@的思念
6楼-- · 2018-12-31 17:43

To add a 1dp white border at the bottom only and to have a transparent background you can use the following which is simpler than most answers here.

For the TextView or other view add:

android:background="@drawable/borderbottom"

And in the drawable directory add the following XML, called borderbottom.xml

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:top="-2dp" android:left="-2dp" android:right="-2dp">
        <shape android:shape="rectangle">
            <stroke android:width="1dp" android:color="#ffffffff" />
            <solid android:color="#00000000" />
        </shape>
    </item>
</layer-list>

If you want a border at the top, change the android:top="-2dp" to android:bottom="-2dp"

The colour does not need to be white and the background does not need to be transparent either.

The solid element may not be required. This will depend on your design (thanks V. Kalyuzhnyu).

Basically, this XML will create a border using the rectangle shape, but then pushes the top, right and left sides beyond the render area for the shape. This leaves just the bottom border visible.

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路过你的时光
7楼-- · 2018-12-31 17:47

You can also wrap the view in a FrameLayout, then set the frame's background color and padding to what you want; however, the textview, by default has a 'transparent' background, so you'd need to change the textview's background color too.

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