如何在Android中创建带有圆角边框的自定义视图

Question

Hi,

I'm trying to understand how to make custom view (with green background) on Android like represented on attached image. Please suggest, should I use Path for this or something else?

Answer 1

A good starting point would be http://tips.androidhive.info/2013/09/android-layout-rounded-corner-border/ . Then you can play with the attribute values to get the desired background. Hope this helps.

Answer 2

You have two good options for accomplishing this.

Bitmap

Create the desired image in Photoshop, Gimp or something similar. Export it as a png file then import it as a bitmap resource into your Android application.

This is by far the simpler and faster of the two methods, but here are two significant problems. First, you should supply bitmaps for each screen density bucket . Second, each bitmap resource you add increases the install size of your app. This can get out of hand quickly.

Path

As you mentioned in your question, you can draw the desired shape directly onto a canvas using a Path . More specifically, you'll use the cubicTo() method to create bezier curves.

I recommend using your image editor's "path" tool to learn how the control points affect the curve. Once you've drawn the shape in the image editor, write down the coordinates for every point on your path as well as the corresponding control points. Then do a little math to convert the points to ratios of the image's overall width and height.

You can implement the shape in your app as a View or as a Drawable . In either case, you'll be drawing to a Canvas . The important step will be to set up the path by multiplying the ratios with the size of your drawing area. After you draw the fancy edge, be sure to draw the straight edges via lineTo() and to close the shape with close() .