Android 自定义Button 圆角大小可设置+点击变暗效果

Posted 2023-04-08

参考技术A 这里推荐一下大佬的框架，xml中直接实现shape： ShapeView

Android圆角图片

Android圆角图片

相比较于iOS实现圆角图片，Android的方式还是复杂些???

参考How to make an ImageView with rounded corners?

1.绘制圆角矩形，在绘制bitmap，通过设置setXfermode为SRC_IN来实现

setXfermode相关解释可参考HenCoder Android 开发进阶: 自定义 View 1-2 Paint 详解

如下的代码：

    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mImageView = (ImageView) findViewById(R.id.imageView);
        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.facebook);
        mImageView.setImageBitmap(getRoundedCornerBitmap(bitmap, 100));


    

    private Bitmap getRoundedCornerBitmap(Bitmap bitmap, int pixels) 

        Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(output);

        Paint paint = new Paint();
        Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
        RectF rectF = new RectF(rect);
        float roundPx = pixels;

        paint.setAntiAlias(true);
        canvas.drawARGB(0, 0, 0, 0);
        paint.setColor(Color.RED);//颜色随便设？
        canvas.drawRoundRect(rectF, roundPx , roundPx, paint);

        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
        canvas.drawBitmap(bitmap, rect, rect, paint);

        return output;

    

其它

• Android圆角图片和圆形图片实现总结