android开发之自定义圆形ImagView

Posted 2021-12-16 mb61b711907d5f4

在日常使用中我们经常会使用到圆形的图片，但是android系统中并没有默认的圆形控件，所以我们需要自己来写一个自定义的ImagView来显示一张圆形的图片，下面先看效果

详细的方法是我们自定义一个类，继承ImagView，然后重写一些方法，下面是代码

/**

* 圆形的ImagView

*

* @author Administrator

*

*/

public class RoundImageView extends ImageView 

public RoundImageView(Context context) 

super(context);

// TODO Auto-generated constructor stub

public RoundImageView(Context context, AttributeSet attrs) 

super(context, attrs);

public RoundImageView(Context context, AttributeSet attrs, int defStyle) 

super(context, attrs, defStyle);

@Override

protected void onDraw(Canvas canvas) 

Drawable drawable = getDrawable();

if (drawable == null) 

return;

if (getWidth() == 0 || getHeight() == 0) 

return;

Bitmap b = ((BitmapDrawable) drawable).getBitmap();

if (null == b) 

return;

Bitmap bitmap = b.copy(Config.ARGB_8888, true);

int w = getWidth(), h = getHeight();

Bitmap roundBitmap = getCroppedBitmap(bitmap, w);

canvas.drawBitmap(roundBitmap, 0, 0, null);

public static Bitmap getCroppedBitmap(Bitmap bmp, int radius) 

Bitmap sbmp;

if (bmp.getWidth() != radius || bmp.getHeight() != radius)

sbmp = Bitmap.createScaledBitmap(bmp, radius, radius, false);

else

sbmp = bmp;

Bitmap output = Bitmap.createBitmap(sbmp.getWidth(), sbmp.getHeight(),

Config.ARGB_8888);

Canvas canvas = new Canvas(output);

final int color = 0xffa19774;

final Paint paint = new Paint();

final Rect rect = new Rect(0, 0, sbmp.getWidth(), sbmp.getHeight());

paint.setAntiAlias(true);

paint.setFilterBitmap(true);

paint.setDither(true);

canvas.drawARGB(0, 0, 0, 0);

//设置笔的颜色

paint.setColor(Color.parseColor("#BAB399"));

//画圆

canvas.drawCircle(sbmp.getWidth() / 2 + 0.5f,

sbmp.getHeight() / 2 + 0.5f, sbmp.getWidth() / 2 + 0.5f, paint);

paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));

canvas.drawBitmap(sbmp, rect, rect, paint);

return output;

然后在布局中引用这个自定义的控件， 就可以了

<里面的是你的包名加自定义的类名，如果按住Ctrl+鼠标左键能进入类的话，就说明引用成功了。

<comiptv.example.vincent.test.RoundImageView

android:layout_centerInParent="true"

android:src="@mipmap/a8"

android:layout_

android:layout_

/>

这样就可以了