17 自定义属性及圆角imageView

public class RoundAngleImageView extends ImageView {
    //cn.dpocket.moplusand.uinew是app的包名 manifest文件里面
    private static final String NAMESPACE = "http://schemas.android.com/apk/res/cn.dpocket.moplusand.uinew";
    private Paint paint;
    //如果不在xml属性里面设置自定义属性 默认值为5dp
    private int roundWidth = 5;
    private int roundHeight = 5;
    private Paint paint2;
    public RoundAngleImageView(Context context) {
        super(context);
        init(context,null);
    }

    public RoundAngleImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context,attrs);
    }

    private void init(Context context, AttributeSet attrs) {

        if(attrs != null) {
            roundWidth= attrs.getAttributeIntValue(NAMESPACE,"roundWidth",0);
            roundHeight= attrs.getAttributeIntValue(NAMESPACE, "roundHeight", 0);
        }else {
            float density = context.getResources().getDisplayMetrics().density;
            roundWidth = (int) (roundWidth*density);
            roundHeight = (int) (roundHeight*density);
        }

        paint = new Paint();
        paint.setColor(Color.WHITE);
        paint.setAntiAlias(true);
        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));

        paint2 = new Paint();
        paint2.setXfermode(null);
    }

    @Override
    public void draw(Canvas canvas) {
        Bitmap bitmap = Bitmap.createBitmap(getWidth(), getHeight(), Bitmap.Config.ARGB_8888);
        Canvas canvas2 = new Canvas(bitmap);
        super.draw(canvas2);
        drawLiftUp(canvas2);
        drawRightUp(canvas2);
        drawLiftDown(canvas2);
        drawRightDown(canvas2);
        canvas.drawBitmap(bitmap, 0, 0, paint2);
        bitmap.recycle();
    }

    private void drawLiftUp(Canvas canvas) {
        Path path = new Path();
        path.moveTo(0, roundHeight);
        path.lineTo(0, 0);
        path.lineTo(roundWidth, 0);
        path.arcTo(new RectF(
                        0,
                        0,
                        roundWidth*2,
                        roundHeight*2),
                -90,
                -90);
        path.close();
        canvas.drawPath(path, paint);
    }

    private void drawLiftDown(Canvas canvas) {
        Path path = new Path();
        path.moveTo(0, getHeight()-roundHeight);
        path.lineTo(0, getHeight());
        path.lineTo(roundWidth, getHeight());
        path.arcTo(new RectF(
                        0,
                        getHeight()-roundHeight*2,
                        0+roundWidth*2,
                        getHeight()),
                90,
                90);
        path.close();
        canvas.drawPath(path, paint);
    }

    private void drawRightDown(Canvas canvas) {
        Path path = new Path();
        path.moveTo(getWidth()-roundWidth, getHeight());
        path.lineTo(getWidth(), getHeight());
        path.lineTo(getWidth(), getHeight()-roundHeight);
        path.arcTo(new RectF(
                getWidth()-roundWidth*2,
                getHeight()-roundHeight*2,
                getWidth(),
                getHeight()), 0, 90);
        path.close();
        canvas.drawPath(path, paint);
    }

    private void drawRightUp(Canvas canvas) {
        Path path = new Path();
        path.moveTo(getWidth(), roundHeight);
        path.lineTo(getWidth(), 0);
        path.lineTo(getWidth()-roundWidth, 0);
        path.arcTo(new RectF(
                        getWidth()-roundWidth*2,
                        0,
                        getWidth(),
                        0+roundHeight*2),
                -90,
                90);
        path.close();
        canvas.drawPath(path, paint);
    }
}

定义一个attr.xml的文件，放在values目录下面，内容如下：

<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="RoundAngleImageView">
<attr name="roundWidth" format="integer" />
<attr name="roundHeight" format="integer" />
</declare-styleable>
</resources>

在布局文件的跟布局中 加入如下代码：

//cn.dpocket.moplusand.uinew是app的包名  manifest文件中

xmlns:app="http://schemas.android.com/apk/res/cn.dpocket.moplusand.uinew"

<cn.dpocket.moplusand.uinew.widget.RoundAngleImageView
                        android:id="@+id/iv_head1"
                        android:layout_width="68dp"
                        android:layout_height="68dp"    
                        app:roundWidth="8"
                        app:roundHeight="8"
                        ></cn.dpocket.moplusand.uinew.widget.RoundAngleImageView>