使用自定義ImageView，實現圓角功能

1.自定義屬性attrs.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="RoundCornerImageView">
        <attr name="radius" format="dimension" />
        <attr name="left_top_radius" format="dimension" />
        <attr name="right_top_radius" format="dimension" />
        <attr name="right_bottom_radius" format="dimension" />
        <attr name="left_bottom_radius" format="dimension" />
    </declare-styleable>
</resources>
 

2.自定義RoundCornerImageView，繼承AppCompatImageView

public class RoundCornerImageView extends AppCompatImageView {
    private float width, height;
    private int defaultRadius = 0;
    private int radius;
    private int leftTopRadius;
    private int rightTopRadius;
    private int rightBottomRadius;
    private int leftBottomRadius;


    public RoundCornerImageView(Context context) {
        this(context, null);
        init(context, null);
    }

    public RoundCornerImageView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
        init(context, attrs);
    }

    public RoundCornerImageView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context, attrs);
    }

    private void init(Context context, AttributeSet attrs) {
        if (Build.VERSION.SDK_INT < 18) {
            setLayerType(View.LAYER_TYPE_SOFTWARE, null);
        }
        // 讀取配置
        TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.RoundCornerImageView);
        radius = array.getDimensionPixelOffset(R.styleable.RoundCornerImageView_radius, defaultRadius);
        leftTopRadius = array.getDimensionPixelOffset(R.styleable.RoundCornerImageView_left_top_radius, defaultRadius);
        rightTopRadius = array.getDimensionPixelOffset(R.styleable.RoundCornerImageView_right_top_radius, defaultRadius);
        rightBottomRadius = array.getDimensionPixelOffset(R.styleable.RoundCornerImageView_right_bottom_radius, defaultRadius);
        leftBottomRadius = array.getDimensionPixelOffset(R.styleable.RoundCornerImageView_left_bottom_radius, defaultRadius);


        //如果四個角的值沒有設定，那麼就使用通用的radius的值。
        if (defaultRadius == leftTopRadius) {
            leftTopRadius = radius;
        }
        if (defaultRadius == rightTopRadius) {
            rightTopRadius = radius;
        }
        if (defaultRadius == rightBottomRadius) {
            rightBottomRadius = radius;
        }
        if (defaultRadius == leftBottomRadius) {
            leftBottomRadius = radius;
        }
        array.recycle();
    }


    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);
        width = getWidth();
        height = getHeight();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        //這裡做下判斷，只有圖片的寬高大於設定的圓角距離的時候才進行裁剪
        int maxLeft = Math.max(leftTopRadius, leftBottomRadius);
        int maxRight = Math.max(rightTopRadius, rightBottomRadius);
        int minWidth = maxLeft + maxRight;
        int maxTop = Math.max(leftTopRadius, rightTopRadius);
        int maxBottom = Math.max(leftBottomRadius, rightBottomRadius);
        int minHeight = maxTop + maxBottom;
        if (width >= minWidth && height > minHeight) {
            Path path = new Path();
            //四個角：右上，右下，左下，左上
            path.moveTo(leftTopRadius, 0);
            path.lineTo(width - rightTopRadius, 0);
            path.quadTo(width, 0, width, rightTopRadius);

            path.lineTo(width, height - rightBottomRadius);
            path.quadTo(width, height, width - rightBottomRadius, height);

            path.lineTo(leftBottomRadius, height);
            path.quadTo(0, height, 0, height - leftBottomRadius);

            path.lineTo(0, leftTopRadius);
            path.quadTo(0, 0, leftTopRadius, 0);

            canvas.clipPath(path);
        }
        super.onDraw(canvas);
    }

}
 

3.佈局檔案中使用

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="voicedemo.iflytek.com.roundimage.MainActivity">

    <voicedemo.iflytek.com.roundimage.RoundCornerImageView
        android:id="@+id/iv_avatar"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_marginBottom="10dp"
        android:layout_marginTop="50dp"
        android:scaleType="centerCrop"
        app:left_top_radius="20dp"
        app:right_top_radius="20dp"
        />


</LinearLayout>
 

4.呼叫

public class MainActivity extends AppCompatActivity {

    String avatarUrl = "https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1516644385815&di=c0552674db9f07a5f889d7c0980e33db&imgtype=0&src=http%3A%2F%2Fimg.mp.itc.cn%2Fupload%2F20170529%2F83d3ce719e9d4c0a8f1cd033ecac3692_th.jpg";

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

        ImageView ivAvatar = findViewById(R.id.iv_avatar);

        Glide.with(this).load(avatarUrl).into(ivAvatar);

    }
}