Android 图片圆角，自定义圆角的弧度，或者直接设置为圆形图片

1，创建RoundImageView继承自ImageView或者继承AppCompatImageView

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.support.v7.widget.AppCompatImageView;

import com.xhs.sc.R;

/**
 * 圆角ImageView
 *AppCompatImageView
 * @author xhs 2017-7
 */
public class RoundImageView extends AppCompatImageView {
    private final RectF roundRect = new RectF();
    private float rect_adius = 100;
    private final Paint maskPaint = new Paint();
    private final Paint zonePaint = new Paint();

    public RoundImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
        TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.RoundImageView);
        //根据属性名称获取对应的值，属性名称的格式为类名_属性名
        rect_adius = typedArray.getFloat(R.styleable.RoundImageView_rect_adius, 100f);
        init();
    }

    public RoundImageView(Context context) {
        super(context);
        init();
    }

    private void init() {
        maskPaint.setAntiAlias(true);
        maskPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
        //
        zonePaint.setAntiAlias(true);
        zonePaint.setColor(Color.WHITE);
        //
        float density = getResources().getDisplayMetrics().density;
        rect_adius = rect_adius * density;
    }

    public void setRectAdius(float adius) {
        rect_adius = adius;
        invalidate();
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right,
                            int bottom) {
        super.onLayout(changed, left, top, right, bottom);
        int w = getWidth();
        int h = getHeight();
        roundRect.set(0, 0, w, h);
    }

    @Override
    public void draw(Canvas canvas) {
        canvas.saveLayer(roundRect, zonePaint, Canvas.ALL_SAVE_FLAG);
        canvas.drawRoundRect(roundRect, rect_adius, rect_adius, zonePaint);
        //
        canvas.saveLayer(roundRect, maskPaint, Canvas.ALL_SAVE_FLAG);
        super.draw(canvas);
        canvas.restore();
    }
}

2，自定义View的属性，在values下styles.xml中添加

<declare-styleable name="RoundImageView">
    <attr name="rect_adius" format="float" />
</declare-styleable>

3，在布局文件中使用

<com.xhs.sc.views.RoundImageView
    android:id="@+id/item_img"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:scaleType="centerCrop"
    android:src="@mipmap/everyday_sign_item0"
    custom:rect_adius="5" /><!--这里rect_adius就是图片的圆角弧度，100或者更高就是圆形了-->

4，使用时候 ImageView img = (ImageView)findViewById(R.id.item_img);直接转化为ImageView就行，因为本来就是继承自ImageView的；

Android 图片圆角，自定义圆角的弧度，或者直接设置为圆形图片

猜你喜欢