Android实现图片设置圆角形式

本文实例为大家分享了Android实现图片设置圆角形式的具体代码，供大家参考，具体内容如下

1.自定义的图片圆角形式CircleImageView类

public class CircleImageView extends ImageView {
   private static final Xfermode MASK_XFERMODE;
   private Bitmap mask;
   private Paint paint;
   private int mBorderWidth = 10;
   private int mBorderColor = Color.parseColor("#f2f2f2");
   private boolean useDefaultStyle = false;

static {
       PorterDuff.Mode localMode = PorterDuff.Mode.DST_IN;
       MASK_XFERMODE = new PorterDuffXfermode(localMode);
   }

public CircleImageView(Context context) {
       super(context);
   }

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

public CircleImageView(Context context, AttributeSet attrs, int defStyle) {
       super(context, attrs, defStyle);
       TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CircularImage);
       mBorderColor = a.getColor(R.styleable.CircularImage_border_color, mBorderColor);
       final int def = (int) (2 * context.getResources().getDisplayMetrics().density + 0.5f);
       mBorderWidth = a.getDimensionPixelOffset(R.styleable.CircularImage_border_width, def);
       a.recycle();
   }

private void useDefaultStyle(boolean useDefaultStyle) {
       this.useDefaultStyle = useDefaultStyle;
   }

@Override
   protected void onDraw(Canvas canvas) {
       if (useDefaultStyle) {
           super.onDraw(canvas);
           return;
       }
       final Drawable localDraw = getDrawable();
       if (localDraw == null) {
           return;
       }
       if (localDraw instanceof NinePatchDrawable) {
           return;
       }
       if (this.paint == null) {
           final Paint localPaint = new Paint();
           localPaint.setFilterBitmap(false);
           localPaint.setAntiAlias(true);
           localPaint.setXfermode(MASK_XFERMODE);
           this.paint = localPaint;
       }
       final int width = getWidth();
       final int height = getHeight();
       /** 保存layer */
       int layer = canvas.saveLayer(0.0F, 0.0F, width, height, null, 31);
       /** 设置drawable的大小 */
       localDraw.setBounds(0, 0, width, height);
       /** 将drawable绑定到bitmap(this.mask)上面（drawable只能通过bitmap显示出来） */
       localDraw.draw(canvas);
       if ((this.mask == null) || (this.mask.isRecycled())) {
           this.mask = createOvalBitmap(width, height);
       }
       /** 将bitmap画到canvas上面 */
       canvas.drawBitmap(this.mask, 0.0F, 0.0F, this.paint);
       /** 将画布复制到layer上 */
       canvas.restoreToCount(layer);
       drawBorder(canvas, width, height);
   }

/**
    * 绘制圆形边框
    */
   private void drawBorder(Canvas canvas, final int width, final int height) {
       if (mBorderWidth == 0) {
           return;
       }
       final Paint mBorderPaint = new Paint();
       mBorderPaint.setStyle(Paint.Style.STROKE);
       mBorderPaint.setAntiAlias(true);
       mBorderPaint.setColor(mBorderColor);
       mBorderPaint.setStrokeWidth(mBorderWidth);
       canvas.drawCircle(width / 2, height / 2, (width - mBorderWidth) / 2, mBorderPaint);
       canvas = null;
   }

public Bitmap createOvalBitmap(final int width, final int height) {
       Bitmap.Config localConfig = Bitmap.Config.ARGB_8888;
       Bitmap localBitmap = Bitmap.createBitmap(width, height, localConfig);
       Canvas localCanvas = new Canvas(localBitmap);
       Paint localPaint = new Paint();
       final int padding = (mBorderWidth - 3) > 0 ? mBorderWidth - 3 : 1;
       /**
        * 设置椭圆的大小(因为椭圆的最外边会和border的最外边重合的，如果图片最外边的颜色很深，有看出有棱边的效果，所以为了让体验更加好，
        * 让其缩进padding px)
        */
       RectF localRectF = new RectF(padding, padding, width - padding, height - padding);
       localCanvas.drawOval(localRectF, localPaint);
       return localBitmap;
   }
}

1.1 在values目录下创建一个circle_attr.xml，文件内容：

<?xml version="1.0" encoding="utf-8"?>
<resources>
   <declare-styleable name="CircularImage">
       <attr name="border_width" format="dimension" />
       <attr name="border_color" format="color" />
   </declare-styleable>
</resources>

如下图：

2.activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:orientation="vertical">

<LinearLayout
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:orientation="horizontal">

<ImageView
           android:layout_width="100dp"
           android:layout_height="100dp"
           android:src="@drawable/ic_sp" />

<com.demo.test.bitmap.CircleImageView
           android:layout_width="100dp"
           android:layout_height="100dp"
           android:layout_marginLeft="50dp"
           android:src="@drawable/ic_sp" />
   </LinearLayout>
</LinearLayout>

3.MainActivity.java

public class MainActivity extends AppCompatActivity {

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

运行后结果：

来源：https://blog.csdn.net/qq_35091074/article/details/121517918