自定义View圆角边框

public class ImageViewPlus extends ImageView{

  /**

   * android.widget.ImageView

   */

  public static final int TYPE_NONE = 0;

  /**

   * 圆形

   */

  public static final int TYPE_CIRCLE = 1;

  /**

   * 圆角矩形

   */

  public static final int TYPE_ROUNDED_RECT = 2; 

   

  private static final int DEFAULT_TYPE = TYPE_NONE;

  private static final int DEFAULT_BORDER_COLOR = Color.TRANSPARENT;

  private static final int DEFAULT_BORDER_WIDTH = 0;

  private static final int DEFAULT_RECT_ROUND_RADIUS = 0;

   

  private int mType;

  private int mBorderColor;

  private int mBorderWidth;

  private int mRectRoundRadius;

   

  private Paint mPaintBitmap = new Paint(Paint.ANTI_ALIAS_FLAG);

  private Paint mPaintBorder = new Paint(Paint.ANTI_ALIAS_FLAG);

   

  private RectF mRectBorder = new RectF();

  private RectF mRectBitmap = new RectF();

   

  private Bitmap mRawBitmap;

  private BitmapShader mShader;

  private Matrix mMatrix = new Matrix();

   

  public ImageViewPlus(Context context, AttributeSet attrs) {

    super(context, attrs);

    //取xml文件中设定的参数

    TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.ImageViewPlus);

    mType = ta.getInt(R.styleable.ImageViewPlus_type, DEFAULT_TYPE);

    mBorderColor = ta.getColor(R.styleable.ImageViewPlus_borderColor, DEFAULT_BORDER_COLOR);

    mBorderWidth = ta.getDimensionPixelSize(R.styleable.ImageViewPlus_borderWidth, dip2px(DEFAULT_BORDER_WIDTH));

    mRectRoundRadius = ta.getDimensionPixelSize(R.styleable.ImageViewPlus_rectRoundRadius, dip2px(DEFAULT_RECT_ROUND_RADIUS));

    ta.recycle();

  }

   

  @Override

  protected void onDraw(Canvas canvas) {

    Bitmap rawBitmap = getBitmap(getDrawable());

     

    if (rawBitmap != null && mType != TYPE_NONE){

      int viewWidth = getWidth();

      int viewHeight = getHeight();

      int viewMinSize = Math.min(viewWidth, viewHeight);

      float dstWidth = mType == TYPE_CIRCLE ? viewMinSize : viewWidth;

      float dstHeight = mType == TYPE_CIRCLE ? viewMinSize : viewHeight;

      float halfBorderWidth = mBorderWidth / 2.0f;

      float doubleBorderWidth = mBorderWidth * 2;

       

      if (mShader == null || !rawBitmap.equals(mRawBitmap)){

        mRawBitmap = rawBitmap;

        mShader = new BitmapShader(mRawBitmap, TileMode.CLAMP, TileMode.CLAMP);

      }

      if (mShader != null){

        mMatrix.setScale((dstWidth - doubleBorderWidth) / rawBitmap.getWidth(), (dstHeight - doubleBorderWidth) / rawBitmap.getHeight());

        mShader.setLocalMatrix(mMatrix);

      }

       

      mPaintBitmap.setShader(mShader);

      mPaintBorder.setStyle(Paint.Style.STROKE);

      mPaintBorder.setStrokeWidth(mBorderWidth);

      mPaintBorder.setColor(mBorderWidth > 0 ? mBorderColor : Color.TRANSPARENT);

       

      if (mType == TYPE_CIRCLE){

        float radius = viewMinSize / 2.0f;

        canvas.drawCircle(radius, radius, radius - halfBorderWidth, mPaintBorder);

        canvas.translate(mBorderWidth, mBorderWidth);

        canvas.drawCircle(radius - mBorderWidth, radius - mBorderWidth, radius - mBorderWidth, mPaintBitmap);

      } else if (mType == TYPE_ROUNDED_RECT){

        mRectBorder.set(halfBorderWidth, halfBorderWidth, dstWidth - halfBorderWidth, dstHeight - halfBorderWidth);

        mRectBitmap.set(0.0f, 0.0f, dstWidth - doubleBorderWidth, dstHeight - doubleBorderWidth);

        float borderRadius = mRectRoundRadius - halfBorderWidth > 0.0f ? mRectRoundRadius - halfBorderWidth : 0.0f;

        float bitmapRadius = mRectRoundRadius - mBorderWidth > 0.0f ? mRectRoundRadius - mBorderWidth : 0.0f;

        canvas.drawRoundRect(mRectBorder, borderRadius, borderRadius, mPaintBorder);

        canvas.translate(mBorderWidth, mBorderWidth);

        canvas.drawRoundRect(mRectBitmap, bitmapRadius, bitmapRadius, mPaintBitmap);

      }

    } else {

      super.onDraw(canvas);

    }

  }

 

  private int dip2px(int dipVal)

  {

    float scale = getResources().getDisplayMetrics().density;

    return (int)(dipVal * scale + 0.5f);

  }

   

  private Bitmap getBitmap(Drawable drawable){

    if (drawable instanceof BitmapDrawable){

      return ((BitmapDrawable)drawable).getBitmap();

    } else if (drawable instanceof ColorDrawable){

      Rect rect = drawable.getBounds();

      int width = rect.right - rect.left;

      int height = rect.bottom - rect.top;

      int color = ((ColorDrawable)drawable).getColor();

      Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);

      Canvas canvas = new Canvas(bitmap);

      canvas.drawARGB(Color.alpha(color), Color.red(color), Color.green(color), Color.blue(color));

      return bitmap;

    } else {

      return null;

    }

  }

}

在Values里创建一个attrs.xml

<? xml version = "1.0" encoding = "utf-8" ?>

< resources >

   < attr name = "type" >

     < enum name = "none" value = "0" />

     < enum name = "circle" value = "1" />

     < enum name = "rounded_rect" value = "2" />

   </ attr >

   < attr name = "borderColor" format = "color" />

   < attr name = "borderWidth" format = "dimension" />

   < attr name = "rectRoundRadius" format = "dimension" />

 

   < declare-styleable name = "ImageViewPlus" >

     < attr name = "type" />

     < attr name = "borderColor" />

     < attr name = "borderWidth" />

     < attr name = "rectRoundRadius" />

   </ declare-styleable >

</ resources >

最后在布局里引用就可以了

<cc.snser.imageviewplus.ImageViewPlus

     android:id = "@+id/imgplus"

     android:layout_width = "200dp"

     android:layout_height = "300dp"

     android:layout_marginBottom = "50dp"

     android:layout_centerHorizontal = "true"

     android:layout_alignParentBottom = "true"

     android:src = "@drawable/img_rectangle"

     snser:type = "rounded_rect"

     snser:borderColor = "#FF0080FF"

     snser:borderWidth = "10dp"

     snser:rectRoundRadius = "30dp" />