Android开发使用Drawable绘制圆角与圆形图案功能示例

本文实例讲述了Android开发使用Drawable绘制圆角与圆形图案功能。分享给大家供大家参考，具体如下：

1. 创建类RoundCircleDrawable继承Drawable

/**
* 圆角矩形
* @Project  App_View
* @Package  com.android.view.drawable
* @author   chenlin
* @version  1.0
* @Date    2016年4月21日
* @Note    TODO
*/
public class RoundCircleDrawable extends Drawable{
 private Paint mPaint;//画笔
 private int mWidth;//图片宽与长度的最小值
 private int mRadius;//半径
 private int mRound;//圆角
 private RectF mRectF;//矩形
 private Bitmap mBitmap;//图片
 private Type mType = Type.TYPE_ROUND;//默认是矩形
 //设置类型
 enum Type{
   TYPE_ROUND, TYPE_CICLE;
 }
 public RoundCircleDrawable(Bitmap bitmap){
   this.mBitmap = bitmap;
   //初始化画笔
   mPaint = new Paint();
   mPaint.setAntiAlias(true);
   BitmapShader shader = new BitmapShader(mBitmap, TileMode.CLAMP, TileMode.CLAMP);
   mPaint.setShader(shader);
   mWidth = Math.min(mBitmap.getWidth(), mBitmap.getHeight());
   mRadius = mWidth / 2;
 }
 /**
  * 向外提供设置图片类型的方法
  * @param type
  */
 public void setType(Type type){
   this.mType = type;
 }
 /**
  * 暴露给外面设置圆角的大小
  *
  * @param round
  */
 public void setRound(int round) {
   this.mRound = round;
 }
 @Override
 public void setBounds(int left, int top, int right, int bottom) {
   super.setBounds(left, top, right, bottom);
   mRectF = new RectF(left, top, right, bottom);
 }
 @Override
 public void draw(Canvas canvas) {
   if (mType == Type.TYPE_ROUND) {
     canvas.drawRoundRect(mRectF, mRound, mRound, mPaint);
   }else {
     canvas.drawCircle(mWidth / 2, mWidth / 2, mRadius, mPaint);
   }
 }
 @Override
 public int getIntrinsicWidth() {
   if (mType == Type.TYPE_CICLE) {
     return mWidth;
   }else {
     return mBitmap.getWidth();
   }
 }
 @Override
 public int getIntrinsicHeight() {
   if (mType == Type.TYPE_CICLE) {
     return mWidth;
   }else {
     return mBitmap.getHeight();
   }
 }
 @Override
 public void setAlpha(int alpha) {
   mPaint.setAlpha(alpha);
 }
 @Override
 public void setColorFilter(ColorFilter cf) {
   mPaint.setColorFilter(cf);
 }
 @Override
 public int getOpacity() {
   return PixelFormat.TRANSLUCENT;
 }
}

2. 实现方法

public class RoundActivity extends Activity {
 private ImageView mImageView;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);
   setContentView(R.layout.activity_round_drawable);
   mImageView = (ImageView) findViewById(R.id.iv_round);
   Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.aa);
   //RoundImageDrawable drawable = new RoundImageDrawable(bitmap);
   //drawable.setRound(30);
   RoundCircleDrawable drawable = new RoundCircleDrawable(bitmap);
   drawable.setRound(50);
   mImageView.setImageDrawable(drawable);
 }
}

希望本文所述对大家Android程序设计有所帮助。

来源：http://blog.csdn.net/lovoo/article/details/51207527