Android自定义Drawable实现圆形和圆角

本文实例为大家分享了自定义Drawable实现圆形和圆角的具体代码，供大家参考，具体内容如下

圆形

package com.customview.widget;

import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.ColorFilter;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.graphics.Shader;
import android.graphics.drawable.Drawable;
import android.support.annotation.IntRange;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;

/**
* 自定义Drawable 实现圆形图片
* Created by hust_twj on 2017/9/26.
*/

public class CircleDrawable extends Drawable {
 private Paint mPaint;
 private int mWidth; //宽/高，直径
 private Bitmap mBitmap;

public CircleDrawable(Bitmap bitmap) {
   this.mBitmap = bitmap;
   BitmapShader bitmapShader = new BitmapShader(mBitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);//着色器 水平和竖直都需要填充满
   mPaint = new Paint();
   mPaint.setAntiAlias(true);
   mPaint.setShader(bitmapShader);
   mWidth = Math.min(mBitmap.getWidth(), mBitmap.getHeight()); //宽高的最小值作为直径
 }

@Override
 public void draw(@NonNull Canvas canvas) {
   canvas.drawCircle(mWidth/2, mWidth/2, mWidth/2, mPaint); //绘制圆形
 }

@Override
 public void setAlpha(@IntRange(from = 0, to = 255) int i) {
   mPaint.setAlpha(i);
 }

@Override
 public void setColorFilter(@Nullable ColorFilter colorFilter) {
   mPaint.setColorFilter(colorFilter);
 }

@Override
 public int getOpacity() {
   return PixelFormat.TRANSLUCENT; //设置系统默认，让drawable支持和窗口一样的透明度
 }

//还需要从重写以下2个方法，返回drawable实际宽高
 @Override
 public int getIntrinsicWidth() {
   return mWidth;
 }

@Override
 public int getIntrinsicHeight() {
   return mWidth;
 }

}

圆角：

package com.customview.widget;

import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.ColorFilter;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.graphics.RectF;
import android.graphics.Shader;
import android.graphics.drawable.Drawable;
import android.support.annotation.IntRange;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;

/**
* 自定义Drawable 实现圆角图片
* Created by hust_twj on 2017/9/26.
*/

public class RoundCornerDrawable extends Drawable {
 private Paint mPaint;
 private RectF rectF;//定义矩形区域
 private Bitmap mBitmap;

public RoundCornerDrawable(Bitmap bitmap) {
   this.mBitmap = bitmap;
   BitmapShader bitmapShader = new BitmapShader(mBitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);//着色器 水平和竖直都需要填充满
   mPaint = new Paint();
   mPaint.setAntiAlias(true);
   mPaint.setShader(bitmapShader);
   //rectF = new RectF(0, 0, bitmap.getWidth(), bitmap.getHeight());
 }

@Override
 public void draw(@NonNull Canvas canvas) {
   //RectF:圆角矩形区域
   canvas.drawRoundRect(new RectF(0, 0, mBitmap.getWidth(), mBitmap.getHeight()),100, 100, mPaint);//rx：x方向上的圆角半径; ry：y方向上的圆角半径。
 }

/*  @Override
 public void setBounds(int left, int top, int right, int bottom) {
   super.setBounds(left, top, right, bottom);
   rectF = new RectF(left, top, right, bottom);
 }*/

@Override
 public void setAlpha(@IntRange(from = 0, to = 255) int i) {
   mPaint.setAlpha(i);
 }

@Override
 public void setColorFilter(@Nullable ColorFilter colorFilter) {
   mPaint.setColorFilter(colorFilter);
 }

@Override
 public int getOpacity() {
   return PixelFormat.TRANSLUCENT; //设置系统默认，让drawable支持和窗口一样的透明度
 }

//还需要从重写以下2个方法，返回drawable实际宽高
 @Override
 public int getIntrinsicWidth() {
   return mBitmap.getWidth();
 }

@Override
 public int getIntrinsicHeight() {
   return mBitmap.getHeight();
 }

}

MainActivity中：

Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.XXX);
imageView.setImageDrawable(new RoundCornerDrawable(bitmap));

来源：http://blog.csdn.net/hust_twj/article/details/78109730