圆角矩形图片在苹果的产品中很流行,相比于普通的矩形,很多人都喜欢圆角矩形的图片,因为它避开了直角的生硬,带来更好的用户体验,下面是几个设计的例子:
下面在Android中实现将普通的矩形图片绘制成圆角矩形。首先看最终效果:
package com.example.phototest; import android.os.Bundle; import android.app.Activity; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.Path; import android.graphics.PorterDuffXfermode; import android.graphics.PorterDuff; import android.graphics.RectF; import android.graphics.drawable.BitmapDrawable; import android.graphics.drawable.Drawable; import android.view.Menu; import android.widget.ImageView; public class MainActivity extends Activity { private ImageView myImageView; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); myImageView=(ImageView)findViewById(R.id.imageView1); Bitmap photo = BitmapFactory.decodeResource(getResources(), R.drawable.photo1); myImageView.setImageBitmap(createFramedPhoto(500,400,photo,20)); //myImageView.setImageBitmap(createStarPhoto(500,400,photo)); } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.activity_main, menu); return true; } private Bitmap createFramedPhoto(int x, int y, Bitmap image, float outerRadiusRat) { //根据源文件新建一个darwable对象 Drawable imageDrawable = new BitmapDrawable(image); // 新建一个新的输出图片 Bitmap output = Bitmap.createBitmap(x, y, Bitmap.Config.ARGB_8888); Canvas canvas = new Canvas(output); // 新建一个矩形 RectF outerRect = new RectF(0, 0, x, y); // 产生一个红色的圆角矩形 Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG); paint.setColor(Color.RED); canvas.drawRoundRect(outerRect, outerRadiusRat, outerRadiusRat, paint); // 将源图片绘制到这个圆角矩形上 //详解见http://lipeng88213.iteye.com/blog/1189452 paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN)); imageDrawable.setBounds(0, 0, x, y); canvas.saveLayer(outerRect, paint, Canvas.ALL_SAVE_FLAG); imageDrawable.draw(canvas); canvas.restore(); return output; } }
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
代码:
private Bitmap createStarPhoto(int x, int y, Bitmap image) { //根据源文件新建一个darwable对象 Drawable imageDrawable = new BitmapDrawable(image); // 新建一个新的输出图片 Bitmap output = Bitmap.createBitmap(x, y, Bitmap.Config.ARGB_8888); Canvas canvas = new Canvas(output); // 新建一个矩形 RectF outerRect = new RectF(0, 0, x, y); Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG); paint.setColor(Color.RED); Path path = new Path(); //绘制三角形 //path.moveTo(0, 0); //path.lineTo(320, 250); //path.lineTo(400, 0); //绘制正无边形 long tmpX,tmpY; path.moveTo(200, 200);// 此点为多边形的起点 for(int i=0;i<=5;i++) { tmpX =(long)(200+200*Math.sin((i*72+36)*2*Math.PI/360)); tmpY =(long)(200+200*Math.cos((i*72+36)*2*Math.PI/360)); path.lineTo(tmpX, tmpY); } path.close(); // 使这些点构成封闭的多边形 canvas.drawPath(path, paint); //canvas.drawCircle(100, 100, 100, paint); // 将源图片绘制到这个圆角矩形上 // 产生一个红色的圆角矩形 paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN)); imageDrawable.setBounds(0, 0, x, y); canvas.saveLayer(outerRect, paint, Canvas.ALL_SAVE_FLAG); imageDrawable.draw(canvas); canvas.restore(); return output; }