自定义imageview 实现圆角 甚至圆形imageview（并不是将图片变圆角）

最近遇到新需求 不论用户上传什么形状的头像 展示的时候都要显示成圆形 且头像背后是有背景图的 。

于是想到了 将控件变圆 这样可以任意适配了

先上效果图

下图为方形头像





而此处展示为圆形





下面展示下 重写的imageview 实质是用canvas去画控件的四个角

[java] view
plaincopy





/*

* 文 件 名: MyImageView.java

* 版 权: Linkage Technology Co., Ltd. Copyright 2010-2011, All rights reserved

* 描 述: <描述>

* 版 本： <版本号>

* 创 建 人: Wuhq

* 创建时间: 2013-12-11

*/

package com.suo.myimage;

import android.content.Context;

import android.content.res.TypedArray;

import android.graphics.Bitmap;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.graphics.Path;

import android.graphics.PorterDuff;

import android.graphics.PorterDuffXfermode;

import android.graphics.RectF;

import android.graphics.Bitmap.Config;

import android.util.AttributeSet;

import android.widget.ImageView;

/**

* <一句话功能简述>

* <功能详细描述>

*

* @author Wuhq

* @version [版本号, 2013-12-11]

* @see [相关类/方法]

* @since [产品/模块版本]

*/

public class MyImageView extends ImageView

{

private Paint paint;

private int roundWidth = 180; //这里的宽高很关键

private int roundHeight = 180; //这里的宽高很关键

private Paint paint2;

public MyImageView(Context context, AttributeSet attrs, int defStyle) {

super(context, attrs, defStyle);

init(context, attrs);

}

public MyImageView(Context context, AttributeSet attrs) {

super(context, attrs);

init(context, attrs);

}

public MyImageView(Context context) {

super(context);

init(context, null);

}

private void init(Context context, AttributeSet attrs) {

if(attrs != null) {

TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.RoundAngleImageView);

roundWidth= a.getDimensionPixelSize(R.styleable.RoundAngleImageView_roundWidth, roundWidth);

roundHeight= a.getDimensionPixelSize(R.styleable.RoundAngleImageView_roundHeight, roundHeight);

}else {

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

roundWidth = (int) (roundWidth*density);

roundHeight = (int) (roundHeight*density);

}

paint = new Paint();

paint.setColor(Color.WHITE);

paint.setAntiAlias(true);

paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));

paint2 = new Paint();

paint2.setXfermode(null);

}

@Override

public void draw(Canvas canvas) {

Bitmap bitmap = Bitmap.createBitmap(getWidth(), getHeight(), Config.ARGB_8888);

Canvas canvas2 = new Canvas(bitmap);

super.draw(canvas2);

drawLiftUp(canvas2);

drawRightUp(canvas2);

drawLiftDown(canvas2);

drawRightDown(canvas2);

canvas.drawBitmap(bitmap, 0, 0, paint2);

bitmap.recycle();

}

private void drawLiftUp(Canvas canvas) {

Path path = new Path();

path.moveTo(0, roundHeight);

path.lineTo(0, 0);

path.lineTo(roundWidth, 0);

path.arcTo(new RectF(

0,

0,

roundWidth*2,

roundHeight*2),

-90,

-90);

path.close();

canvas.drawPath(path, paint);

}

private void drawLiftDown(Canvas canvas) {

Path path = new Path();

path.moveTo(0, getHeight()-roundHeight);

path.lineTo(0, getHeight());

path.lineTo(roundWidth, getHeight());

path.arcTo(new RectF(

0,

getHeight()-roundHeight*2,

0+roundWidth*2,

getHeight()),

90,

90);

path.close();

canvas.drawPath(path, paint);

}

private void drawRightDown(Canvas canvas) {

Path path = new Path();

path.moveTo(getWidth()-roundWidth, getHeight());

path.lineTo(getWidth(), getHeight());

path.lineTo(getWidth(), getHeight()-roundHeight);

path.arcTo(new RectF(

getWidth()-roundWidth*2,

getHeight()-roundHeight*2,

getWidth(),

getHeight()), 0, 90);

path.close();

canvas.drawPath(path, paint);

}

private void drawRightUp(Canvas canvas) {

Path path = new Path();

path.moveTo(getWidth(), roundHeight);

path.lineTo(getWidth(), 0);

path.lineTo(getWidth()-roundWidth, 0);

path.arcTo(new RectF(

getWidth()-roundWidth*2,

0,

getWidth(),

0+roundHeight*2),

-90,

90);

path.close();

canvas.drawPath(path, paint);

}

}

这是类文件 注意我将控件宽高置为了屏幕宽度的一半 由于我机型分辨率是1280*720 所以一半便是360 所以在上面的自定义imageview里宽高再取一半便是180 这也就是变成圆形的关键 你们可以动态去获取 我就偷懒写死了。

[java] view
plaincopy





package com.suo.myimage;

import android.os.Bundle;

import android.app.Activity;

import android.content.Context;

import android.view.Menu;

import android.view.WindowManager;

import android.widget.ImageView;

import android.widget.LinearLayout;

import android.widget.RelativeLayout;

public class MainActivity extends Activity {

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

MyImageView image = (MyImageView) findViewById(R.id.image);

WindowManager wm = (WindowManager)getSystemService(Context.WINDOW_SERVICE);

[java] view
plaincopy





int width = wm.getDefaultDisplay().getWidth()/2;//这里我将控件宽高设为屏幕一半 正方形

int height = width;

//更改该imageview的宽高并重构实现圆角

RelativeLayout.LayoutParams linearParams =(RelativeLayout.LayoutParams) image.getLayoutParams();

linearParams.width = width;

linearParams.height = height;

image.invalidate();

}

}

最后是布局文件

[java] view
plaincopy





<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

tools:context=".MainActivity"

android:background="@drawable/aa" >

<com.suo.myimage.MyImageView

android:id="@+id/image"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:src="@drawable/bb"

android:layout_margin="5dp"/>

</RelativeLayout>