Android圆角图片

自定义ImageView

package com.interjoy.testdemo.views;import android.content.Context;import android.graphics.Bitmap;import android.graphics.Bitmap.Config;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.util.AttributeSet;import android.util.Log;import android.widget.ImageView;import java.text.SimpleDateFormat;import java.util.Date;/** * 主要有两种方式实现，Xfermode方式和bitmapShader方式 * Xfermode * * @author ylwang */public class RoundCornerImageView extends ImageView {    private Paint mPaint;    private Paint mPaint2;    private int roundHeight = 300;    private int roundWidth = 300;    private SimpleDateFormat simpleDateFormat;    public RoundCornerImageView(Context context, AttributeSet attrs,                                int defStyle) {        super(context, attrs, defStyle);    }    public RoundCornerImageView(Context context, AttributeSet attrs) {        super(context, attrs);        init();    }    public RoundCornerImageView(Context context) {        super(context);        init();    }    private void init() {        mPaint = new Paint();        mPaint.setColor(Color.WHITE);        mPaint.setAntiAlias(true);        //16种状态        mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));        mPaint2 = new Paint();        mPaint2.setXfermode(null);        simpleDateFormat = new SimpleDateFormat("'[秒:毫秒] 'ss:SSS");    }    int i = 0;    @Override    public void onDraw(Canvas canvas) {        String time = simpleDateFormat.format(new Date());        int width = getWidth();        Log.d("&&&&", "onDraw 执行次数 = " + (++i) + ",  width = " + width + ",  执行时刻->" + time);        if (width == 0) {            super.onDraw(canvas);            return;        }        Bitmap bitmap = Bitmap.createBitmap(getWidth(), getHeight(), Config.ARGB_8888);        Canvas canvas2 = new Canvas(bitmap);        super.onDraw(canvas2);        drawLeftUp(canvas2);        drawRightUp(canvas2);        drawLeftDown(canvas2);        drawRightDown(canvas2);        canvas.drawBitmap(bitmap, 0, 0, mPaint2);        bitmap.recycle();    }    private void drawLeftUp(Canvas canvas) {        Path path = new Path();        path.moveTo(0, roundHeight);        path.lineTo(0, 0);        path.lineTo(roundWidth, 0);        //arcTo的第二个参数是以多少度为开始点，第三个参数-90度表示逆时针画弧，正数表示顺时针        path.arcTo(new RectF(0, 0, roundWidth * 2, roundHeight * 2), -90, -90);        path.close();        canvas.drawPath(path, mPaint);    }    private void drawLeftDown(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, mPaint);    }    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, mPaint);    }    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, mPaint);    }}

布局文件

<?xml version="1.0" encoding="utf-8"?><LinearLayout 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"    android:orientation="vertical"    tools:context="com.interjoy.testdemo.Activities.ClipActivity">    <com.interjoy.testdemo.views.RoundCornerImageView        android:layout_margin="20dp"        android:src="@drawable/yy6"        android:id="@+id/iv_clip"        android:layout_width="200dp"        android:layout_height="200dp" />    <Button        android:id="@+id/btn_show_image"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="显示另外一张图片" /></LinearLayout>

Activity调用

package com.interjoy.testdemo.Activities;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.view.ViewGroup;import android.widget.ImageView;import com.interjoy.testdemo.R;import com.interjoy.testdemo.views.RoundCornerImageView;public class ClipActivity extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_clip);        initViews();    }    private void initViews() {        final ImageView imageView = new RoundCornerImageView(this);        addContentView(imageView,new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,ViewGroup.LayoutParams.WRAP_CONTENT));        findViewById(R.id.btn_show_image).setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                imageView.setImageResource(R.drawable.yy6);            }        });    }}

运行效果图