100行代码 CircleImageView

IDE预览效果

手机截屏

100行代码实现圆形ImageView

package com.example.androidtest;import android.content.Context;import android.graphics.Bitmap;import android.graphics.Canvas;import android.graphics.Paint;import android.graphics.PorterDuff.Mode;import android.graphics.PorterDuffXfermode;import android.graphics.drawable.BitmapDrawable;import android.graphics.drawable.ColorDrawable;import android.graphics.drawable.Drawable;import android.graphics.Bitmap.Config;import android.util.AttributeSet;import android.widget.ImageView;public class CircleView extends ImageView {public CircleView(Context context) {super(context);}public CircleView(Context context, AttributeSet attrs) {super(context, attrs);}public CircleView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);}/** * 布局预览时会调用该方法 */@Overridepublic void setImageDrawable(Drawable drawable) {Bitmap bitmap1 = getBitmapFromDrawable(drawable);//获取到Bitmap//创建同样大小的Bitmap作为画布Bitmap bitmap2 = Bitmap.createBitmap(bitmap1.getWidth(), bitmap1.getHeight(), Config.ARGB_8888);//画在bitmap2上Canvas canvas = new Canvas(bitmap2);Paint paint = new Paint();paint.setAntiAlias(true);//找到短的边作为圆的直径int r;if (bitmap2.getHeight() > bitmap2.getWidth()) {r = bitmap2.getWidth() / 2;} else {r = bitmap2.getHeight() / 2;}//在bitmap2上画圆canvas.drawCircle(bitmap2.getWidth() / 2, bitmap2.getHeight() / 2, r, paint);//设置为SRC_IN，即显示重叠部分中后画的部分。   先画的部分为DST，后画的为SRCpaint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));//把原来的bitmap1画到bitmap2上canvas.drawBitmap(bitmap1, 0, 0, paint);//上面执行完毕后bitmap2就是所要的圆形图片了super.setImageDrawable(new BitmapDrawable(bitmap2));}@Overridepublic void setImageResource(int resId) {setImageDrawable(getResources().getDrawable(resId));}/** * 获取Drawable对应的Bitmap * @param drawable * @return */private Bitmap getBitmapFromDrawable(Drawable drawable) {if (drawable == null) {return null;}if (drawable instanceof BitmapDrawable) {return ((BitmapDrawable) drawable).getBitmap();}try {Bitmap bitmap;if (drawable instanceof ColorDrawable) {bitmap = Bitmap.createBitmap(1, 1, Config.ARGB_8888);} else {bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(),Config.ARGB_8888);}Canvas canvas = new Canvas(bitmap);drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());drawable.draw(canvas);return bitmap;} catch (OutOfMemoryError e) {return null;}}}

布局

<ScrollView 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" >    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:background="#888"        android:orientation="vertical" >                        <com.example.androidtest.CircleView            android:id="@+id/civ"            android:scaleType="centerCrop"            android:layout_width="100dp"            android:layout_height="100dp"            android:src="@drawable/pic"           />        <ImageView            android:layout_marginTop="10dp"            android:layout_width="100dp"            android:layout_height="100dp"                        android:scaleType="centerCrop"            android:background="#080"            android:src="@drawable/pic" />                                        <com.example.androidtest.CircleView            android:id="@+id/civ2"            android:scaleType="centerCrop"            android:layout_width="100dp"            android:layout_height="100dp"            android:src="@drawable/iii"              />        <ImageView            android:layout_marginTop="10dp"            android:layout_width="100dp"            android:layout_height="100dp"                        android:scaleType="centerCrop"            android:background="#080"            android:src="@drawable/iii" />                  <com.example.androidtest.CircleView            android:id="@+id/civ3"            android:scaleType="centerCrop"            android:layout_width="100dp"            android:layout_height="100dp"            android:src="@drawable/pic"              />        <ImageView            android:layout_marginTop="10dp"            android:layout_width="100dp"            android:layout_height="100dp"                        android:scaleType="centerCrop"            android:background="#080"            android:src="@drawable/pic" />    </LinearLayout></ScrollView>

调用

package com.example.androidtest;import android.os.Bundle;import android.app.Activity;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Canvas;import android.graphics.Paint;import android.graphics.PorterDuffXfermode;import android.graphics.Bitmap.Config;import android.graphics.PorterDuff.Mode;import android.view.Menu;public class MainActivity extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);                CircleView civ=(CircleView) findViewById(R.id.civ);        Bitmap bitmap1=BitmapFactory.decodeResource(getResources(), R.drawable.pic);        civ.setImageBitmap(bitmap1);                        CircleView civ2=(CircleView) findViewById(R.id.civ2);        civ2.setImageResource(R.drawable.iii);                        CircleView civ3=(CircleView) findViewById(R.id.civ3);        civ3.setImageDrawable(getResources().getDrawable(R.drawable.iii));;                    }   }