自定义圆形头像

任务内容：需要再主界面中显示截取圆形头像之后的结果，另外有一个界面用于拖动和放置所需要截取的图片。

现在我只完成了一个demo，边界限制等还没有实现，整理一下思路，先把这个demo放过来：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical">    <FrameLayout        android:layout_weight="4"        android:layout_width="match_parent"        android:layout_height="wrap_content">        <ImageView        android:id="@+id/image_to_show"        android:layout_width="wrap_content"        android:layout_height="wrap_content" /></FrameLayout>    <Button        android:id="@+id/start"        android:textSize="25dp"        android:text="没错就是这一张图片了！"        android:layout_gravity="center"        android:layout_width="wrap_content"        android:layout_height="wrap_content" /></LinearLayout>

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical">    <FrameLayout        android:id="@+id/frame_layout"        android:layout_width="wrap_content"        android:layout_height="wrap_content">        <ImageView            android:scaleType="matrix"            android:id="@+id/imageView_ready_to_process"            android:src="@drawable/face6"            android:layout_width="wrap_content"            android:layout_height="wrap_content" />        <ImageView            android:src="@drawable/crop"            android:layout_width="match_parent"            android:layout_height="wrap_content" />    </FrameLayout>    <LinearLayout        android:orientation="horizontal"        android:layout_width="wrap_content"        android:layout_height="wrap_content">  <Button        android:layout_gravity="center"        android:id="@+id/sure_to_crop"        android:text="process"        android:textSize="5dp"        android:layout_width="wrap_content"        android:layout_height="wrap_content" />        <ImageView            android:id="@+id/image_to_test"            android:layout_width="wrap_content"            android:layout_height="wrap_content" />    </LinearLayout></LinearLayout>

这里我用的是FrameLayout 便于连个文件的叠加；crop是我在drawbable中写的一个圆形的遮罩(可以这样理解吧。。)

<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android"    android:shape="oval">    <solid android:color="#00000000"/>    <stroke android:width="3dp"/>    <size android:width="400dp"        android:height="400dp"/></shape>

在这里我设置了它的大小为400dp，其实这样写非常不恰当，我是测试过原图片的（face6）的大小为400dp左右才这么写的

package com.muxi.kolibreath.circleavatardemo;import android.content.Intent;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Canvas;import android.graphics.Paint;import android.graphics.PorterDuff;import android.graphics.PorterDuffXfermode;import android.graphics.RectF;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.util.Log;import android.view.View;import android.widget.Button;import android.widget.FrameLayout;import android.widget.ImageView;public class MainActivity extends AppCompatActivity {    private Button start;    private ImageView imageView_to_show;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        imageView_to_show = (ImageView) findViewById(R.id.image_to_show);        start = (Button) findViewById(R.id.start);        frameLayout = (FrameLayout) findViewById(R.id.frame_layout);        start.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                Intent intent = new Intent(MainActivity.this,EditActivity.class);                startActivityForResult(intent,1);            }        });    }    public Bitmap roundBitmap(Bitmap bitmap){        int width = bitmap.getWidth();        int height = bitmap.getHeight();        int radius = Math.min(width,height);        Bitmap bitmap_for_canvas = Bitmap.createBitmap(radius,radius, Bitmap.Config.ARGB_8888);        Canvas canvas = new Canvas(bitmap_for_canvas);        Paint paint = new Paint();        RectF rectF = new RectF(0,0,radius,radius);        canvas.drawOval(rectF,paint);        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));        paint.setAntiAlias(true);        //0，0表示距离bitmap左右图片的距离        canvas.drawBitmap(bitmap,0,0,paint);        return bitmap_for_canvas;    }    @Override    protected void onActivityResult(int requestCode, int resultCode, Intent data) {        super.onActivityResult(requestCode, resultCode, data);        switch (requestCode){            case 1:                if(resultCode==RESULT_OK){                    byte[] bytes = data.getByteArrayExtra("bitmap");                    Log.d("size",bytes.length + "");                    Bitmap bitmap = BitmapFactory.decodeByteArray(bytes,0,bytes.length);                    imageView_to_show.setImageBitmap(roundBitmap(bitmap));                }                break;        }    }}

package com.muxi.kolibreath.circleavatardemo;import android.content.Intent;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Matrix;import android.graphics.PointF;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.MotionEvent;import android.view.View;import android.widget.Button;import android.widget.ImageView;import java.io.ByteArrayOutputStream;/** * Created by kolibreath on 2016/12/18. */public class EditActivity extends AppCompatActivity implements View.OnClickListener{    private ImageView imageView_ready_to_process;    private Button button;    private Bitmap bitmap;    private Bitmap image;    private ImageView imageView_to_test;    private static final String TAG1 = "height";    @Override    protected void onCreate( Bundle savedInstanceState) {        int imageId[] = new int[]{R.drawable.face6};        super.onCreate(savedInstanceState);        setContentView(R.layout.process_pictures);        button = (Button) findViewById(R.id.sure_to_crop);        imageView_to_test= (ImageView) findViewById(R.id.image_to_test);        imageView_ready_to_process = (ImageView) findViewById(R.id.imageView_ready_to_process);        button.setOnClickListener(this);        TouchListener touchListener = new TouchListener();        imageView_ready_to_process.setOnTouchListener(touchListener);        imageView_ready_to_process.setImageResource(imageId[0]);    }    private final class TouchListener implements View.OnTouchListener{        private int mode = 0;        private static final int DRAG=1;        private static final int ZOOM=2;        private PointF startPoint = new PointF();        private Matrix matrix = new Matrix();        private Matrix currentMatrix = new Matrix();        private float startDis;        private PointF midPoint;        @Override        public boolean onTouch(View v, MotionEvent event) {            switch (event.getAction()&MotionEvent.ACTION_MASK){                case(MotionEvent.ACTION_DOWN):                    mode = DRAG;                    currentMatrix.set(imageView_ready_to_process.getImageMatrix());                    startPoint.set(event.getX(),event.getY());                    break;                case (MotionEvent.ACTION_MOVE):                    if(mode == DRAG){                        float dx = event.getX() - startPoint.x;                        float dy = event.getY() - startPoint.y;                        matrix.set(currentMatrix);                        matrix.postTranslate(dx,dy);                    }else if(mode == ZOOM){                        float lastDis = distance(event);                        if(lastDis>10f) {                            double scale = lastDis / startDis;                            matrix.set(currentMatrix);                            matrix.postScale((float) scale, (float) scale, midPoint.x, midPoint.y);                        }                    }                    break;                case MotionEvent.ACTION_UP:                case MotionEvent.ACTION_POINTER_UP:                    mode =0;                    break;                case MotionEvent.ACTION_POINTER_DOWN:                    mode = ZOOM;                    startDis = distance(event);                    if(startDis>10f){                        midPoint = middle(event);                        currentMatrix.set(imageView_ready_to_process.getImageMatrix());                    }                    break;            }            imageView_ready_to_process.setImageMatrix(matrix);            return true;        }    }    private float distance(MotionEvent event){        float dx = event.getX(1)- event.getX(0);        float dy = event.getY(1)- event.getY(0);        return (float)Math.sqrt(dx*dx +dy*dy);    }    private PointF middle(MotionEvent event){        float dx = (event.getX(1)- event.getX(0))/2;        float dy = (event.getY(1)- event.getY(0))/2;        return   new PointF(dx,dy);    }        @Override    public void onClick(View v) {        Intent intent = new Intent();        image = BitmapFactory.decodeResource(this.getResources(),R.drawable.face6);        bitmap = BitmapFactory.decodeResource(getResources(),R.drawable.face6);        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();        //CompressFormat 可以指定解析图片的格式，后面的一个int参数表示解析的质量        //解析的图片如果质量太高就会报错        bitmap.compress(Bitmap.CompressFormat.JPEG,10,byteArrayOutputStream);        byte[] bytes = byteArrayOutputStream.toByteArray();        intent.putExtra("bitmap",bytes);        imageView_to_test.setImageBitmap(BitmapFactory.decodeByteArray(bytes,0,bytes.length));        setResult(RESULT_OK,intent);        //不需要写startActivity()        finish();    }    }

然后这个demo就完成了，接下来的完整版我写完之后再放过来。