圖片縮放，可裁剪的封裝類

package com.example.administrator.text.widget;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PointF;
import android.graphics.RectF;
import android.graphics.drawable.BitmapDrawable;
import android.media.ThumbnailUtils;
import android.os.Environment;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;

import java.io.File;
import java.io.FileOutputStream;
import java.util.Timer;
import java.util.TimerTask;

/**
 * Created by Administrator on 2016/9/28.
 */
public class ScaleImageView extends android.support.v7.widget.AppCompatImageView {

    public static final int SCALE = 2;
    public static final int DRAG = 1;
    public static final int NONE = 0;

    public int mode = NONE;

    //縮放比率
    public static final float MAX = 3f;
    public static final int MIN = 1;

    Bitmap bmp;

    //屏幕寬度
    int width;

    //
    PointF moveFinger = new PointF();

    PointF scaleCenter = new PointF();

    Matrix martix;

    float twoDis = 0;

    //畫筆
    Paint paint;

    //java代碼創建
    public ScaleImageView(Context context) {
        super(context);
        init();
    }

    //xml中創建
    public ScaleImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, widthMeasureSpec);
    }

    public void init() {
        setBackgroundColor(Color.rgb(0x31, 0x33, 0x35));
        //很重要的方法
        setScaleType(ScaleType.MATRIX);
        width = getResources().getDisplayMetrics().widthPixels;
        //設置畫筆
        paint = new Paint();
        paint.setAntiAlias(true);
        paint.setDither(true);
        paint.setColor(Color.argb(0x80, 0XFF, 0XFF, 0XFF));
        paint.setStrokeWidth(2);
    }

    boolean isShowLine = false;

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        paint.setARGB(0X80, 0XFF, 0XFF, 0XFF);
        if (isShowLine) {
            for (int i = 0; i < 2; i++) {
                canvas.drawLine(width / 3 * (i + 1), 0, width / 3 * (i + 1), width, paint);
                canvas.drawLine(0, width / 3 * (i + 1), width, width / 3 * (i + 1), paint);
            }
        }
    }


    //獲取圖片
    public String getScaleBitmap() {
        Bitmap bmp = Bitmap.createBitmap(width, width, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(bmp);
        paint.setARGB(0xFF, 0XFF, 0XFF, 0XFF);
        canvas.drawBitmap(this.bmp, martix, paint);
        //上傳 文件
        String name = "";
        try {
            name = new File(Environment.getExternalStorageDirectory().getAbsolutePath(), System.currentTimeMillis() + ".png").getAbsolutePath();
            FileOutputStream fio = new FileOutputStream(name);
            bmp.compress(Bitmap.CompressFormat.PNG, 100, fio);
            fio.flush();
            fio.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return name;
   /*     //獲取當前圖片
        //Bitmap src = ((BitmapDrawable) getDrawable()).getBitmap();
        //獲取圖片的位置
        RectF rectf = new RectF(0, 0, bmp.getWidth(), bmp.getHeight());
        martix.mapRect(rectf);
        //最終的取的圖片部分
        Rect rectsrc = new Rect(-(int) rectf.left, - (int) rectf.top, -(int) rectf.left+width, - (int) rectf.top+width);
        Log.e("TAG", rectsrc.toString());
        Log.e("TAG", "-----------" + (int) rectf.left + " " + (int) rectf.top + "  " + (int) rectf.right + "  " + (int) rectf.bottom);
        //目標的圖片部分
        Rect rectdst = new Rect(0, 0, width, width);

        canvas.drawBitmap(this.bmp, rectsrc, rectdst, paint);
        canvas.save();
        //  bmp.recycle();
        try {
            bmp.compress(Bitmap.CompressFormat.PNG, 100, new FileOutputStream(Environment.getExternalStorageDirectory().getAbsolutePath() + "/temp.png"));
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }*/
    }

    //設置圖片
    @Override
    public void setImageBitmap(Bitmap bm) {
        if (bm == null)
            return;
        //圖片矩陣運算
        martix = new Matrix();
        //放大到鋪滿全屏
        //判斷圖片的高寬是否大於width
        if (bm.getWidth() < width || bm.getHeight() < width) {
            //取最小值
            int min = Math.min(bm.getWidth(), bm.getHeight());
            //放大多少呢？
            float rate = width * 1.0f / min;
            // 放大
            this.bmp = ThumbnailUtils.extractThumbnail(bm, (int) (bm.getWidth() * rate), (int) (bm.getHeight() * rate));
        } else
            this.bmp = bm;
        setImageMatrix(martix);
        super.setImageBitmap(bmp);
    }

    Timer timer;

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        isShowLine = true;
        if (timer != null)
            timer.cancel();
        //如果需要拿多指觸碰
        switch (event.getAction() & MotionEvent.ACTION_MASK) {
            case MotionEvent.ACTION_DOWN:
                //按下的時候，記住你的手指頭
                moveFinger.set(event.getX(), event.getY());
                mode = DRAG;
                break;
            case MotionEvent.ACTION_POINTER_DOWN:
                //記錄放大的中心點
                //設置中心店
                scaleCenter = centerPoint(event);
                mode = SCALE;
                twoDis = twoMove(event);
                break;
            case MotionEvent.ACTION_UP:
                mode = NONE;
                //位置復位
                reSet();
                //關閉線條
                timer = new Timer();
                timer.schedule(new TimerTask() {
                    @Override
                    public void run() {
                        isShowLine = false;
                        //子線程重繪
                        postInvalidate();
                    }
                }, 1000);
                break;
            case MotionEvent.ACTION_POINTER_UP:
                mode = DRAG;
                //縮放復位
                reScaleSet();
                break;
            case MotionEvent.ACTION_MOVE:
                if (mode == DRAG) {
                    //拖拽
                    PointF pointf = calcDistance(event);
                    //x y 移動的距離
                    martix.postTranslate(pointf.x, pointf.y);
                    //記錄移動後的點
                    moveFinger.set(event.getX(), event.getY());
                } else if (mode == SCALE) {
                    //當前的距離
                    float dis = twoMove(event) / twoDis;
                    martix.postScale(dis, dis, scaleCenter.x, scaleCenter.y);
                }
                break;
        }
        setImageMatrix(martix);
        return true;
    }

    private void reScaleSet() {
        float values[] = new float[9];
        martix.getValues(values);
        Log.e("TAG", "------縮放" + values[0]);
        if (values[0] < MIN) {
            values[0] = MIN;
            values[4] = MIN;
        }
        if (values[0] > MAX) {
            values[0] = MAX;
            values[4] = MAX;
        }
        martix.setValues(values);
        Bitmap src = ((BitmapDrawable) getDrawable()).getBitmap();
        Log.e("TAG", src.getWidth() + "    " + src.getHeight());
    }

    //復位
    public void reSet() {
        RectF rectf = new RectF(0, 0, bmp.getWidth(), bmp.getHeight());
        //計算當前圖片在矩陣的位置
        martix.mapRect(rectf);
        Log.e("TAG", rectf.left + "  " + rectf.right + "  " + rectf.top + "   " + rectf.bottom);
        float x = 0;
        float y = 0;
        //水平方向
        if (rectf.left > 0) {
            x = -rectf.left;
        } else if (rectf.right < width) {
            x = width - rectf.right;
        }
        //垂直方向
        if (rectf.top > 0)
            y = -rectf.top;
        else if (rectf.bottom < width)
            y = width - rectf.bottom;
        martix.postTranslate(x, y);
    }


    //計算兩點之間的距離
    public PointF calcDistance(MotionEvent event) {
        float x = event.getX();
        float y = event.getY();
        PointF pointf = new PointF(x - moveFinger.x, y - moveFinger.y);
        return pointf;
    }


    public PointF centerPoint(MotionEvent event) {
        float x = event.getX(0) + event.getX(1);
        float y = event.getY(0) + event.getY(1);
        return new PointF(x / 2, y / 2);
    }

    //兩點移動距離
    public float twoMove(MotionEvent event) {
        float x = event.getX(0) - event.getX(1);
        float y = event.getY(0) - event.getY(1);
        return x * x + y * y;
    }


    @Override
    public boolean dispatchTouchEvent(MotionEvent event) {
        getParent().requestDisallowInterceptTouchEvent(true);
        return super.dispatchTouchEvent(event);
    }
}

用法：

1.複製代碼到工程目錄下

2.xml中直接加入下面代碼就好

    <com.example.administrator.text.widget.ScaleImageView
        android:id="@+id/siv_img"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

3.