Android怎么实现手势划定区域裁剪图片

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需求：

拍照，然后对图片进行处理，划定矩形区域，将矩形区域裁剪下来

思路：

使用系统相机拍照，拍完返回，对图片进行压缩和存储。

新建一个activity处理图片裁剪，利用自定义view在画布上画出矩形区域。

根据坐标信息生成裁剪图片并存储。

部分核心代码：

调用系统相机拍照

String IMAGE_PATH = Environment.getExternalStorageDirectory().getPath()+ "/com.kwmax.demo/Image/";String filename = "xxxxxx.jpeg";File picFile = new File(IMAGE_PATH + filename);if (!picFile.exists()) {    picFile.createNewFile();} ...if(getContext().getPackageManager().getLaunchIntentForPackage("com.sec.android.app.camera") != null) {    cameraIntent.setPackage("com.sec.android.app.camera");}if (getContext().getPackageManager().getLaunchIntentForPackage("com.android.hwcamera") != null) {    cameraIntent.setPackage("com.android.hwcamera");}if (getContext().getPackageManager().getLaunchIntentForPackage("com.zte.camera") != null) {    cameraIntent.setPackage("com.zte.camera");}cameraIntent.setAction(MediaStore.ACTION_IMAGE_CAPTURE); // 默认系统相机cameraIntent.addCategory("android.intent.category.DEFAULT"); Uri pictureUri = Uri.fromFile(picFile);cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, pictureUri);startActivityForResult(intent, CAMERA_REQUEST_CODE);

自定义手势矩形view

public class CaptureRectView extends View {    private int x;    private int y;    private int m;    private int n;    private boolean sign;//绘画标记位    private Paint paint;//画笔     public CaptureRectView (Context context) {        super(context);        paint = new Paint(Paint.FILTER_BITMAP_FLAG);    }     @Override    protected void onDraw(Canvas canvas) {        if(sign){            paint.setColor(Color.TRANSPARENT);        }else{            paint.setColor(Color.RED);            paint.setAlpha(80);            paint.setStyle(Paint.Style.STROKE);            paint.setStrokeWidth(15f);            canvas.drawRect(new Rect(x, y, m, n), paint);        }        super.onDraw(canvas);    }     public void setSeat(int x,int y,int m,int n){        this.x = x;        this.y = y;        this.m = m;        this.n = n;    }     public boolean isSign() {        return sign;    }     public void setSign(boolean sign) {        this.sign = sign;    }}

裁剪页面布局

<?xml version="1.0" encoding="utf-8"?><FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"                android:id="@+id/drawrect_framelayout"                android:layout_width="fill_parent"                android:layout_height="fill_parent"                android:background="@color/black"                android:clickable="true"                android:orientation="vertical">     <RelativeLayout        android:id="@+id/drawrect_relativelayout"        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:background="@color/black"        android:orientation="vertical">         <FrameLayout            android:layout_width="match_parent"            android:layout_height="match_parent"            android:layout_above="@+id/bottom">            <LinearLayout                android:id="@+id/image_zoom_view_layout"                android:layout_width="match_parent"                android:layout_height="match_parent"                android:layout_centerInParent="true"                android:gravity="center"                android:orientation="vertical"/>            <ImageView                android:id="@+id/capture_preview"                android:layout_width="80dp"                android:layout_height="80dp"/>        </FrameLayout>        <LinearLayout            android:id="@+id/bottom"            android:layout_width="fill_parent"            android:layout_height="50dip"            android:layout_alignParentBottom="true"            android:orientation="horizontal"            android:layout_marginLeft="10dp"            android:layout_marginRight="10dp">             <Button                android:id="@+id/btn_capture"                android:layout_width="50dp"                android:layout_height="wrap_content"                android:layout_weight="1"                android:layout_marginRight="10dp"                android:text="裁剪"/>             <Button                android:id="@+id/btn_cancel"                android:layout_width="50dp"                android:layout_height="wrap_content"                android:layout_weight="1"                android:text="取消"/>         </LinearLayout>     </RelativeLayout> </FrameLayout>

裁剪activity

public class DrawRectActivity extends BasicActivity implements OnClickListener, View.OnTouchListener {     private String TAG = "DrawRectActivity";    private String imageString;    private String imagePath;    private ArrayList<String> imageList = null;    private int position = 0;    private int width, height;    private LinearLayout layerViewLayout = null;     private ImageView aiPreview;    private CaptureRectView captureView;//绘画选择区域    private int capX;//绘画开始的横坐标    private int capY;//绘画开始的纵坐标    private int capM;//绘画结束的横坐标    private int capN;//绘画结束的纵坐标    private Bitmap captureBitmap;     private Button cancel;    private Button aiCapture;     private FrameLayout frameLayout;    private RelativeLayout relativeLayout;     @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        init();        initUI();    }     private void init() {        width = ImageUtils.getScreenWidth(this);        height = ImageUtils.getScreenHeight(this);        Intent intent = this.getIntent();        Bundle bundle = intent.getExtras();        imageString = bundle.getString("imageString");        imagePath = bundle.getString("imagePath");        position = bundle.getInt("position");        imageList = parseImageString(imagePath, imageString);     }     @TargetApi(Build.VERSION_CODES.JELLY_BEAN)    private void initUI() {        setContentView(R.layout.draw_image_rect_view);        frameLayout = (FrameLayout) findViewById(R.id.drawrect_framelayout);        relativeLayout = (RelativeLayout) findViewById(R.id.drawrect_relativelayout);        layerViewLayout = (LinearLayout) this.findViewById(R.id.image_zoom_view_layout);        btncancel = (Button) findViewById(R.id.btn_cancel);        btnCapture = (Button) findViewById(R.id.btn_capture);        btnPreview = (ImageView) findViewById(R.id.capture_preview);         ImageView originImage = new ImageView(this);        Bitmap image = ImageUtils.getBitmapFromFile(imagePath + imageList.get(position), 1);        originImage.setImageBitmap(image);        originImage.setLayerType(View.LAYER_TYPE_SOFTWARE, null);        layerViewLayout.addView(originImage, new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));         captureView = new CaptureRectView(this);        originImage.setOnTouchListener(this);        this.addContentView(captureView, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));         if (frameLayout.isClickable()) {            frameLayout.setOnClickListener(new OnClickListener() {                @Override                public void onClick(View v) {                }            });        }        btncancel.setOnClickListener(this);        btnCapture.setOnClickListener(this);     }     private ArrayList<String> parseImageString(String imagePath, String imageString) {        ArrayList<String> list = new ArrayList<String>();        String allFiles = imageString.substring(imageString.indexOf("img://") + "img://".length());        String fileName = null;        while (allFiles.indexOf(";") > 0) {            fileName = allFiles.substring(0, allFiles.indexOf(";"));            allFiles = allFiles.substring(allFiles.indexOf(";") + 1);            if (checkIsImageFile(fileName) && new File(imagePath + fileName).exists()) {                list.add(fileName);                Log.v("ParseImageString()", "imageName=" + fileName);            } else {                Log.v("ParseImageString()", "bad imageName=" + fileName);            }         }        Log.v("ParseImageString()", "imagelist.size=" + list.size());        return list;    }         private boolean checkIsImageFile(String fName) {        boolean isImageFormat;        if (fName.endsWith(".jpg") || fName.endsWith(".gif") || fName.endsWith(".png") || fName.endsWith(".jpeg") || fName.endsWith(".bmp")) {            isImageFormat = true;        } else {            isImageFormat = false;        }        return isImageFormat;    }     @Override    public boolean onTouch(View view, MotionEvent event) {        switch (event.getAction()) {            case MotionEvent.ACTION_DOWN:                capX = 0;                capY = 0;                width = 0;                height = 0;                capX = (int) event.getX();                capY = (int) event.getY();                break;            case MotionEvent.ACTION_MOVE:                capM = (int) event.getX();                capN = (int) event.getY();                captureView.setSeat(capX, capY, capM, capN);                captureView.postInvalidate();                break;            case MotionEvent.ACTION_UP:                if (event.getX() > capX) {                    width = (int) event.getX() - capX;                } else {                    width = (int) (capX - event.getX());                    capX = (int) event.getX();                }                if (event.getY() > capY) {                    height = (int) event.getY() - capY;                } else {                    height = (int) (capY - event.getY());                    capY = (int) event.getY();                }                captureBitmap = getCapturePreview(this);                if (null != captureBitmap) {                    btnPreview.setImageBitmap(captureBitmap);                }                break;        }        if (captureView.isSign()) {            return false;        } else {            return true;        }    }     private Bitmap getCapturePreview(Activity activity) {        View view = activity.getWindow().getDecorView();        view.setDrawingCacheEnabled(true);        view.buildDrawingCache();        Bitmap bitmap = view.getDrawingCache();        Rect frame = new Rect();        activity.getWindow().getDecorView().getWindowVisibleDisplayFrame(frame);        int toHeight = frame.top;        //todo:这里需要针对部分机型做适配        if (width > 0 && height > 0) {            bitmap = Bitmap.createBitmap(bitmap, capX, capY + 240, width, height);            view.setDrawingCacheEnabled(false);            return bitmap;        } else {            return null;        }    }     @Override    public void onClick(View v) {         switch (v.getId()) {            case R.id.btn_cancel:                Intent cancelintent = getIntent();                createPendingResult(600, cancelintent, PendingIntent.FLAG_UPDATE_CURRENT);                setResult(RESULT_OK, cancelintent);                finish();                break;            case R.id.btn_capture:                Intent sureintent = getIntent();                createPendingResult(CpAIphotoAttributes.PHOTO_CAPTURE, sureintent, PendingIntent.FLAG_UPDATE_CURRENT);                if (captureBitmap != null) {                                      try {                        String file = IMAGE_PATH;                        String randomid = UUID.randomUUID().toString();                        String filename = randomid+ ".jpeg";                        FileOutputStream fout = new FileOutputStream(file+filename);                        captureBitmap.compress(Bitmap.CompressFormat.JPEG, 100, fout);                        sureintent.putExtra("capturePath", file+filename);                        sureintent.putExtra("capturefilename", filename);                        sureintent.putExtra("capturefileid", randomid);                    } catch (FileNotFoundException e) {                        e.printStackTrace();                    }                }                setResult(RESULT_OK, sureintent);                finish();                break;            default:                break;        }    }      @Override    public boolean onKeyDown(int keyCode, KeyEvent event) {        switch (keyCode) {            case KeyEvent.KEYCODE_BACK:                Intent cancelintent = getIntent();                createPendingResult(600, cancelintent, PendingIntent.FLAG_UPDATE_CURRENT);                cancelintent.putExtra("imagePath", imagePath);                cancelintent.putExtra("position", position);                cancelintent.putExtra("todowhat", "cancel");                setResult(RESULT_OK, cancelintent);                finish();                break;            default:                break;        }        return false;    }     @Override    public void finish() {        super.finish();    }     @Override    protected void onActivityResult(int requestCode, int resultCode, Intent data) {         if (resultCode == RESULT_OK) {            switch (requestCode) {                case 400:                    String text = null;                    Log.v("DrawRectActivity", "onActivityReault imagePath=" + imagePath + imageList.get(position));                    if (StringUtil.isNotBlank(text)) {                        Log.v("DrawRectActivity", "onActivityReault imagePath=" + imagePath + imageList.get(position) + ";text=" + text);                    } else {                     }                    break;                default:                    break;            }        }        super.onActivityResult(requestCode, resultCode, data);    }     @Override    protected void onDestroy() {        super.onDestroy();    } }

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