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：

1、使用系统相机拍照，拍完返回，对图片进行压缩和存储。

2、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。

3、根据坐标信息生成裁剪图片并存储。

部分核心代码：

1、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);

2、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;
    }
}

3、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>

4、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;
    }
 
    /**
     * 判断是否相应的图片格式
     */
    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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