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我写了一小段代码，感谢stackoverflows用户，我使用“Flood fill”算法填充了图像的一些颜色不同的区域。问题是这个修改的结果没有放在屏幕的中心。见下文：

绿羊

我想这是因为我没有正确设置视图的参数，如下面的代码所示：

import java.util.LinkedList;
import java.util.Queue;

import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.Point;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;

public class Main extends Activity {

 // private RelativeLayout drawingLayout;
    private MyView myView;
 // public ImageView image;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

     //     setContentView(R.layout.activity_main);
     //     this.drawingLayout = (RelativeLayout) findViewById(R.id.drawingLayout);

     //     image = (ImageView) findViewById(R.id.immagine);

            this.myView = new MyView(Main.this);
            setContentView(myView);
    //      this.drawingLayout.addView(myView);
 }

public class MyView extends View {

     private Paint paint;
    private Path path;
    Bitmap mBitmap;
    ProgressDialog pd;
    final Point p1 = new Point();
    Canvas canvas;

     //Bitmap mutableBitmap ;
     public MyView(Context context) {

         super(context);

         this.paint = new Paint();
         this.paint.setAntiAlias(true);
         pd = new ProgressDialog(context);
         this.paint.setStyle(Paint.Style.STROKE);
        paint.setStrokeJoin(Paint.Join.ROUND);
        paint.setStrokeWidth(5f);
        mBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.leone).copy(Bitmap.Config.ARGB_8888, true);
         this.path = new Path();
     }

    @Override
    protected void onDraw(Canvas canvas) {
        this.canvas = canvas;
        this.paint.setColor(Color.RED);
        canvas.drawBitmap(mBitmap, 0, 0, paint);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {

        float x = event.getX();
        float y = event.getY();
        switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN:

            p1.x = (int) x;
            p1.y = (int) y;
            final int sourceColor = mBitmap.getPixel((int) x, (int) y);
            final int targetColor = paint.getColor();
            new TheTask(mBitmap, p1, sourceColor, targetColor).execute();
            invalidate();
        }
        return true;
    }

    public void clear() {
        path.reset();
        invalidate();
    }

    public int getCurrentPaintColor() {
        return paint.getColor();
    }

    class TheTask extends AsyncTask<Void, Integer, Void> {

        Bitmap bmp;
        Point pt;
        int replacementColor, targetColor;

        public TheTask(Bitmap bm, Point p, int sc, int tc) {
            this.bmp = bm;
            this.pt = p;
            this.replacementColor = tc;
            this.targetColor = sc;
            pd.setMessage("Filling....");
            pd.show();
        }

        @Override
        protected void onPreExecute() {
            pd.show();

        }

        @Override
        protected void onProgressUpdate(Integer... values) {

        }

        @Override
        protected Void doInBackground(Void... params) {
            FloodFill f = new FloodFill();
            f.floodFill(bmp, pt, targetColor, replacementColor);
            return null;
        }

        @Override
        protected void onPostExecute(Void result) {
            pd.dismiss();
            invalidate();
        }
    }
}

// flood fill
public class FloodFill {

    public void floodFill(Bitmap image, Point node, int targetColor, int replacementColor) {
        int width = image.getWidth();
        int height = image.getHeight();
        int target = targetColor;
        int replacement = replacementColor;
        if (target != replacement) {
            Queue<Point> queue = new LinkedList<Point>();
            do {

                int x = node.x;
                int y = node.y;
                while (x > 0 && image.getPixel(x - 1, y) == target) {
                    x--;

                }
                boolean spanUp = false;
                boolean spanDown = false;
                while (x < width && image.getPixel(x, y) == target) {
                    image.setPixel(x, y, replacement);
                    if (!spanUp && y > 0
                            && image.getPixel(x, y - 1) == target) {
                        queue.add(new Point(x, y - 1));
                        spanUp = true;
                    } else if (spanUp && y > 0
                            && image.getPixel(x, y - 1) != target) {
                        spanUp = false;
                    }
                    if (!spanDown && y < height - 1
                            && image.getPixel(x, y + 1) == target) {
                        queue.add(new Point(x, y + 1));
                        spanDown = true;
                    } else if (spanDown && y < height - 1
                            && image.getPixel(x, y + 1) != target) {
                        spanDown = false;
                    }
                    x++;
                }
            } while ((node = queue.poll()) != null);
        }
    }
}
}

是否可以将 ImageView 设置为可编辑，以便我可以使用 Flood Fill 算法而不是主视图对其进行着色？

您能告诉我如何将此图像设置为屏幕中心并正确调整其大小吗？

谢谢您的帮助！

4

1 回答 1

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1. 数学

您需要使用以下方法获取屏幕尺寸并调整 onTouchEvent 方法，如果我没有错误地考虑不同的尺寸。

如果您想要以像素为单位的显示尺寸，您可以使用getSize：

Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
int width = size.x;
int height = size.y;

如果您不在，您可以通过以下Activity方式获得默认值：DisplayWINDOW_SERVICE

WindowManager wm = (WindowManager) ctx.getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();

在getSize引入之前（在 API 级别 13 中），您可以使用现在已弃用的getWidth和方法：getHeight

Display display = getWindowManager().getDefaultDisplay(); 
int width = display.getWidth();  // deprecated
int height = display.getHeight();  // deprecated

2. 秤型。

扩展ImageView并使用此属性。

ifimgView是您想要居中的图像视图。然后做：

imgView.setScaleType(ImageView.ScaleType.CENTER);
于 2013-06-06T20:40:18.473 回答