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我正在使用列表视图来显示 res/drawable 文件夹中存在的一组图像。为此，我创建了一个适配器类，它将填充（main.xml）。我已经编写了这样的代码，如果单击 listItem，图像应该在新活动中全屏显示。我还需要包括图像缩放功能。你能帮他把缩放功能附加到下面的代码中吗？

MainActivity.java

public class MainActivity extends ListActivity 
{
 static final String[] Furniture_types = new String[] { "Type1", "Type2","Type3", "Type4"};

    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setListAdapter(new FurnitureArrayAdapter(this,Furniture_types ));
    }

    protected void onListItemClick(ListView l, View v, int position, long id) 
    {
        Intent myIntent = new Intent();
        myIntent.setClassName("com.mink7.furniture.list","com.mink7.furniture.list.ImageDisplayActivity");
        myIntent.putExtra("ID", id);
        startActivity(myIntent);

    }

}





FurnitureArrayAdapter.java

public class FurnitureArrayAdapter extends ArrayAdapter<String>
{
        private final Context context;
    private final String[] values;

    public FurnitureArrayAdapter(Context context, String[] values)
    {
        super(context, R.layout.activity_main, values);
        this.context = context;
        this.values = values;
    }


    public View getView(int position, View convertView, ViewGroup parent) 
    {
        LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View rowView = inflater.inflate(R.layout.activity_main, parent, false);
        TextView textView = (TextView) rowView.findViewById(R.id.type);
        ImageView imageView = (ImageView) rowView.findViewById(R.id.photo);
        textView.setText(values[position]);
        String s = values[position];

        System.out.println(s);

        if (s.equals("Type1")) {
            imageView.setImageResource(R.drawable.img1);
        } else if (s.equals("Type2")) {
            imageView.setImageResource(R.drawable.img2);
        } else if (s.equals("Type3")) {
            imageView.setImageResource(R.drawable.img3);
        } else {
            imageView.setImageResource(R.drawable.img4);
        }

        return rowView;
    }

}

ImageDisplayActivity.java

public class ImageDisplayActivity extends Activity
{
    protected void onCreate(Bundle savedInstanceState) 
    {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.imagedisp);
        Bundle extras = getIntent().getExtras();

        long id =extras.getLong("ID");
        String s=String.valueOf(id);
        ImageView image = (ImageView) findViewById(R.id.imageView1);


        System.out.println(s);

        if (s.equals("0")) 
        {
            image.setImageResource(R.drawable.img1);

        }
        else if (s.equals("1"))
        {
            image.setImageResource(R.drawable.img2);
        }
        else if (s.equals("2"))
        {
            image.setImageResource(R.drawable.img3);
        } 
        else 
        {
            image.setImageResource(R.drawable.img4);
        }



    }


}
4

1 回答 1

2

以下代码描述了一个实现某些方法来实现放大和缩小功能的类。您可以修改此代码并将其包含在您自己的类中。

import android.app.Activity;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.os.Bundle;
import android.util.FloatMath;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.ImageView;

public class ZoomInZoomOut extends Activity implements OnTouchListener 
{
    private static final String TAG = "Touch";
    @SuppressWarnings("unused")
    private static final float MIN_ZOOM = 1f,MAX_ZOOM = 1f;

    // These matrices will be used to scale points of the image
    Matrix matrix = new Matrix();
    Matrix savedMatrix = new Matrix();

    // The 3 states (events) which the user is trying to perform
    static final int NONE = 0;
    static final int DRAG = 1;
    static final int ZOOM = 2;
    int mode = NONE;

    // these PointF objects are used to record the point(s) the user is touching
    PointF start = new PointF();
    PointF mid = new PointF();
    float oldDist = 1f;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        ImageView view = (ImageView) findViewById(R.id.imageView);
        view.setOnTouchListener(this);
    }

    @Override
    public boolean onTouch(View v, MotionEvent event) 
    {
        ImageView view = (ImageView) v;
        view.setScaleType(ImageView.ScaleType.MATRIX);
        float scale;

        dumpEvent(event);
        // Handle touch events here...

        switch (event.getAction() & MotionEvent.ACTION_MASK) 
        {
            case MotionEvent.ACTION_DOWN:   // first finger down only
                                                savedMatrix.set(matrix);
                                                start.set(event.getX(), event.getY());
                                                Log.d(TAG, "mode=DRAG"); // write to LogCat
                                                mode = DRAG;
                                                break;

            case MotionEvent.ACTION_UP: // first finger lifted

            case MotionEvent.ACTION_POINTER_UP: // second finger lifted

                                                mode = NONE;
                                                Log.d(TAG, "mode=NONE");
                                                break;

            case MotionEvent.ACTION_POINTER_DOWN: // first and second finger down

                                                oldDist = spacing(event);
                                                Log.d(TAG, "oldDist=" + oldDist);
                                                if (oldDist > 5f) {
                                                    savedMatrix.set(matrix);
                                                    midPoint(mid, event);
                                                    mode = ZOOM;
                                                    Log.d(TAG, "mode=ZOOM");
                                                }
                                                break;

            case MotionEvent.ACTION_MOVE:

                                                if (mode == DRAG) 
                                                { 
                                                    matrix.set(savedMatrix);
                                                    matrix.postTranslate(event.getX() - start.x, event.getY() - start.y); // create the transformation in the matrix  of points
                                                } 
                                                else if (mode == ZOOM) 
                                                { 
                                                    // pinch zooming
                                                    float newDist = spacing(event);
                                                    Log.d(TAG, "newDist=" + newDist);
                                                    if (newDist > 5f) 
                                                    {
                                                        matrix.set(savedMatrix);
                                                        scale = newDist / oldDist; // setting the scaling of the
                                                                                    // matrix...if scale > 1 means
                                                                                    // zoom in...if scale < 1 means
                                                                                    // zoom out
                                                        matrix.postScale(scale, scale, mid.x, mid.y);
                                                    }
                                                }
                                                break;
        }

        view.setImageMatrix(matrix); // display the transformation on screen

        return true; // indicate event was handled
    }

    /*
     * --------------------------------------------------------------------------
     * Method: spacing Parameters: MotionEvent Returns: float Description:
     * checks the spacing between the two fingers on touch
     * ----------------------------------------------------
     */

    private float spacing(MotionEvent event) 
    {
        float x = event.getX(0) - event.getX(1);
        float y = event.getY(0) - event.getY(1);
        return FloatMath.sqrt(x * x + y * y);
    }

    /*
     * --------------------------------------------------------------------------
     * Method: midPoint Parameters: PointF object, MotionEvent Returns: void
     * Description: calculates the midpoint between the two fingers
     * ------------------------------------------------------------
     */

    private void midPoint(PointF point, MotionEvent event) 
    {
        float x = event.getX(0) + event.getX(1);
        float y = event.getY(0) + event.getY(1);
        point.set(x / 2, y / 2);
    }

    /** Show an event in the LogCat view, for debugging */
    private void dumpEvent(MotionEvent event) 
    {
        String names[] = { "DOWN", "UP", "MOVE", "CANCEL", "OUTSIDE","POINTER_DOWN", "POINTER_UP", "7?", "8?", "9?" };
        StringBuilder sb = new StringBuilder();
        int action = event.getAction();
        int actionCode = action & MotionEvent.ACTION_MASK;
        sb.append("event ACTION_").append(names[actionCode]);

        if (actionCode == MotionEvent.ACTION_POINTER_DOWN || actionCode == MotionEvent.ACTION_POINTER_UP) 
        {
            sb.append("(pid ").append(action >> MotionEvent.ACTION_POINTER_ID_SHIFT);
            sb.append(")");
        }

        sb.append("[");
        for (int i = 0; i < event.getPointerCount(); i++) 
        {
            sb.append("#").append(i);
            sb.append("(pid ").append(event.getPointerId(i));
            sb.append(")=").append((int) event.getX(i));
            sb.append(",").append((int) event.getY(i));
            if (i + 1 < event.getPointerCount())
                sb.append(";");
        }

        sb.append("]");
        Log.d("Touch Events ---------", sb.toString());
    }
}
于 2012-11-03T06:21:38.243 回答