【问题标题】:ImageView onTouchListener: cant touch the imageview behindImageView onTouchListener:不能触摸后面的imageview
【发布时间】:2013-11-25 07:49:58
【问题描述】:

我得到了一个 imageview 转换的教程,我真的需要 w/c。 here is the link。它工作正常,但我需要进行一些修改。我的问题是,当我添加第二个 imageview 时,我无法修改我添加的第一个 imageview。似乎我无法触摸它,因为它在第二个视图后面。我已经阅读了链接中的评论,也就是在询问这个问题,他通过 settag 和 gettag 解决了这个问题。我不知道该怎么做。有什么建议吗?谢谢。

public class MainActivity extends Activity implements OnTouchListener {

    // these matrices will be used to move and zoom image
    private Matrix matrix = new Matrix();
    private Matrix savedMatrix = new Matrix();
    // we can be in one of these 3 states
    private static final int NONE = 0;
    private static final int DRAG = 1;
    private static final int ZOOM = 2;
    private int mode = NONE;
    // remember some things for zooming
    private PointF start = new PointF();
    private PointF mid = new PointF();
    private float oldDist = 1f;
    private float d = 0f;
    private float newRot = 0f;
    private float[] lastEvent = null;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ImageView view = (ImageView) findViewById(R.id.imageView);
        ImageView view2 = (ImageView) findViewById(R.id.imageView2);
        view.setOnTouchListener(this);
        view2.setOnTouchListener(this);
    }

    public boolean onTouch(View v, MotionEvent event) {
        // handle touch events here
        ImageView view = (ImageView) v;
        switch (event.getAction() & MotionEvent.ACTION_MASK) {
            case MotionEvent.ACTION_DOWN:
                savedMatrix.set(matrix);
                start.set(event.getX(), event.getY());
                mode = DRAG;
                lastEvent = null;
                break;
            case MotionEvent.ACTION_POINTER_DOWN:
                oldDist = spacing(event);
                if (oldDist > 10f) {
                    savedMatrix.set(matrix);
                    midPoint(mid, event);
                    mode = ZOOM;
                }
                lastEvent = new float[4];
                lastEvent[0] = event.getX(0);
                lastEvent[1] = event.getX(1);
                lastEvent[2] = event.getY(0);
                lastEvent[3] = event.getY(1);
                d = rotation(event);
                break;
            case MotionEvent.ACTION_UP:
            case MotionEvent.ACTION_POINTER_UP:
                mode = NONE;
                lastEvent = null;
                break;
            case MotionEvent.ACTION_MOVE:
                if (mode == DRAG) {
                    matrix.set(savedMatrix);
                    float dx = event.getX() - start.x;
                    float dy = event.getY() - start.y;
                    matrix.postTranslate(dx, dy);
                } else if (mode == ZOOM) {
                    float newDist = spacing(event);
                    if (newDist > 10f) {
                        matrix.set(savedMatrix);
                        float scale = (newDist / oldDist);
                        matrix.postScale(scale, scale, mid.x, mid.y);
                    }
                    if (lastEvent != null && event.getPointerCount() == 2) {
                        newRot = rotation(event);
                        float r = newRot - d;
                        float[] values = new float[9];
                        matrix.getValues(values);
                        float tx = values[2];
                        float ty = values[5];
                        float sx = values[0];
                        float xc = (view.getWidth() / 2) * sx;
                        float yc = (view.getHeight() / 2) * sx;
                        matrix.postRotate(r, tx + xc, ty + yc);
                    }
                }
                break;
        }

       view.setImageMatrix(matrix);
        return true;
    }


    /**
     * Determine the space between the first two fingers
     */
    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);
    }

    /**
     * Calculate the mid point of the first 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);
    }

    /**
     * Calculate the degree to be rotated by.
     *
     * @param event
     * @return Degrees
     */
    private float rotation(MotionEvent event) {
        double delta_x = (event.getX(0) - event.getX(1));
        double delta_y = (event.getY(0) - event.getY(1));
        double radians = Math.atan2(delta_y, delta_x);
        return (float) Math.toDegrees(radians);
    }
}


<?xml version="1.0" encoding="utf-8"?>

<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">

<ImageView android:id="@+id/imageView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:scaleType="matrix"
 android:src="@drawable/chill"
 />

<ImageView
    android:id="@+id/imageView2"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
android:scaleType="matrix" 
    android:src="@drawable/awesome"
   />


</FrameLayout>

【问题讨论】:

    标签: java android imageview touch-event ontouchlistener


    【解决方案1】:

    试试这个:

    在您的 xml 文件中使用 android:tag 为您的图像设置标签,并在运行时获取标签并将转换应用于该特定图像。

    1.在java类中实现一个方法,

    2.点击任一图片时调用该方法,

    3.并通过使用 View.getTag() 获取其标签来识别图像;并应用转换。

    【讨论】:

    • 我的问题是我在添加第二个 ImageView 时无法触摸添加的第一个 imageview。知道如何访问第一张图片吗?
    • 使用框架布局,我将一张图片放在另一张图片上,为两张图片提供了点击事件,并且能够访问这两张图片。让我知道您遇到的问题。
    • @ JIGAR PANDYA:我通过单击按钮以编程方式添加图像视图。 imageview 将被添加到框架布局中。当我添加第一个图像视图时,转换工作正常,但是当我单击按钮添加第二个图像视图时,第一个视图位于第二个视图下方,因此它变得不可触摸。我唯一可以触摸的是我添加的最新视图。希望你能帮忙:)
    • 嘿兄弟!我刚试过你说的东西,它工作得很好:)
    • @JIGAR PANDYA:哇,太好了,你是怎么做到的?我将粘贴示例代码,请检查。
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