Question

我有一个framelayout，它有一个背景图片和一些图像视图。它还有一些嵌套布局（如Relative）。无论如何，我想要实现的是放大/缩小和平移的能力。我用的是gesturedetection和setScaleX / setScaleY和translateX / tranlsateY的方法

它确实可以完成部分工作，但是翻译有时可以将整个布局从屏幕上移除，还有其他一些小问题。

你推荐一种做事方式，还是有我可以参考的代码？

谢谢

Answer 1

查看此网址[https://github.com/sephiroth74/ImageViewZoom][1].This可能对您有帮助。

为＆＃34; Touch＆＃34;创建一个新课程

public class Touch实现了OnTouchListener {

Matrix matrix = new Matrix();
Matrix savedMatrix = new Matrix();
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;

@Override
public boolean onTouch(View v, MotionEvent event) {
    ImageView view = (ImageView) v;
    dumpEvent(event);
    switch (event.getAction() & MotionEvent.ACTION_MASK) {
        case MotionEvent.ACTION_DOWN:
            savedMatrix.set(matrix);
            start.set(event.getX(), event.getY());
            mode = DRAG;
            break;
        case MotionEvent.ACTION_POINTER_DOWN:
            oldDist = spacing(event);
            if (oldDist > 10f) {
                savedMatrix.set(matrix);
                midPoint(mid, event);
                mode = ZOOM;
            }
            break;
        case MotionEvent.ACTION_UP:
        case MotionEvent.ACTION_POINTER_UP:
            mode = NONE;
            break;
        case MotionEvent.ACTION_MOVE:
            if (mode == DRAG) {
                matrix.set(savedMatrix);
                matrix.postTranslate(event.getX() - start.x, event.getY() - start.y);
            } 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);
                }
            }
            break;
    }

    view.setImageMatrix(matrix);
    return true; // indicate event was handled
}

/** 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("]");
}

/** 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);
}}

2。按以下方式更改您的Activity类：

 FrameLayout fm =(FrameLayout)findViewById(R.id.fm);
 fm.setOnTouchListener(new Touch());

Answer 2

您的要求与Read about Java's heap size的非常相似。

您可以参考实施此或与此类似的内容。

1）KenBurns effect

2）KenBurnsView

3）JBKenBurns

我个人使用其中一种而且没有任何问题。

祝你好运。

缩放/平移具有图像视图的framelayout

2 个答案: