双指缩放的ListView的Android [英] Pinch Zoom ListView Android
问题描述
我想实现一个捏放大在Android上一个ListView和我现在面临一个问题,当我点击并拖动缩放列表视图。 首先,这里的code:
I'm trying to implement a pinch to zoom in a listview on Android and I'm facing a problem when I click and drag the zoomed list view. First, here's the code:
public class ScaleListView extends ListView {
private ScaleGestureDetector mScaleDetector;
private float mScaleFactor = 1.f;
private float x = 0;
private float y = 0;
private float startx = 0;
private float starty = 0;
private boolean canClick = true;
private float xtranslation = 0;
public ScaleListView(Context context, AttributeSet attrs) {
super(context, attrs);
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
if (ev.getAction() == MotionEvent.ACTION_DOWN) {
startx = ev.getX();
starty = ev.getY();
}
if (ev.getPointerCount() > 1) {
y = ev.getY();
x = ev.getX();
} else if (ev.getAction() == MotionEvent.ACTION_UP) {
canClick = (ev.getX() - startx) == 0 && (ev.getY() - starty) == 0 && mScaleFactor == 1;
} else if(ev.getAction() == MotionEvent.ACTION_MOVE){
xtranslation = ev.getX() - startx;
}
mScaleDetector.onTouchEvent(ev);
return super.onTouchEvent(ev);
}
@Override
public void onDraw(Canvas canvas) {
canvas.scale(mScaleFactor, mScaleFactor, x , y);
canvas.translate(xtranslation, 0);
super.onDraw(canvas);
}
private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
@Override
public boolean onScale(ScaleGestureDetector detector) {
canClick = false;
mScaleFactor *= detector.getScaleFactor();
// Don't let the object get too small or too large.
mScaleFactor = Math.max(0.1f, Math.min(mScaleFactor, 5.0f));
if (mScaleFactor <= 1) {
mScaleFactor = 1;
canClick = true;
}
xPos = ScaleListView.this.getWidth() - detector.getFocusX();
ScaleListView.this.invalidate();
return true;
}
}
public boolean canClick(){
return canClick;
}
现在的问题是与翻译。它去无限的,我可以水平拖动它,并采取列表视图关闭视口。所以,我无法面对如何把一个边缘到翻译... 感谢您的帮助。
The problem is with the translation. It goes infinite, I can drag it horizontally and take the list view off the viewport. So I can't face how to put an edge to the translation... Thanks for any help.
推荐答案
我只是把一个工人阶级这一点。 让我知道,如果你的作品。 https://github.com/Xjasz/AndroidZoomableViewGroup
I just put together a working class for this. Let me know if it works for you. https://github.com/Xjasz/AndroidZoomableViewGroup
这篇关于双指缩放的ListView的Android的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!