问题描述
由于任何形状（无论是实心圆，星星，三角形，位图与透明区域等），我想知道这是否是可能的（采用了最新的Android API）知道，如果用户点击视图，或它的外面。
Given any shape (either filled circle, star, triangle, bitmap with transparent areas, etc.) I would like to know if it's possible (using the latest Android API) to know if the user has clicked on the view, or outside of it.
例如，如果我有一个圆形的按钮，我想知道，如果用户点击圆圈内，而不是外在的了。
For example, if I have a circular button, I would like to know if the user has clicked inside the circle, but not outside of it.
这可能吗？
如果没有，也许我可以轮询触摸事件的像素，如果它是透明的，忽略它，如果它不是，处理它作为一个click事件？
If not, maybe I could poll the pixel of the touch event, and if it's transparent, ignore it, and if it isn't, handle it as a click event?
推荐答案
好了，我已经找到了为任何类型的视图是一个有效方法。
ok, i've found a working solution for any type of view.
一些注意事项：
-
可悲它使用视图的大小的位图，但仅用于时间微量
sadly it uses a bitmap of the size of the view, but only for a tiny amount of time.
之后，它保存在那里它被认为在可视区域和在那里它被认为可见区域之外。
after that, it holds where it's considered on the visible area and where it's considered outside of the visible area.
我可以使通过整数，其中有标志的数组它更多的内存友好。目前，它是一个简单的布尔数组。
i could make it more memory friendly by making an array of integers, which have flags. currently it's a simple boolean array.
我可以在JNI检查位图的Alpha值，而是和避免的（短）的时间在那里我有两个位图和排列在一起。
i could check the bitmap's alpha values in JNI instead, and avoid having the (short) time where i have both the bitmap and the array together.
如果有人可以帮助做的更好，也可能是真正伟大的。
if anyone could help making it better, it could be really great.
这里的code：
public class MainActivity extends Activity
{
boolean[] _inVisibleAreaMap;
private int _width,_height;
@Override
protected void onCreate(final Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final View view=findViewById(R.id.imageView1);
view.setDrawingCacheEnabled(true);
runJustBeforeBeingDrawn(view,new Runnable()
{
@Override
public void run()
{
final Bitmap bitmap=view.getDrawingCache();
_width=bitmap.getWidth();
_height=bitmap.getHeight();
_inVisibleAreaMap=new boolean[_width*_height];
for(int y=0;y<_width;++y)
for(int x=0;x<_height;++x)
_inVisibleAreaMap[y*_width+x]=Color.alpha(bitmap.getPixel(x,y))!=0;
view.setDrawingCacheEnabled(false);
bitmap.recycle();
}
});
view.setOnTouchListener(new OnTouchListener()
{
@Override
public boolean onTouch(final View v,final MotionEvent event)
{
final int x=(int)event.getX(),y=(int)event.getY();
boolean isIn=x>=0&&y>=0&&x<_width&&y<_height;
// if inside bounding box , check if in the visibile area
if(isIn)
isIn=_inVisibleAreaMap[y*_width+x];
if(isIn)
Log.d("DEBUG","in");
else Log.d("DEBUG","out");
return true;
}
});
}
private static void runJustBeforeBeingDrawn(final View view,final Runnable runnable)
{
final ViewTreeObserver vto=view.getViewTreeObserver();
final OnPreDrawListener preDrawListener=new OnPreDrawListener()
{
@Override
public boolean onPreDraw()
{
runnable.run();
final ViewTreeObserver vto=view.getViewTreeObserver();
vto.removeOnPreDrawListener(this);
return true;
}
};
vto.addOnPreDrawListener(preDrawListener);
}
}
在情况下的ImageView已设置其宽度和放大器;高度WRAP_CONTENT，它真的有需要，才可以使用大小阿德南·扎希德解决方案，这可能是这样写的：
in case the imageView has set its width&height to wrap_content, and it really got the size it needs, only then you can use Adnan Zahid solution, which could be written this way:
public class MainActivity extends Activity
{
private int _width,_height;
@Override
protected void onCreate(final Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final ImageView image=(ImageView)findViewById(R.id.imageView1);
final Bitmap bitmap=((BitmapDrawable)image.getDrawable()).getBitmap();
_width=bitmap.getWidth();
_height=bitmap.getHeight();
image.setOnTouchListener(new OnTouchListener()
{
@Override
public boolean onTouch(final View v,final MotionEvent event)
{
final int x=(int)event.getX(),y=(int)event.getY();
boolean isIn=x>=0&&y>=0&&x<_width&&y<_height;
if(isIn)
{
final int pixel=bitmap.getPixel((int)event.getX(),(int)event.getY());
final int alphaValue=Color.alpha(pixel);
isIn=alphaValue!=0;
}
if(isIn)
Log.d("DEBUG","in");
else Log.d("DEBUG","out");
return true;
}
});
}
}
这篇关于按钮的真实自定形状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！