所以我想做的就是围绕正在触摸的两个点绘制圆圈,当手指在屏幕上拖动时,让这些圆圈跟随每个手指。
但是,我遇到了一些我无法弄清楚的奇怪行为。因此,当我将两根手指放在屏幕上时,我的圆圈就没有问题了。当我用两根手指拖动时,一切都会按照我想要的方式进行。但是,如果我抬起第一根手指,所有内容都会停止重绘,并且仍在屏幕上的第二根手指将停止被跟踪。如果我把第一个手指放回去,一切都会恢复正常。我想我的两根手指一定处理不好。
有人能看出我做错了什么吗?
此外,如果我有两根手指放在屏幕上,并且抬起并触摸第二根手指,一切都会正常。只有在我有两个手指并且抬起第一个手指的情况下,我才会发现问题。
@Override
public boolean onTouchEvent(MotionEvent event) {
/*
* Log this touch 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("OnTouchEvent 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(TAG, sb.toString());
/*
* Track the touches that are on the screen
* Grab X,Y, and Size data
*/
int action = event.getAction();
int actionCode = action & MotionEvent.ACTION_MASK;
if (actionCode == MotionEvent.ACTION_POINTER_DOWN) {
if (0 == action >> MotionEvent.ACTION_POINTER_ID_SHIFT){
p0Down = true;
}
if (1 == action >> MotionEvent.ACTION_POINTER_ID_SHIFT){
p1Down = true;
}
}
else if (actionCode == MotionEvent.ACTION_POINTER_UP){
if (0 == action >> MotionEvent.ACTION_POINTER_ID_SHIFT){
p0Down = false;
}
if (1 == action >> MotionEvent.ACTION_POINTER_ID_SHIFT){
p1Down = false;
}
}
if(actionCode == MotionEvent.ACTION_DOWN){
if (0 == action >> MotionEvent.ACTION_POINTER_ID_SHIFT){
p0Down = true;
}
if (1 == action >> MotionEvent.ACTION_POINTER_ID_SHIFT){
p1Down = true;
}
}
else if (actionCode == MotionEvent.ACTION_UP){
if (0 == action >> MotionEvent.ACTION_POINTER_ID_SHIFT){
p0Down = false;
}
if (1 == action >> MotionEvent.ACTION_POINTER_ID_SHIFT){
p1Down = false;
}
}
int pointCt = event.getPointerCount();
for(int i = 0; i < pointCt; i++){
int pid = event.getPointerId(i);
if((pid == 0) && p0Down){
curX1 = event.getX(pid);
curY1 = event.getY(pid);
size1 = event.getSize(pid);
}
if((pid == 0) && (p0Down == false)){
curX1 = -1;
curY1 = -1;
size1 = -1;
}
if((pid == 1) && p1Down){
curX2 = event.getX(pid);
curY2 = event.getY(pid);
size2 = event.getSize(pid);
}
if((pid == 1) && (p1Down == false)){
curX2 = -1;
curY2 = -1;
size2 = -1;
}
}
return true;
}
最佳答案
您正在使用指针 ID 作为参数而不是索引来调用 MotionEvent#getX()/getY()/getSize()。
关于android - 多点触控的处理,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/3772736/