我想做一个简单的控件:一个里面有视图的容器。如果我触摸容器并移动手指,我想让视图跟着我的手指移动。
我应该使用什么样的容器(布局)?如何做到这一点?
我不需要使用一个表面,但一个简单的布局。
我想做一个简单的控件:一个里面有视图的容器。如果我触摸容器并移动手指,我想让视图跟着我的手指移动。
我应该使用什么样的容器(布局)?如何做到这一点?
我不需要使用一个表面,但一个简单的布局。
当前回答
和@Alex Karshin的答案一样,我做了一点改变。
public class MovingObject implements OnTouchListener {
private RelativeLayout.LayoutParams lParams;
private PointF viewPoint, prePoint, currPoint;
public MovingObject() {
lParams = null;
viewPoint = new PointF();
prePoint = new PointF();
currPoint = new PointF();
}
public boolean onTouch(View view, MotionEvent event) {
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
viewPoint.set(view.getX(), view.getY());
prePoint.set(event.getRawX(), event.getRawY());
lParams = (RelativeLayout.LayoutParams) view.getLayoutParams();
break;
case MotionEvent.ACTION_UP:
break;
case MotionEvent.ACTION_POINTER_DOWN:
break;
case MotionEvent.ACTION_POINTER_UP:
break;
case MotionEvent.ACTION_MOVE:
currPoint.set(event.getRawX(), event.getRawY());
moveToCurrentPoint(view);
break;
}
view.invalidate();
return true;
}
private void moveToCurrentPoint(View view) {
float dx = currPoint.x - prePoint.x - prePoint.x + viewPoint.x;
float dy = currPoint.y - prePoint.y - prePoint.y + viewPoint.y;
lParams.leftMargin = (int) (prePoint.x + dx);
lParams.topMargin = (int) (prePoint.y + dy);
view.setLayoutParams(lParams);
}
}
其他回答
按照@Andrew方法,如果你想要移动视图的中心,你只需要减去视图的一半高度和一半宽度。
float dX, dY;
@Override
public boolean onTouchEvent(View view, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
dX = view.getX() - event.getRawX();
dY = view.getY() - event.getRawY();
break;
case MotionEvent.ACTION_MOVE:
view.animate()
.x(event.getRawX() + dX - (view.getWidth() / 2f))
.y(event.getRawY() + dY - (view.getHeight() / 2f))
.setDuration(0)
.start();
break;
default:
return false;
}
return true;
}
kotlin的简单代码:
var dx = 0f
var dy = 0f
private fun setMyViewListener(): OnTouchListener {
return OnTouchListener { view, event ->
when (event.action) {
MotionEvent.ACTION_DOWN -> {
dx = view.x - event.rawX
dx = view.y - event.rawY
}
MotionEvent.ACTION_MOVE -> view.animate()
.x(event.rawX + dx)
//.y(event.rawY + dy) // uncomment this line to move y
.setDuration(0)
.start()
}
true
}
}
然后像这样调用它:
var myView = findViewById<ConstraintLayout>(R.id.myView)
myView.setOnTouchListener(setMyViewListener())
改变了一点由@Vyacheslav Shylkin提供的解决方案,以删除手动输入数字的依赖性。
import android.app.Activity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewTreeObserver;
import android.widget.ImageView;
import android.widget.RelativeLayout;
public class MainActivity extends Activity implements View.OnTouchListener
{
private int _xDelta;
private int _yDelta;
private int _rightMargin;
private int _bottomMargin;
private ImageView _floatingView;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
this._floatingView = (ImageView) findViewById(R.id.textView);
this._floatingView.getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener()
{
@Override
public boolean onPreDraw()
{
if (_floatingView.getViewTreeObserver().isAlive())
_floatingView.getViewTreeObserver().removeOnPreDrawListener(this);
updateLayoutParams(_floatingView);
return false;
}
});
this._floatingView.setOnTouchListener(this);
}
private void updateLayoutParams(View view)
{
this._rightMargin = -view.getMeasuredWidth();
this._bottomMargin = -view.getMeasuredHeight();
RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(view.getMeasuredWidth(), view.getMeasuredHeight());
layoutParams.bottomMargin = this._bottomMargin;
layoutParams.rightMargin = this._rightMargin;
view.setLayoutParams(layoutParams);
}
@Override
public boolean onTouch(View view, MotionEvent event)
{
if (view == this._floatingView)
{
final int X = (int) event.getRawX();
final int Y = (int) event.getRawY();
switch (event.getAction() & MotionEvent.ACTION_MASK)
{
case MotionEvent.ACTION_DOWN:
RelativeLayout.LayoutParams lParams = (RelativeLayout.LayoutParams) view.getLayoutParams();
this._xDelta = X - lParams.leftMargin;
this._yDelta = Y - lParams.topMargin;
break;
case MotionEvent.ACTION_MOVE:
RelativeLayout.LayoutParams layoutParams = (RelativeLayout.LayoutParams) view.getLayoutParams();
layoutParams.leftMargin = X - this._xDelta;
layoutParams.topMargin = Y - this._yDelta;
layoutParams.rightMargin = this._rightMargin;
layoutParams.bottomMargin = this._bottomMargin;
view.setLayoutParams(layoutParams);
break;
}
return true;
}
else
{
return false;
}
}
}
//如果你想移动你的相机或任何东西,然后按照下面的方法来做 //我在相机上实现的情况下,你可以应用它在任何你想要的
public class VideoCallActivity extends AppCompatActivity implements
View.OnTouchListener {
FrameLayout myLayout1;
@SuppressLint("ClickableViewAccessibility")
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//in the frame layout I am setting my camera
myLayout1.setOnTouchListener(this);
}
float dX, dY;
@Override
public boolean onTouch(View view, MotionEvent event) {
switch (event.getAction()) {
//this is your code
case MotionEvent.ACTION_DOWN:
dX = view.getX() - event.getRawX();
dY = view.getY() - event.getRawY();
break;
case MotionEvent.ACTION_MOVE:
view.animate()
.x(event.getRawX() + dX)
.y(event.getRawY() + dY)
.setDuration(0)
.start();
break;
default:
return false;
}
return true;
}
在Kotlin中实现相同
rightPanel.setOnTouchListener(View.OnTouchListener { view, event ->
when (event?.action) {
MotionEvent.ACTION_DOWN -> {
rightDX = view!!.x - event.rawX
// rightDY = view!!.getY() - event.rawY;
}
MotionEvent.ACTION_MOVE -> {
var displacement = event.rawX + rightDX
view!!.animate()
.x(displacement)
// .y(event.getRawY() + rightDY)
.setDuration(0)
.start()
}
else -> { // Note the block
return@OnTouchListener false
}
}
true
})