本文实例为大家分享了android自定义View圆圈拖动的具体代码，供大家参考，具体内容如下
问题：
1 . 累加问题：“点击坐标”坐标在移动时必须改变位置，不然将导致累加过载
2. 圆形改变问题，每次刷新时圆必将改变位置
3. 图片平移：圆在移动时只要
public class MovingBlockView extends View {
//画笔
Paint paint = new Paint();
Region circleRegion;
Path circlePath;
private boolean Move;
private float x = 300;
private float y = 300;
private float ClickX = 0;
private float ClickY = 0;
private float moveX;
private float moveY;
public MovingBlockView(Context context) {
this(context, null);
}
public MovingBlockView(Context context, @Nullable AttributeSet attrs) {
this(context, attrs, 0);
}
public MovingBlockView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
paint.setColor(Color.RED);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
circlePath = new Path();
x = x + moveX;
y = y + moveY;
circlePath.addCircle(x, y, 300, Path.Direction.CW);
Region region = new Region(0, 0, getMeasuredWidth(), getMeasuredHeight());
circleRegion = new Region();
circleRegion.setPath(circlePath, region);
canvas.drawPath(circlePath, paint);
canvas.drawLine(x + moveX, 0, x + moveX, getHeight(), paint);
canvas.drawLine(0, y + moveY, getWidth(), y + moveY, paint);
// canvas.drawCircle();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
int action = event.getAction();
if (action == MotionEvent.ACTION_DOWN) {
boolean contains = circleRegion.contains((int) event.getX(), (int) event.getY());
if (contains) {
// Toast.makeText(getContext(), "点击了圆", Toast.LENGTH_LONG).show();
Move = true;
ClickX = event.getX();
ClickY = event.getY();
Log.d(TAG, "ACTION_DOWN: " + ClickX);
Log.d(TAG, "ACTION_DOWN: " + ClickY);
}
} else if (action == MotionEvent.ACTION_UP) {
x = x + moveX;
y = y + moveY;
Move = false;
Log.d(TAG, "ACTION_UP: ");
} else if (action == MotionEvent.ACTION_MOVE) {
if (Move) {
Log.d(TAG, "ACTION_MOVE: ");
moveX = event.getX() - ClickX;
moveY = event.getY() - ClickY;
ClickX = event.getX();
ClickY = event.getY();
Log.d(TAG, "ACTION_MOVE: " + moveX);
Log.d(TAG, "ACTION_MOVE: " + moveY);
invalidate();
}
}
return super.onTouchEvent(event);
}
}小编再为大家分享一段之前收藏的代码：android自定义view圆形可移动
public class Mycircle2 extends View {
private Paint paint;
private int rawX;
private int rawY;
private int wid;
private int he;
int statusBarHeight1 = -1;
//构造方法，一般会重写三个
//用于初始化一些数据，或者其他东西
public Mycircle2(Context context) {
this(context,null);
}
public Mycircle2(Context context, @Nullable AttributeSet attrs) {
this(context, attrs,0);
}
public Mycircle2(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
//初始化画笔
//抗锯齿
paint = new Paint(Paint.ANTI_ALIAS_FLAG);
//设置画笔
paint.setColor(Color.GREEN);//设置画笔颜色
paint.setStrokeWidth(3);//设置画笔粗细
//获取整个屏幕的高度和宽度
DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
wid = displayMetrics.widthPixels;
he = displayMetrics.heightPixels;
//获取status_bar_height资源的ID 获取状态栏的高度
int resourceId = getResources().getIdentifier("status_bar_height", "dimen", "android");
if (resourceId > 0) {
//根据资源ID获取响应的尺寸值
statusBarHeight1 = getResources().getDimensionPixelSize(resourceId);
}
}
//重写绘制的方法
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawCircle(50,50,50,paint);
}
//拖动事件
//拖动的实现原理：
// onTouchEvent 处理触摸事件
//Touch事件：1.按下ACTION_DOWN，2.抬起ACTION_UP，3 滑动 ACTION_MOVE 4.取消ACTION_CANCEL
//获取触摸点的坐标
//绝对坐标---相对于屏幕来说
//相对坐标---相对于自己
//event.getAction() 获取事件
@Override
public boolean onTouchEvent(MotionEvent event) {
super.onTouchEvent(event);
switch (event.getAction()){
case MotionEvent.ACTION_DOWN:
//获取开始的坐标
rawX = (int) event.getRawX();
rawY = (int) event.getRawY();
break;
case MotionEvent.ACTION_MOVE:
//获取移动时候的坐标
int yX = (int) event.getRawX();
int yY = (int) event.getRawY();
//减去手指按下时候的坐标
//得到移动的间距
int jX=yX-rawX;
int jY=yY-rawY;
//将间距，加到原来的坐标（上下左右）
int l=getLeft()+jX;
int r=getRight()+jX;
int t=getTop()+jY;
int b=getBottom()+jY;
//判断
if(l<0){
l=0;
r=getWidth();
}
if(t<0){
t=0;
b=getHeight();
}
if(r>wid){
r=wid;
l=wid-getHeight();
}
//如果移动到最下边,就判断是否等于屏幕高度减去状态栏高度
if(b>he-statusBarHeight1){
//赋值
b=he-statusBarHeight1;
t=b-getHeight();
}
//重新赋值给布局
layout(l,t,r,b);//规定了View的位置
//将lastX，lastY重新赋值
rawX=yX;
rawY=yY;
break;
case MotionEvent.ACTION_UP:
break;
}
return true;//返回true代表自己处理事件
}
}以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持编程网。
