场景描述：
界面上有一个浮动按钮，可以用手指拖动，点击该按钮触发事件，我这里是启动扫描，留了一个空实现。
private WindowManager wm;
private View view;// 浮动按钮
/**
* 添加悬浮View
* @param paddingBottom 悬浮View与屏幕底部的距离
*/
protected void createFloatView(int paddingBottom) {
int w = 200;// 大小
wm = (WindowManager) getSystemService(Context.WINDOW_SERVICE);
view = getLayoutInflater().inflate(R.layout.floatview, null);
final WindowManager.LayoutParams params = new WindowManager.LayoutParams();
params.type = LayoutParams.TYPE_BASE_APPLICATION;// 所有程序窗口的“基地”窗口，其他应用程序窗口都显示在它上面。
params.flags = LayoutParams.FLAG_NOT_TOUCH_MODAL
| LayoutParams.FLAG_NOT_FOCUSABLE;
params.format = PixelFormat.TRANSLUCENT;// 不设置这个弹出框的透明遮罩显示为黑色
params.width = w;
params.height = w;
params.gravity = Gravity.TOP | Gravity.LEFT;
int screenWidth = getResources().getDisplayMetrics().widthPixels;
int screenHeight = getResources().getDisplayMetrics().heightPixels;
params.x = screenWidth - w;
params.y = screenHeight - w - paddingBottom;
view.setBackgroundColor(Color.TRANSPARENT);
view.setVisibility(View.VISIBLE);
view.setOnTouchListener(new OnTouchListener() {
// 触屏监听
float lastX, lastY;
int oldOffsetX, oldOffsetY;
int tag = 0;// 悬浮球 所需成员变量
@Override
public boolean onTouch(View v, MotionEvent event) {
final int action = event.getAction();
float x = event.getX();
float y = event.getY();
if (tag == 0) {
oldOffsetX = params.x; // 偏移量
oldOffsetY = params.y; // 偏移量
}
if (action == MotionEvent.ACTION_DOWN) {
lastX = x;
lastY = y;
} else if (action == MotionEvent.ACTION_MOVE) {
params.x += (int) (x - lastX) / 3; // 减小偏移量,防止过度抖动
params.y += (int) (y - lastY) / 3; // 减小偏移量,防止过度抖动
tag = 1;
wm.updateViewLayout(view, params);
} else if (action == MotionEvent.ACTION_UP) {
int newOffsetX = params.x;
int newOffsetY = params.y;
// 只要按钮一动位置不是很大,就认为是点击事件
if (Math.abs(oldOffsetX - newOffsetX) <= 20
&& Math.abs(oldOffsetY - newOffsetY) <= 20) {
onFloatViewClick();
} else {
tag = 0;
}
}
return true;
}
});
wm.addView(view, params);
}
/**
* 点击浮动按钮触发事件，需要override该方法
*/
protected void onFloatViewClick() {
}
/**
* 将悬浮View从WindowManager中移除，需要与createFloatView()成对出现
*/
protected void removeFloatView() {
if (wm != null && view != null) {
wm.removeViewImmediate(view);
// wm.removeView(view);//不要调用这个，WindowLeaked
view = null;
wm = null;
}
}
/**
* 隐藏悬浮View
*/
protected void hideFloatView() {
if (wm != null && view != null&&view.isShown()) {
view.setVisibility(View.GONE);
}
}
/**
* 显示悬浮View
*/
protected void showFloatView(){
if (wm != null && view != null&&!view.isShown()) {
view.setVisibility(View.VISIBLE);
}
}
import com.mobovip.bgr.R;
import android.content.Context;
import android.graphics.PixelFormat;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.Gravity;
import android.view.MotionEvent;
import android.view.WindowManager;
import android.view.WindowManager.LayoutParams;
import android.widget.ImageView;
/**
* @author manymore13
* @Blog <a
* href="javascript:void(0)">javascript:void(0)
* </a>
* @version 1.0 floatView = new FloatView(this); // 创建窗体
* floatView.setOnClickListener(this); //
* 设置事件，你需要实现FloatView里的onclick接口 floatView.show(); // 显示该窗体
* floatView.hide(); // 隐藏窗体
*/
public class FloatView extends ImageView {
private Context c;
private float mTouchX;
private float mTouchY;
private float x;
private float y;
private int startX;
private int startY;
private int imgId = R.drawable.ic_launcher;
private int controlledSpace = 20;
private int screenWidth;
private int screenHeight;
boolean isShow = false;
private OnClickListener mClickListener;
private WindowManager windowManager;
private WindowManager.LayoutParams windowManagerParams = new WindowManager.LayoutParams();
public FloatView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public FloatView(Context c) {
super(c);
initView(c);
}
// 初始化窗体
public void initView(Context c) {
windowManager = (WindowManager) c.getApplicationContext()
.getSystemService(Context.WINDOW_SERVICE);
DisplayMetrics dm=getResources().getDisplayMetrics();
screenWidth = dm.widthPixels;
screenHeight = dm.heightPixels;
this.setImageResource(imgId);
windowManagerParams.type = LayoutParams.TYPE_PHONE;
windowManagerParams.format = PixelFormat.RGBA_8888; // 背景透明
windowManagerParams.flags = LayoutParams.FLAG_NOT_TOUCH_MODAL
| LayoutParams.FLAG_NOT_FOCUSABLE;
// 调整悬浮窗口至左上角，便于调整坐标
windowManagerParams.gravity = Gravity.LEFT | Gravity.TOP;
// 以屏幕左上角为原点，设置x、y初始值
windowManagerParams.x = 0;
windowManagerParams.y = screenHeight>>1;
// 设置悬浮窗口长宽数据
windowManagerParams.width = LayoutParams.WRAP_CONTENT;
windowManagerParams.height = LayoutParams.WRAP_CONTENT;
}
public void setImgResource(int id) {
imgId = id;
}
@Override
public boolean onTouchEvent(MotionEvent event) {
x = event.getRawX();
y = event.getRawY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN: {
mTouchX = event.getX();
mTouchY = event.getY();
startX = (int) event.getRawX();
startY = (int) event.getRawY();
break;
}
case MotionEvent.ACTION_MOVE: {
updateViewPosition();
break;
}
case MotionEvent.ACTION_UP: {
if (Math.abs(x - startX) < controlledSpace
&& Math.abs(y - startY) < controlledSpace) {
if (mClickListener != null) {
mClickListener.onClick(this);
}
}
// Log.i("tag", "x=" + x + " startX+" + startX + " y=" + y
// + " startY=" + startY);
if (x <= screenWidth / 2) {
x = 0;
} else {
x = screenWidth;
}
updateViewPosition();
break;
}
}
return super.onTouchEvent(event);
}
// 隐藏该窗体
public void hide() {
if (isShow) {
windowManager.removeView(this);
isShow = false;
}
}
// 显示该窗体
public void show() {
if (isShow == false) {
windowManager.addView(this, windowManagerParams);
isShow = true;
}
}
@Override
public void setOnClickListener(OnClickListener l) {
this.mClickListener = l;
}
private void updateViewPosition() {
// 更新浮动窗口位置参数
windowManagerParams.x = (int) (x - mTouchX);
windowManagerParams.y = (int) (y - mTouchY);
windowManager.updateViewLayout(this, windowManagerParams); // 刷新显示
}
}
一个Android布局可以拖动排序子控件：RearrangeableLayout
https://github.com/rajasharan/RearrangeableLayout
