Android实现自由拖动并显示文字的悬浮框

项目中需要实现一个状态显示的悬浮框，要求可以设置两种模式：拖动模式和不可拖动模式。

实现效果图如下：

实现步骤：

1.首先要设置该悬浮框的基本属性：

/**
* 显示弹出框
*
* @param context
*/
@SuppressWarnings("WrongConstant")
public static void showPopupWindow(final Context context, String showtxt) {
if (isShown) {
 return;
}
isShown = true;
// 获取WindowManager
mWindowManager = (WindowManager) context
 .getSystemService(Context.WINDOW_SERVICE);
mView = setUpView(context, showtxt);

params = new WindowManager.LayoutParams();
// 类型，系统提示以及它总是出现在应用程序窗口之上。
params.type = WindowManager.LayoutParams.TYPE_SYSTEM_ALERT |
 WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY;

// 设置flag
int flags = canTouchFlags;

// | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE;
// 如果设置了WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE，弹出的View收不到Back键的事件
params.flags = flags;
// 不设置这个弹出框的透明遮罩显示为黑色
params.format = PixelFormat.TRANSLUCENT;
// FLAG_NOT_TOUCH_MODAL不阻塞事件传递到后面的窗口
// 设置 FLAG_NOT_FOCUSABLE 悬浮窗口较小时，后面的应用图标由不可长按变为可长按
// 不设置这个flag的话，home页的划屏会有问题
params.width = LayoutParams.WRAP_CONTENT;
params.height = LayoutParams.WRAP_CONTENT;
params.gravity = Gravity.TOP;
mWindowManager.addView(mView, params);
}

比较重要的点是要注意设置flags，我这里提供了两种flags以供切换：

private static int canTouchFlags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
 | WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL;

private static int notTouchFlags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE|
 WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE;

第一种是可触摸不可聚焦模式，第二种是不可触摸不可聚焦模式。其他的flags可以从api中查阅。

2.设置悬浮框的拖动监听事件：

private static View setUpView(final Context context, String showtxt) {
View view = LayoutInflater.from(context).inflate(R.layout.layout_popwindow,
 null);

TextView showTv = (TextView) view.findViewById(R.id.tv_showinpop);
showTv.setText(showtxt);

rl_drag_showinpop = (RelativeLayout) view.findViewById(R.id.rl_drag_showinpop);
rl_drag_showinpop.setOnTouchListener(new View.OnTouchListener() {
 private float lastX; //上一次位置的X.Y坐标
 private float lastY;
 private float nowX; //当前移动位置的X.Y坐标
 private float nowY;
 private float tranX; //悬浮窗移动位置的相对值
 private float tranY;

@Override
 public boolean onTouch(View v, MotionEvent event) {
 boolean ret = false;
 switch (event.getAction()) {
  case MotionEvent.ACTION_DOWN:

// 获取按下时的X，Y坐标
  lastX = event.getRawX();
  lastY = event.getRawY();
  ret = true;

break;
  case MotionEvent.ACTION_MOVE:
  // 获取移动时的X，Y坐标
  nowX = event.getRawX();
  nowY = event.getRawY();
  // 计算XY坐标偏移量
  tranX = nowX - lastX;
  tranY = nowY - lastY;
  params.x += tranX;
  params.y += tranY;

//更新悬浮窗位置
  mWindowManager.updateViewLayout(mView, params);
  //记录当前坐标作为下一次计算的上一次移动的位置坐标
  lastX = nowX;
  lastY = nowY;

break;
  case MotionEvent.ACTION_UP:
  break;
 }
 return ret;
 }
});

这里要在down的时候记录坐标，move事件中使用修改params坐标进行移动。

3.设置悬浮框文字属性：

public static void setShowTxt(String txt) {
try {
 TextView showTv = (TextView) mView.findViewById(R.id.tv_showinpop);
 showTv.setText(txt);
 mWindowManager.updateViewLayout(mView, params);
}catch (Exception e){
 Log.d(TAG, "setShowTxt: 更新悬浮框错误");
 e.printStackTrace();
 if(e.getMessage().contains("not attached to window manager")){
 mWindowManager.addView(mView, params);
 }
}
}

4.更新悬浮框图片显示：

public static void setShowImg(Bitmap bitmap) {
try {
 ImageView showImg = (ImageView) mView.findViewById(R.id.iv_showinpop);
 showImg.setImageBitmap(bitmap);
 mWindowManager.updateViewLayout(mView, params);
}catch (Exception e){
 Log.d(TAG, "setShowTxt: 更新悬浮框错误");
 e.printStackTrace();
 if(e.getMessage().contains("not attached to window manager")){
 mWindowManager.addView(mView, params);
 }
}
}

介绍完毕，整个类都封装好了，代码如下：

/**
* 悬浮窗工具类
* created by Pumpkin at 17/3/28
*/
public class WindowsUitlity {
private static String TAG = WindowsUitlity.class.getSimpleName();
private static WindowManager mWindowManager = null;
private static WindowManager.LayoutParams params;
public static Boolean isShown = false;
private static View mView = null;

/**
* 显示弹出框
*
* @param context
*/
@SuppressWarnings("WrongConstant")
public static void showPopupWindow(final Context context, String showtxt) {
if (isShown) {
 return;
}
isShown = true;
// 获取WindowManager
mWindowManager = (WindowManager) context
 .getSystemService(Context.WINDOW_SERVICE);
mView = setUpView(context, showtxt);

params = new WindowManager.LayoutParams();
// 类型，系统提示以及它总是出现在应用程序窗口之上。
params.type = WindowManager.LayoutParams.TYPE_SYSTEM_ALERT |
 WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY;

// 设置flag
int flags = canTouchFlags;

// | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE;
// 如果设置了WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE，弹出的View收不到Back键的事件
params.flags = flags;
// 不设置这个弹出框的透明遮罩显示为黑色
params.format = PixelFormat.TRANSLUCENT;
// FLAG_NOT_TOUCH_MODAL不阻塞事件传递到后面的窗口
// 设置 FLAG_NOT_FOCUSABLE 悬浮窗口较小时，后面的应用图标由不可长按变为可长按
// 不设置这个flag的话，home页的划屏会有问题
params.width = LayoutParams.WRAP_CONTENT;
params.height = LayoutParams.WRAP_CONTENT;
params.gravity = Gravity.TOP;
mWindowManager.addView(mView, params);
}

private static int canTouchFlags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
 | WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL;

private static int notTouchFlags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE|
 WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE;

/**
* 设置是否可响应点击事件
*
* @param isTouchable
*/
public static void setTouchable(boolean isTouchable) {
if (isTouchable) {
 params.flags = canTouchFlags;
} else {
 params.flags = notTouchFlags;
}
mWindowManager.updateViewLayout(mView, params);

}

/**
* 隐藏弹出框
*/
public static void hidePopupWindow() {
if (isShown && null != mView) {
 mWindowManager.removeView(mView);
 isShown = false;
}
}

public static void setShowTxt(String txt) {
try {
 TextView showTv = (TextView) mView.findViewById(R.id.tv_showinpop);
 showTv.setText(txt);
 mWindowManager.updateViewLayout(mView, params);
}catch (Exception e){
 Log.d(TAG, "setShowTxt: 更新悬浮框错误");
 e.printStackTrace();
 if(e.getMessage().contains("not attached to window manager")){
 mWindowManager.addView(mView, params);
 }
}
}

public static void setShowImg(Bitmap bitmap) {
try {
 ImageView showImg = (ImageView) mView.findViewById(R.id.iv_showinpop);
 showImg.setImageBitmap(bitmap);
 mWindowManager.updateViewLayout(mView, params);
}catch (Exception e){
 Log.d(TAG, "setShowTxt: 更新悬浮框错误");
 e.printStackTrace();
 if(e.getMessage().contains("not attached to window manager")){
 mWindowManager.addView(mView, params);
 }
}
}

static RelativeLayout rl_drag_showinpop;

private static View setUpView(final Context context, String showtxt) {
View view = LayoutInflater.from(context).inflate(R.layout.layout_popwindow,
 null);

TextView showTv = (TextView) view.findViewById(R.id.tv_showinpop);
showTv.setText(showtxt);

rl_drag_showinpop = (RelativeLayout) view.findViewById(R.id.rl_drag_showinpop);
rl_drag_showinpop.setOnTouchListener(new View.OnTouchListener() {
 private float lastX; //上一次位置的X.Y坐标
 private float lastY;
 private float nowX; //当前移动位置的X.Y坐标
 private float nowY;
 private float tranX; //悬浮窗移动位置的相对值
 private float tranY;

@Override
 public boolean onTouch(View v, MotionEvent event) {
 boolean ret = false;
 switch (event.getAction()) {
  case MotionEvent.ACTION_DOWN:

// 获取按下时的X，Y坐标
  lastX = event.getRawX();
  lastY = event.getRawY();
  ret = true;

break;
  case MotionEvent.ACTION_MOVE:
  // 获取移动时的X，Y坐标
  nowX = event.getRawX();
  nowY = event.getRawY();
  // 计算XY坐标偏移量
  tranX = nowX - lastX;
  tranY = nowY - lastY;
  params.x += tranX;
  params.y += tranY;

//更新悬浮窗位置
  mWindowManager.updateViewLayout(mView, params);
  //记录当前坐标作为下一次计算的上一次移动的位置坐标
  lastX = nowX;
  lastY = nowY;

break;
  case MotionEvent.ACTION_UP:
  break;
 }
 return ret;
 }
});

return view;
}
}

来源：https://pumpkin.blog.csdn.net/article/details/71155781