• 项目中为了实现账号多设备登录的监听 一个账号在别的设备登录时在该设备上需要弹出对话框提示 故而用到全局对话框

实现方式

• [ 1 ]. 添加权限

 <!--全局弹窗的权限-->
    <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />

• [ 2 ]. 设置dialog类型

一定要在show之前设置
如果类型为TYPE_SYSTEM_ALERT需要开启悬浮窗权限 使用相当不方便
因此使用TYPE_TOAST 一般设备不需要特意去开启权限即可使用

//设置弹出全局对话框
        dialog.getWindow().setType(WindowManager.LayoutParams.TYPE_TOAST);
//dialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
        dialog.show();

• [ 3 ]. 完整代码

public static void showDialog(final Context context, final String title, final Boolean isCancelable, final String ok, final String close, final DialogCallback callback) {

        AlertDialog.Builder builder = new AlertDialog.Builder(context);
        /*true 代表点击空白可消失   false代表点击空白哦不可消失 */
        builder.setCancelable(isCancelable);
        View view = View.inflate(context, R.layout.item_dialog_exit, null);
        TextView tv_itemdialog_title = (TextView) view.findViewById(R.id.tv_itemdialog_title);
        TextView tv_itemdialog_ok = (TextView) view.findViewById(R.id.tv_itemdialog_ok);
        TextView tv_itemdialog_close = (TextView) view.findViewById(R.id.tv_itemdialog_close);

        tv_itemdialog_ok.setText(ok);
        tv_itemdialog_close.setText(close);

        builder.setView(view);
        final AlertDialog dialog = builder.create();
        //设置弹出全局对话框
        dialog.getWindow().setType(WindowManager.LayoutParams.TYPE_TOAST);
        dialog.show();

        tv_itemdialog_title.setText(title);
        tv_itemdialog_ok.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                callback.onPositive(dialog);
            }
        });

        tv_itemdialog_close.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                callback.onNegative(dialog);
            }
        });

使用WindowManager实现全局对话框

/**
     * 显示弹出框
     *
     * @param context
     */
    public static void showPopupWindow(final Context context, final DialogCallback callback) {
        // 获取WindowManager
        final WindowManager mWindowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);


        final WindowManager.LayoutParams params = new WindowManager.LayoutParams();
        // 类型
        params.type = WindowManager.LayoutParams.TYPE_SYSTEM_ALERT;
        // 设置flag
        params.flags = WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM | 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
        // 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 = WindowManager.LayoutParams.WRAP_CONTENT;
        params.height = WindowManager.LayoutParams.WRAP_CONTENT;
        params.gravity = Gravity.CENTER;
        TextView textView = new TextView(context);
        textView.setText("sfgsfdsfbsadfbasdfg");
        textView.setTextSize(100);

        final View mView = LayoutInflater.from(context).inflate(R.layout.item_dialog_exit, null);
        TextView tv_itemdialog_title = (TextView) mView.findViewById(R.id.tv_itemdialog_title);
        TextView tv_itemdialog_ok = (TextView) mView.findViewById(R.id.tv_itemdialog_ok);
        TextView tv_itemdialog_close = (TextView) mView.findViewById(R.id.tv_itemdialog_close);

        tv_itemdialog_ok.setText("重新登录");
        tv_itemdialog_close.setText("退出登录");
        tv_itemdialog_title.setText("该账户在其他设备登录,若不是您在操作,请及时修改密码以防泄露信息");
        tv_itemdialog_ok.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // 隐藏弹窗
                mWindowManager.removeView(mView);
                callback.onPositive();
            }
        });

        tv_itemdialog_close.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mWindowManager.removeView(mView);
                callback.onNegative();
            }
        });

        mWindowManager.addView(textView, params);
    }