onclicklistener

问题 I am confused: why with inline onlick, we have to write onclick="hello()", but in JS, we should write btn.onclick=hello or btn.addEventListener('click',hello); for regular function, why with inline onlick, "this" refers to window, but with js call, "this" refers to button. I don't understand last two buttons according to w3school, In a function, this refers to the global object. https://www.w3schools.com/js/js_this.asp In regular functions the this keyword represented the object that called

问题 I have 4 images as buttons and when the correct button is selected, an arrow button appears which is working fine. My problem is that I'm trying to change the background resource of each button to change when this arrow is clicked but I'm getting a null pointer exception at this line : happybutton.setBackgroundResource(R.drawable.mum1); I have declared the nextArrow button in my java onCreate - nextArrow = (Button) findViewById(R.id.nextArrow); nextArrow.setOnClickListener(onClickListener);

问题 I want my code to start when I click left mouse button but my code starts right after I click on button. How to make my code wait for mouse input before continue? I already tried input() but it's not what I'm looking for. from tkinter import * import PIL.ImageGrab from PIL import ImageGrab import time import numpy as np import pyautogui import win32api def mouseposition(): global xclick global yclick xclick, yclick = win32api.GetCursorPos() print(xclick, yclick) def mouseclick(): state_left =

问题 I want my code to start when I click left mouse button but my code starts right after I click on button. How to make my code wait for mouse input before continue? I already tried input() but it's not what I'm looking for. from tkinter import * import PIL.ImageGrab from PIL import ImageGrab import time import numpy as np import pyautogui import win32api def mouseposition(): global xclick global yclick xclick, yclick = win32api.GetCursorPos() print(xclick, yclick) def mouseclick(): state_left =

问题 Getting errors on, sorry only beginner. All help would be great. 05-31 21:49:16.077: E/AndroidRuntime(655): FATAL EXCEPTION: main 05-31 21:49:16.077: E/AndroidRuntime(655): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.appal.song/com.appal.song.MainActivity}: java.lang.NullPointerException 05-31 21:49:16.077: E/AndroidRuntime(655): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956) 05-31 21:49:16.077: E/AndroidRuntime(655): at android.app

问题 This question already has answers here : jQuery .on function for future elements, as .live is deprecated [duplicate] (2 answers) Closed 7 years ago . As far as I know, the click() method isn't working for me because the element I'm clicking does not exist on page load (DOM ready). I've found many answers suggesting to use .live('click',function(){...}) . This works great! However, .live() is depreciated as of jQuery 1.7 So, I've tried using .on('click',function(){...}) instead, but it doesn't

问题 This question already has answers here : jQuery .on function for future elements, as .live is deprecated [duplicate] (2 answers) Closed 7 years ago . As far as I know, the click() method isn't working for me because the element I'm clicking does not exist on page load (DOM ready). I've found many answers suggesting to use .live('click',function(){...}) . This works great! However, .live() is depreciated as of jQuery 1.7 So, I've tried using .on('click',function(){...}) instead, but it doesn't

问题 This question already has answers here : jQuery .on function for future elements, as .live is deprecated [duplicate] (2 answers) Closed 7 years ago . As far as I know, the click() method isn't working for me because the element I'm clicking does not exist on page load (DOM ready). I've found many answers suggesting to use .live('click',function(){...}) . This works great! However, .live() is depreciated as of jQuery 1.7 So, I've tried using .on('click',function(){...}) instead, but it doesn't

问题 Im following this link answer--> https://stackoverflow.com/a/32323801/12553303 ...on click of item im getting an error of invalid product id...but how do i get id from adapter to activity??????? i have used interface for click listener... need help in here --> RetrofitClient.instance.deletecart(token, dataList?.get(position)?.product_id.toString()) on debuuging this line following is my code :-- class CartAdapter(private val context: Context, private val dataList: MutableList<DataCart?>?) :

来源： https://stackoverflow.com/questions/61345198/motionlayout-prevents-clicklistener-on-all-views