我希望在所有运动项目之后都有一个 add 按钮：
Image of the RecyclerView I want
我尝试在我的CustomAdapter中实现它，如下所示：
class CustomAdapterExercise(val exerciseList: ArrayList<Exercise>) : RecyclerView.Adapter<CustomAdapterExercise.ViewHolder>() {
val typeAdd = 0
val typeExercise = 1
//this method is returning the view for each item in the list
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CustomAdapterExercise.ViewHolder {
if (viewType == typeAdd) {
val itemView = LayoutInflater.from(parent.context).inflate(R.layout.exercise_layout, parent, false)
return ViewHolder(itemView)
} else if (viewType == typeExercise) {
val itemView = LayoutInflater.from(parent.context).inflate(R.layout.add_layout, parent, false)
return ViewHolder(itemView)
}
else{
val itemView = LayoutInflater.from(parent.context).inflate(R.layout.add_layout, parent, false)
return ViewHolder(itemView)
}
}
//this method is binding the data on the list
override fun onBindViewHolder(holder: CustomAdapterExercise.ViewHolder, position: Int) {
holder.bindItems(exerciseList[position])
}
override fun getItemViewType(position: Int): Int {
if (position <= exerciseList.size) {
return typeExercise
} else if (position == exerciseList.size + 1) {
return typeAdd
}
else{
return typeAdd
}
}
//this method is giving the size of the list
override fun getItemCount(): Int {
return exerciseList.size + 1
}
//the class is hodling the list view
class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
fun bindItems(Exercise: Exercise) {
val exerciseAmount = itemView.findViewById<TextView>(R.id.exerciseAmount)
val exerciseName = itemView.findViewById<TextView>(R.id.exerciseName)
val exerciseWeight = itemView.findViewById<TextView>(R.id.exerciseWeight)
val exerciseSets = itemView.findViewById<TextView>(R.id.exerciseSets)
exerciseAmount.text = Exercise.exAmount
exerciseName.text = Exercise.exName
exerciseWeight.text = Exercise.weight
exerciseSets.text = Exercise.sets
}
}
}
但是一旦我转到那个视图就崩溃了，它给了我这个错误：
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference
at abyte.fitness.fitnessbyte.CustomAdapterExercise$ViewHolder.bindItems(CustomAdapterExercise.kt:67)
我知道这是因为我正在为我的添加按钮分配文本，但我不知道如何以不同方式执行此操作并使其正常工作。
我在整天搜索时已经看到了“重复”的问题，但对于像我这样的初学者来说却没有得到很好的解释......
答案 0 :(得分：0)
您需要在 <?php
$array = array(
array(
array(
'blog_title' => 'sooraj bloging',
'blog_id' => 2
),
array(
'blog_title' => 'What are Mobile App Testing Challenges?',
'blog_id' => 4
),
array(
'blog_title' => 'sooraj blog',
'blog_id' => 8
)
),
array(
array(
'title' => 'sooraj casestudy',
)
),
array(
array(
'career_id' => 14,
'title' => 'Software Engineer .NET sooraj',
'location' => 'Kochi, India.',
'description' => 'Developing .NET applications.',
'qualification' => 'B.Tech. in CSE, MCA',
'status' => 0,
'created_at' => '2017-11-20 13:14:29',
'updated_at' => '0000-00-00 00:00:00'
)
),
array(),
array(
array(
'tst_id' => 146,
'tst_name' => 'John Kasha',
'tst_quote' => 'Gadgeon was extremely professional and was easy to commun sooraj icate and work with on a day-to-day basis. I also liked the fact that they were willing to do the research for specific tasks and present a viable solution or workaround to keep the project on schedule. I would recommend them for any task for any industry software or hardware. Bottom line, they get it done and you get results, not excuses. VP of Engineering.',
'tst_desig' => 'Vice President,Product Development and Engineering',
'tst_image' => '91c09ac9ee6234fdfcc523a393800bd5.jpg',
'url' => '',
'crop_name' => '668959f965ab28815dc97bbc1f8718d8.jpg',
'sysDate' => '2017-11-20 15:42:34'
)
)
);
foreach ($array as $value){
foreach ($value as $row){
foreach ($row as $key=> $row1){
echo $key.' - '. $row1;
}
echo '<br>';
}
}
?>
中启用viewType。
onBindViewHolder旁注：
您使用ViewHolder是错误的方式，每次更新视图时，ViewHolders的好处之一都不会被强制执行override fun onBindViewHolder(holder: CustomAdapterExercise.ViewHolder, position: Int) {
if (holder.itemViewType == typeAdd) {
// Bind the add button
else {
holder.bindItems(exerciseList[position])
}
}
。