无法访问自定义View类中的方法
[英]Cannot access methods inside custom View class
问题描述
我似乎无法访问自定义视图类WorkoutView中实现的任何方法。
我试图以编程方式将这些视图中的几个添加到使用setContentView设置的父布局内的LinearLayout中；
为什么我不能访问WorkoutView类中定义的任何方法？ 我需要访问这些方法，以便可以获取每个单独视图的值（因为可以添加无限多个这些视图）
这是我如何扩大我想与WorkoutView一起使用的布局的方式
inflater = getActivity().getLayoutInflater();
workoutView = (WorkoutView) inflater.inflate(R.layout.single_workout_layout, workoutLayout, false);
这是最初膨胀的父视图中的LinearLayout
workoutLayout = (ViewGroup) view.findViewById(R.id.workoutLayout);
只需将视图添加到trainingLayout
workoutLayout.addView(workoutView);
这是父布局的XML
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.modup.fragment.CreateFragment">
<!-- TODO: Update blank fragment layout -->
<!-- <ScrollView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="@+id/scrollView" android:layout_gravity="center">-->
<com.modup.view.CustomScrollView
android:layout_width="match_parent"
android:id="@+id/scrollView"
android:layout_height="match_parent">
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent" android:id="@+id/scrollViewLinearLayout">
<!-- <android.support.v7.widget.CardView
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:id="@+id/card_view"
android:layout_gravity="center"
card_view:cardElevation="0dp"
android:background="@android:color/white"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>-->
<LinearLayout
android:orientation="vertical"
android:background="@drawable/white_background_shadow"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout
android:orientation="horizontal"
android:layout_margin="10dp"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ImageView
android:id="@+id/imageViewTitle"
android:layout_width="35dp"
android:layout_gravity="center"
android:src="@drawable/title"
android:layout_height="35dp"
/>
<com.wrapp.floatlabelededittext.FloatLabeledEditText
xmlns:float="http://schemas.android.com/apk/res-auto"
android:layout_width="fill_parent"
android:layout_marginRight="10dp"
android:layout_marginLeft="10dp"
android:layout_gravity="center"
android:layout_height="wrap_content"
float:fletPaddingLeft="4dp"
float:fletPaddingBottom="2dp">
<EditText
android:layout_width="fill_parent"
android:maxLength="75"
android:maxLines="3"
android:layout_gravity="center"
android:layout_height="wrap_content"
android:inputType="textMultiLine"
android:ems="10"
android:hint="Title"
android:id="@+id/editText"/>
</com.wrapp.floatlabelededittext.FloatLabeledEditText>
</LinearLayout>
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="1dp" android:layout_gravity="center_horizontal"
android:background="@color/material_grey_500" android:layout_margin="10dp"
android:id="@+id/divider" android:focusableInTouchMode="true">
</LinearLayout>
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout
android:orientation="horizontal"
android:layout_margin="10dp"
android:layout_width="fill_parent"
android:layout_height="wrap_content" android:layout_weight="1">
<ImageView
android:layout_width="36dp"
android:src="@drawable/skull"
android:layout_height="36dp"
android:id="@+id/imageViewDifficulty" android:layout_gravity="center"
android:adjustViewBounds="false"/>
<Spinner
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/spinnerDifficulty" android:layout_gravity="center"/>
</LinearLayout>
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content" android:layout_weight="1"
android:layout_margin="10dp">
<ImageView
android:layout_width="35dp"
android:layout_height="35dp"
android:id="@+id/imageViewTime" android:src="@drawable/stopwatch"
android:layout_gravity="center"/>
<Spinner android:layout_width="fill_parent" android:layout_height="wrap_content"
android:id="@+id/spinnerTime" android:layout_gravity="center"/>
</LinearLayout>
</LinearLayout>
</LinearLayout>
<!-- </android.support.v7.widget.CardView>-->
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content" android:layout_margin="10dp"
>
<Button
android:layout_width="45dp"
android:layout_height="45dp"
android:background="@drawable/add_content_selector"
android:id="@+id/buttonAddWorkout"/>
<com.modup.font.RobotoTextView
android:id="@+id/addWorkout"
style="@style/TextViewAppearance.Title1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:text="Add Workout"
android:textSize="20sp"
android:textColor="@color/primary_blue"
app:typeface="robotoBold" android:layout_weight="1"
android:gravity="center" android:layout_gravity="center" android:adjustViewBounds="false"
android:layout_marginRight="45dp"/>
</LinearLayout>
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent" android:id="@+id/workoutLayout">
</LinearLayout>
</LinearLayout>
</com.modup.view.CustomScrollView>
<Button
android:layout_width="65dp"
android:isScrollContainer="false"
android:layout_height="65dp"
android:layout_margin="25dp"
android:background="@drawable/accept_content_selector"
android:id="@+id/buttonAccept" android:layout_gravity="right|bottom"/>
<Button
android:layout_width="65dp"
android:layout_height="65dp"
android:isScrollContainer="false"
android:layout_marginBottom="25dp"
android:layout_marginRight="100dp"
android:background="@drawable/cancel_content_selector"
android:id="@+id/buttonCancel" android:layout_gravity="right|bottom"/>
</FrameLayout>
这是WorkoutView的XML
<?xml version="1.0" encoding="utf-8"?>
<com.modup.view.WorkoutView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_height="match_parent"
android:id="@+id/workoutView">
<android.support.v7.widget.CardView
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:id="@+id/card_view"
android:layout_gravity="center"
android:layout_width="match_parent"
android:layout_height="wrap_content"
card_view:cardCornerRadius="4dp" android:layout_marginLeft="5dp"
android:layout_marginRight="5dp" android:layout_marginTop="2dp" android:layout_marginBottom="2dp">
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<EditText
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:hint="Enter Workout Name"
android:id="@+id/etWorkoutName" android:layout_margin="5dp" android:layout_weight="1"/>
<Button
android:layout_width="35dp"
android:layout_height="35dp"
android:background="@drawable/cancel_content_selector"
android:id="@+id/btnRemoveWorkout" android:layout_margin="5dp"/>
</LinearLayout>
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent" android:layout_margin="5dp">
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent" android:layout_weight="1">
<com.modup.font.RobotoTextView
android:id="@+id/textViewMuscleGroup"
style="@style/TextViewAppearance.Title1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="@color/primary_blue"
android:text="Muscle Group"
android:textSize="15sp"
app:typeface="robotoBold"
android:orientation="horizontal"
android:gravity="center" android:padding="5dp"/>
<Spinner
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/spinnerWorkoutGroup" android:textAlignment="center"
android:layout_weight="1"/>
</LinearLayout>
</LinearLayout>
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent" android:layout_margin="5dp">
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent" android:layout_weight="1">
<com.modup.font.RobotoTextView
android:id="@+id/textViewSet"
style="@style/TextViewAppearance.Title1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="@color/primary_blue"
android:text="Sets"
android:textSize="15sp"
app:typeface="robotoBold"
android:orientation="horizontal"
android:gravity="center" android:padding="5dp"/>
<Spinner
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/spinnerSets" android:textAlignment="center" android:layout_weight="1"/>
</LinearLayout>
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent" android:layout_weight="1">
<com.modup.font.RobotoTextView
android:id="@+id/textViewRep"
style="@style/TextViewAppearance.Title1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="@color/primary_blue"
android:text="Reps"
android:textSize="15sp"
app:typeface="robotoBold"
android:orientation="horizontal"
android:gravity="center" android:padding="5dp"/>
<Spinner
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/spinnerReps" android:textAlignment="center" android:layout_weight="1"/>
</LinearLayout>
</LinearLayout>
</LinearLayout>
</android.support.v7.widget.CardView>
</com.modup.view.WorkoutView>
这是WorkoutView类
public class WorkoutView extends LinearLayout implements View.OnClickListener {
int res_id;
public Spinner spinnerDifficulty, spinnerTime, spinnerMuscleGroup, spinnerSets, spinnerReps;
public EditText etWorkoutName;
public Button btnRemoveWorkout;
String workoutName, muscleGroup, sets, reps;
LayoutInflater inflater;
public WorkoutView(Context context) {
super(context);
}
public WorkoutView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public WorkoutView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
public void init() {
spinnerDifficulty = (Spinner) findViewById(R.id.spinnerDifficulty);
spinnerReps = (Spinner) findViewById(R.id.spinnerReps);
spinnerSets = (Spinner) findViewById(R.id.spinnerSets);
spinnerMuscleGroup = (Spinner) findViewById(R.id.spinnerWorkoutGroup);
spinnerTime = (Spinner) findViewById(R.id.spinnerTime);
etWorkoutName = (EditText) findViewById(R.id.etWorkoutName);
btnRemoveWorkout = (Button) this.findViewById(R.id.btnRemoveWorkout);
btnRemoveWorkout.setOnClickListener(this);
}
public String getReps() {
reps = spinnerReps.getSelectedItem().toString();
return reps;
}
public String getWorkoutName() {
workoutName = etWorkoutName.getText().toString().trim();
return workoutName;
}
public String getMuscleGroup() {
muscleGroup = spinnerMuscleGroup.getSelectedItem().toString();
return muscleGroup;
}
public String getSets() {
sets = spinnerSets.getSelectedItem().toString();
return sets;
}
public SingleWorkout getAll() {
//to be designed
return null;
}
@Override
public void onClick(View v) {
switch (v.getId()){
case R.id.btnRemoveWorkout:
Log.e("DID THIS WORK?", "BUTTON PRESSED");
break;
}
}
}
编辑：我无法调用WorkoutView中的方法，例如
workoutView.getReps();
结果为NullPointerException
java.lang.NullPointerException
at com.modup.view.WorkoutView.getReps(WorkoutView.java:51)
at com.modup.fragment.CreateFragment.onClick(CreateFragment.java:197)
更新
我添加了init（）; 构造函数的方法，它将导致此错误
03-06 22:48:06.952 22106-22106/com.modup.app E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.modup.app, PID: 22106
android.view.InflateException: Binary XML file line #2: Error inflating class com.modup.view.WorkoutView
at android.view.LayoutInflater.createView(LayoutInflater.java:620)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:696)
at android.view.LayoutInflater.inflate(LayoutInflater.java:469)
at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
at com.modup.fragment.CreateFragment.onClick(CreateFragment.java:195)
at android.view.View.performClick(View.java:4442)
at android.view.View$PerformClick.run(View.java:18473)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5105)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:792)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:608)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Constructor.constructNative(Native Method)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at android.view.LayoutInflater.createView(LayoutInflater.java:594)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:696)
at android.view.LayoutInflater.inflate(LayoutInflater.java:469)
at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
at com.modup.fragment.CreateFragment.onClick(CreateFragment.java:195)
at android.view.View.performClick(View.java:4442)
at android.view.View$PerformClick.run(View.java:18473)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5105)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:792)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:608)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.modup.view.WorkoutView.init(WorkoutView.java:57)
at com.modup.view.WorkoutView.<init>(WorkoutView.java:39)
at java.lang.reflect.Constructor.constructNative(Native Method)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at android.view.LayoutInflater.createView(LayoutInflater.java:594)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:696)
at android.view.LayoutInflater.inflate(LayoutInflater.java:469)
at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
at com.modup.fragment.CreateFragment.onClick(CreateFragment.java:195)
at android.view.View.performClick(View.java:4442)
at android.view.View$PerformClick.run(View.java:18473)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5105)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:792)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:608)
at dalvik.system.NativeStart.main(Native Method)
1 个解决方案
解决方案1
2 已采纳 2015-03-07 03:58:47
我无法在WorkoutView中调用方法……导致NullPointerException
这是因为您期望由findViewById()设置的子视图尚未生效。 在第一种情况下，尝试访问getSelectedItem()
我添加了init（）; 构造函数的方法，它将导致此错误
setOnClickListener()同样的原因，在这种情况下，它是init()末尾对setOnClickListener()的调用。
在这两种情况下，您都假定在调用构造函数时，XML文件中定义的视图层次结构已经完全膨胀了……这是错误的。 调用构造函数时，下面的所有子视图尚未被放大和添加。
如果要以编写init()方法的方式获取对子视图的引用，则必须等到触发onFinishInflate()方法（ docs link ）。 重写此方法，然后在其中调用init() …不在构造函数中：
@Override
protected void onFinishInflate () {
init();
}
然后，您尝试调用访问器方法的尝试将按预期工作。
访问自定义选项卡类方法
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