我正在尝试在我的onClick(View v)XML中调用该方法,但不能与Fragment一起使用。这是错误。
01-17 12:38:36.840: E/AndroidRuntime(4171): java.lang.IllegalStateException:
Could not find a method insertIntoDb(View) in the activity class main.MainActivity
for onClick handler on view class android.widget.Button with id 'btn_conferma'
MainActivity.java
public void insertIntoDb(View v) {
...
}
xml代码
<Button
android:id="@id/btn_conferma"
style="?android:attr/borderlessButtonStyle"
android:layout_width="0.0dip"
android:layout_height="45dp"
android:layout_marginLeft="2dp"
android:layout_weight="1.0"
android:background="@drawable/bottoni"
android:gravity="center_horizontal|center_vertical"
android:onClick="insertIntoDb"
android:text="SALVA"
android:textColor="#ffffff"
android:textSize="16sp" />
答案 0 :(得分:163)
您的活动必须
public void insertIntoDb(View v) {
...
}
不是片段。
如果您不想在活动中进行上述操作。初始化片段中的按钮并将侦听器设置为相同。
<Button
android:id="@+id/btn_conferma" // + missing
然后
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_rssitem_detail,
container, false);
Button button = (Button) view.findViewById(R.id.btn_conferma);
button.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v)
{
// do something
}
});
return view;
}
答案 1 :(得分:13)
另一种选择可能是让您的片段实现View.OnClickListener并覆盖片段中的onClick(View v)。如果您需要让片段与活动通信,只需添加具有所需方法的接口,并让活动实现接口并覆盖其方法。
public class FragName extends Fragment implements View.OnClickListener {
public FragmentCommunicator fComm;
public ImageButton res1, res2;
int c;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_test, container, false);
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
fComm = (FragmentCommunicator) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement FragmentCommunicator");
}
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
res1 = (ImageButton) getActivity().findViewById(R.id.responseButton1);
res1.setOnClickListener(this);
res2 = (ImageButton) getActivity().findViewById(R.id.responseButton2);
res2.setOnClickListener(this);
}
public void onClick(final View v) { //check for what button is pressed
switch (v.getId()) {
case R.id.responseButton1:
c *= fComm.fragmentContactActivity(2);
break;
case R.id.responseButton2:
c *= fComm.fragmentContactActivity(4);
break;
default:
c *= fComm.fragmentContactActivity(100);
break;
}
public interface FragmentCommunicator{
public int fragmentContactActivity(int b);
}
public class MainActivity extends FragmentActivity implements FragName.FragmentCommunicator{
int a = 10;
//variable a is update by fragment. ex. use to change textview or whatever else you'd like.
public int fragmentContactActivity(int b) {
//update info on activity here
a += b;
return a;
}
}
http://developer.android.com/training/basics/firstapp/starting-activity.html http://developer.android.com/training/basics/fragments/communicating.html
答案 2 :(得分:6)
这不是问题,这是Android的设计。见here:
您应该将每个片段设计为模块化和可重用的活动 零件。也就是说,因为每个片段都定义了自己的布局和 它自己的行为有自己的生命周期回调,你可以包含一个 片段在多个活动中,所以你应该设计为重用和 避免直接操纵另一个片段中的一个片段。
可能的解决方法是在MainActivity中执行类似的操作:
Fragment someFragment;
...onCreate etc instantiating your fragments
public void myClickMethod(View v){
someFragment.myClickMethod(v);
}
然后在你的Fragment类中:
public void myClickMethod(View v){
switch(v.getid()){
// Your code here
}
}
答案 3 :(得分:3)
其他人已经说过onClick中的方法是在活动中搜索的,而不是片段。然而,如果你真的想要它, 是可能的。
基本上,每个视图都有一个标记(可能为null)。我们将根视图的标记设置为膨胀该视图的片段。然后,很容易搜索视图父项并检索包含单击按钮的片段。现在,我们找出方法名称并使用反射从检索到的片段中调用相同的方法。简单!
扩展Fragment
的类
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_id, container, false);
OnClickFragments.registerTagFragment(rootView, this); // <========== !!!!!
return rootView;
}
public void onButtonSomething(View v) {
Log.d("~~~","~~~ MyFragment.onButtonSomething");
// whatever
}
所有活动都来自相同的ButtonHandlingActivity:
public class PageListActivity extends ButtonHandlingActivity
ButtonHandlingActivity.java:
public class ButtonHandlingActivity extends Activity {
public void onButtonSomething(View v) {
OnClickFragments.invokeFragmentButtonHandlerNoExc(v);
//or, if you want to handle exceptions:
// try {
// OnClickFragments.invokeFragmentButtonHandler(v);
// } catch ...
}
}
必须为所有xml onClick处理程序定义方法。
COM /示例/ customandroid / OnClickFragments.java:
package com.example.customandroid;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import android.app.Fragment;
import android.view.View;
public abstract class OnClickFragments {
public static class FragmentHolder {
Fragment fragment;
public FragmentHolder(Fragment fragment) {
this.fragment = fragment;
}
}
public static Fragment getTagFragment(View view) {
for (View v = view; v != null; v = (v.getParent() instanceof View) ? (View)v.getParent() : null) {
Object tag = v.getTag();
if (tag != null && tag instanceof FragmentHolder) {
return ((FragmentHolder)tag).fragment;
}
}
return null;
}
public static String getCallingMethodName(int callsAbove) {
Exception e = new Exception();
e.fillInStackTrace();
String methodName = e.getStackTrace()[callsAbove+1].getMethodName();
return methodName;
}
public static void invokeFragmentButtonHandler(View v, int callsAbove) throws IllegalAccessException, IllegalArgumentException, InvocationTargetException, NoSuchMethodException {
String methodName = getCallingMethodName(callsAbove+1);
Fragment f = OnClickFragments.getTagFragment(v);
Method m = f.getClass().getMethod(methodName, new Class[] { View.class });
m.invoke(f, v);
}
public static void invokeFragmentButtonHandler(View v) throws IllegalAccessException, IllegalArgumentException, InvocationTargetException, NoSuchMethodException {
invokeFragmentButtonHandler(v,1);
}
public static void invokeFragmentButtonHandlerNoExc(View v) {
try {
invokeFragmentButtonHandler(v,1);
} catch (NoSuchMethodException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
}
public static void registerTagFragment(View rootView, Fragment fragment) {
rootView.setTag(new FragmentHolder(fragment));
}
}
接下来的冒险将是节目混淆......
PS
当然,您可以设计应用程序,使数据存在于模型中,而不是活动或片段(来自 Controllers ) > MVC ,模型 - 视图 - 控制器观点)。 View 是您通过xml定义的,加上自定义视图类(如果您定义它们,大多数人只是重用已经存在的内容)。经验法则:如果某些数据肯定必须在屏幕转向中存活,它们属于模型。
答案 4 :(得分:2)
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.writeqrcode_main, container, false);
// Inflate the layout for this fragment
txt_name = (TextView) view.findViewById(R.id.name);
txt_usranme = (TextView) view.findViewById(R.id.surname);
txt_number = (TextView) view.findViewById(R.id.number);
txt_province = (TextView) view.findViewById(R.id.province);
txt_write = (EditText) view.findViewById(R.id.editText_write);
txt_show1 = (Button) view.findViewById(R.id.buttonShow1);
txt_show1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Log.e("Onclick","Onclick");
txt_show1.setVisibility(View.INVISIBLE);
txt_name.setVisibility(View.VISIBLE);
txt_usranme.setVisibility(View.VISIBLE);
txt_number.setVisibility(View.VISIBLE);
txt_province.setVisibility(View.VISIBLE);
}
});
return view;
}
你没关系!!!!
答案 5 :(得分:1)
对于Kotlin用户:
DELETE FROM DAILY_DIFF WHERE ID in (SELECT ID FROM TNT.DAILY_DIFF
WHERE TO_CHAR(DIFF_DATE, 'YYYY-MM-DD') = '${today}')
答案 6 :(得分:0)
如果你想使用数据绑定,你可以按照这个解决方案 以下解决方案可能是更好的解决方案。布局在 fragment_my.xml
<data>
<variable
name="listener"
type="my_package.MyListener" />
</data>
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<Button
android:id="@+id/moreTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@{() -> listener.onClick()}"
android:text="@string/login"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
片段如下
class MyFragment : Fragment(), MyListener {
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
return FragmentMyBinding.inflate(
inflater,
container,
false
).apply {
lifecycleOwner = viewLifecycleOwner
listener = this@MyFragment
}.root
}
override fun onClick() {
TODO("Not yet implemented")
}
}
interface MyListener{
fun onClick()
}