Question

我仍然对如何在Fragments上实现按钮处理程序感到困惑。

这是我的片段：

package com.example.myshops_diary;
import java.text.SimpleDateFormat;
import java.util.Calendar;

import android.app.Activity;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.app.Fragment;
import android.os.Bundle;
import android.view.Gravity;
import android.view.LayoutInflater; 
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class Item1_fragment extends Fragment implements OnClickListener { 

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

    View view = inflater.inflate(R.layout.item1_fragment, container, false);

    Button nextpageButton = (Button) view.findViewById(R.id.nextpageButton);
nextpageButton.setOnClickListener(this);
return view;
}

@Override
public void onClick(View v) {
    switch (v.getId()) {
    case R.id.nextpageButton:
    Toast.makeText(getActivity().getApplicationContext(), "Button clicked!", Toast.LENGTH_LONG).show();


        break;
    }

}

private void setContentView(int item2_Fragment) {
    // TODO Auto-generated method stub



    //---Inflate the layout for this fragment---
//return inflater.inflate( R.layout.item1_fragment, container, false);



}





}

当我点击应用程序停止运行的“下一步”按钮时，这些代码仍然无法正常工作。

**这些是我的LogCat：

04-14 13:00:15.899: D/dalvikvm(537): Not late-enabling CheckJNI (already on)
04-14 13:00:17.359: D/gralloc_goldfish(537): Emulator without GPU emulation detected.
04-14 13:00:28.289: D/AndroidRuntime(537): Shutting down VM
04-14 13:00:28.299: W/dalvikvm(537): threadid=1: thread exiting with uncaught exception (group=0x409961f8)
04-14 13:00:28.309: E/AndroidRuntime(537): FATAL EXCEPTION: main
04-14 13:00:28.309: E/AndroidRuntime(537): java.lang.IllegalStateException: Could not find a method nextClick(View) in the activity class com.example.myshops.MainActivity for onClick handler on view class android.widget.Button with id 'nextpageButton'
04-14 13:00:28.309: E/AndroidRuntime(537):  at android.view.View$1.onClick(View.java:3026)
04-14 13:00:28.309: E/AndroidRuntime(537):  at android.view.View.performClick(View.java:3480)
04-14 13:00:28.309: E/AndroidRuntime(537):  at android.view.View$PerformClick.run(View.java:13983)
04-14 13:00:28.309: E/AndroidRuntime(537):  at android.os.Handler.handleCallback(Handler.java:605)
04-14 13:00:28.309: E/AndroidRuntime(537):  at android.os.Handler.dispatchMessage(Handler.java:92)
04-14 13:00:28.309: E/AndroidRuntime(537):  at android.os.Looper.loop(Looper.java:137)
04-14 13:00:28.309: E/AndroidRuntime(537):  at android.app.ActivityThread.main(ActivityThread.java:4340)
04-14 13:00:28.309: E/AndroidRuntime(537):  at java.lang.reflect.Method.invokeNative(Native Method)
04-14 13:00:28.309: E/AndroidRuntime(537):  at java.lang.reflect.Method.invoke(Method.java:511)
04-14 13:00:28.309: E/AndroidRuntime(537):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
04-14 13:00:28.309: E/AndroidRuntime(537):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
04-14 13:00:28.309: E/AndroidRuntime(537):  at dalvik.system.NativeStart.main(Native Method)
04-14 13:00:28.309: E/AndroidRuntime(537): Caused by: java.lang.NoSuchMethodException: nextClick [class android.view.View]
04-14 13:00:28.309: E/AndroidRuntime(537):  at java.lang.Class.getConstructorOrMethod(Class.java:460)
04-14 13:00:28.309: E/AndroidRuntime(537):  at java.lang.Class.getMethod(Class.java:915)
04-14 13:00:28.309: E/AndroidRuntime(537):  at android.view.View$1.onClick(View.java:3019)
04-14 13:00:28.309: E/AndroidRuntime(537):  ... 11 more

Answer 1

您的onClick方法看起来不错。我不知道您尝试做什么，但是无法两次设置内容视图。您已经在onCreateView方法中夸大了一个视图：

inflater.inflate(R.layout.item1_fragment, container, false);

然后你不能在下面调用这段代码来添加布局。这是导致崩溃的原因：

setContentView(R.layout.item2_fragment);

还要确保在布局中点击的按钮具有以下ID：

<Button
    android:id="@+id/nextpageButton"
    ... />

由于android:onClick="nextClick"属性，您遇到此错误：NoSuchMethodException: nextClick。这意味着系统无法找到名为nextClick 的方法。您尝试通过按钮调用onClickListener方法和 onClick方法。

然后，删除布局中的属性并将此部分保留在Activity：

中

@Override
public void onClick(View v) {
    switch (v.getId()) {
        // This will display a Toast (msg) when the button is clicked
        case R.id.nextpageButton:
            Toast.makeText(getActivity().getApplicationContext(), "Button clicked!", Toast.LENGTH_LONG).show();
        break;
    }
}

See the documentation看两种不同的方法。

更新

您可以按如下方式设置点击侦听器：

// Here the inflated view (the layout) and the button are the same variable..
view = (Button) view.findViewById(R.id.nextpageButton);
view.setOnClickListener(this);

但您应该使用不同的变量按钮，如下所示：

// Here we give another name variable as "button_name" and also we set the widget "Button"
Button button_name = (Button) view.findViewById(R.id.nextpageButton);
button_name.setOnClickListener(getActivity());

<强>解决方案

这里有另一种方法，直接调用没有工具的onClickListener。删除它：

implements OnClickListener // on your Fragment Class declaration

然后：

nextpageButton.setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View v) {
        Toast.makeText(getActivity().getApplicationContext(), "Button clicked!", Toast.LENGTH_LONG).show();
    }
});

解决方案2

删除Activity中的所有onClick方法等。在布局中添加以下属性：

android:onClick="nextpageButton" // on your button

然后在您的活动中：

// call the "nextpageButton" inside your activity as
public void nextpageButton(View view) {
    Toast.makeText(getActivity().getApplicationContext(), "Button clicked!", Toast.LENGTH_LONG).show();
}

Answer 2

试试这个。

public static class PlaceholderFragment extends Fragment implements
        OnClickListener {

    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_job_seeker_home,
                container, false);
        Button bu = (Button) rootView.findViewById(R.id.next);
        bu.setOnClickListener(this);
        return rootView;
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.next:
        Toast.makeText(getActivity().getApplicationContext(), "Button clicked!", Toast.LENGTH_LONG).show();
            break;
        }
    }
}

Answer 3

在MainActivity中，首先给片段充气，

<Button
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="click"
    android:id="@+id/btnOne"
/>

片段布局中的按钮应如下所示

Button btnOne=(Button)view.findViewById(R.id.btnOne);
    btnOne.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Intent i=new Intent(getActivity(),secondActivity.class);
            startActivity(i);
        }
    });

据我所知，您想使用按钮点击事件打开另一个活动。如果我错了，请纠正我。但是，如果要使用片段中的按钮打开新活动，请尝试以下代码。

awk

＆＃39; secondActivity＆＃39;是您要打开的活动的名称。

如何在Fragments上实现Buttons clickhandler

3 个答案: