UPDATE無法解析方法maketext
當我使用此代碼Toast.makeText(Lesson111.this,rb.getText(),Toast.LENGTH_SHORT).show();我收到錯誤消息說不能解決方法maketext。然後我看到這個(The method makeText in the type Toast is not applicable for the arguments)我應用了代碼Toast.makeText(Lesson111.this.getActivity(),rb.getText(),Toast.LENGTH_SHORT).show();而不是Toast.makeText(Lesson111.this,rb.getText(),Toast.LENGTH_SHORT).show(); 。這個錯誤不知何故就消失了。但是,當我嘗試運行該應用程序並單擊Lesson111時。它迫使應用程序關閉。我錯過了什麼嗎?
package com.android.pet.view;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.View;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.Toast;
import android.view.LayoutInflater;
import android.view.ViewGroup;
import com.doepiccoding.navigationdrawer.R;
public class Lesson111 extends Fragment {
private RadioGroup radioGroup;
public View onCreateView(LayoutInflater Inflater, ViewGroup container,Bundle savedInstanceState) {
View rootView = Inflater.inflate(R.layout.twopointthree, null);
/* Initialize Radio Group and attach click handler */
radioGroup = (RadioGroup) rootView.findViewById(R.id.radioGroup);
radioGroup.clearCheck();
/* Attach CheckedChangeListener to radio group */
radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
RadioButton rb = (RadioButton) group.findViewById(checkedId);
if(null!=rb && checkedId > -1){
Toast.makeText(Lesson111.this.getActivity(), rb.getText(), Toast.LENGTH_SHORT).show();
}
}
});
return rootView;
}
public void onClear(View v) {
/* Clears all selected radio buttons to default */
radioGroup.clearCheck();
}
public void onSubmit(View v) {
RadioButton rb = (RadioButton) radioGroup.findViewById(radioGroup.getCheckedRadioButtonId());
Toast.makeText(Lesson111.this.getActivity(), rb.getText(), Toast.LENGTH_SHORT).show();
}
}
這裏顯示的內容在logcat中,進出口使用藍疊作爲模擬器
6月3日至27日:04:19.703 7458-7458 /? E/AndroidRuntime:致命例外:main 進程:com.doepiccoding.navigationdrawer,PID:7458 java.lang.NullPointerException at com.android.pet.view.Lesson111.onCreateView(Lesson111.java:22) at android。 support.v4.app.Fragment.performCreateView(Fragment.java:1478) at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:927) at android.support.v4.app.FragmentManagerImpl.moveToState( FragmentManager.java:1104) at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682) at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1460) android.support.v4.app.FragmentManagerImpl $ 1.run(FragmentManager.java:440) 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:5021) at java.lang.reflect.Method.invokeNative(Native Method) 在java.lang.reflect.Method.invoke(Method.java:515) 在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run(ZygoteInit.java:827) 在com.android.internal.os.ZygoteInit .main(ZygoteInit.java:643) at dalvik.system.NativeStart.main(Native Method)
你能張貼logcat的PLZ一RadioGroup中?所以我們可以看到當您嘗試顯示Toast時拋出了什麼異常。我想Lesson111.this.getActivity()可能會返回null,但很難確認沒有日誌 –
@KevinLEGOFF我已經更新了帖子,此外,Im使用bluestacks作爲模擬器 – Dreamer