我有两个片段。片段A和片段B。片段A有一个名为EmpID的EditText视图。片段B有一个名为"提交"的按钮。当我点击片段B中的Submit按钮时,我想检索片段A中EmpID中输入的值。我正在尝试使用OnClickListener中的以下代码来完成此操作:
EditText empID = (EditText) getView().findViewById(R.id.EmpID);
String empIDStr = empID.getText().toString(); //I get null here
但是,即使输入了数据,我也会得到一个空值。难道我不能从另一个片段中不获取EditText视图的值吗?我肯定我错过了什么。如有任何帮助,我们将不胜感激。谢谢
Here's the logcat output:
01-23 12:32:13.883: E/AndroidRuntime(1171): FATAL EXCEPTION: main
01-23 12:32:13.883: E/AndroidRuntime(1171): java.lang.NullPointerException
01-23 12:32:13.883: E/AndroidRuntime(1171): at ex.testApp.FragmentB$1.onClick(FragmentB.java:85)
01-23 12:32:13.883: E/AndroidRuntime(1171): at android.view.View.performClick(View.java:3110)
01-23 12:32:13.883: E/AndroidRuntime(1171): at android.view.View$PerformClick.run(View.java:11928)
01-23 12:32:13.883: E/AndroidRuntime(1171): at android.os.Handler.handleCallback(Handler.java:587)
01-23 12:32:13.883: E/AndroidRuntime(1171): at android.os.Handler.dispatchMessage(Handler.java:92)
01-23 12:32:13.883: E/AndroidRuntime(1171): at android.os.Looper.loop(Looper.java:132)
01-23 12:32:13.883: E/AndroidRuntime(1171): at android.app.ActivityThread.main(ActivityThread.java:4025)
01-23 12:32:13.883: E/AndroidRuntime(1171): at java.lang.reflect.Method.invokeNative(Native Method)
01-23 12:32:13.883: E/AndroidRuntime(1171): at java.lang.reflect.Method.invoke(Method.java:491)
01-23 12:32:13.883: E/AndroidRuntime(1171): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
01-23 12:32:13.883: E/AndroidRuntime(1171): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
01-23 12:32:13.883: E/AndroidRuntime(1171): at dalvik.system.NativeStart.main(Native Method)
这里是FragmentB.java:
public class FragmentB extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.FragmentB, container, false);
}
@Override
public void onStart() {
super.onStart();
final Button btnLeft = (Button) getActivity().findViewById(R.id.btnLeft);
final Button btnRight = (Button) getActivity().findViewById(R.id.btnRight);
buttonClick(btnLeft, btnRight);
}
private void buttonClick(final Button btnLeft, final Button btnRight) {
btnLeft.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
if (btnLeft.getText().equals("Submit")) {
EditText empID = (EditText) getView().findViewById(R.id.EmpID);
String empIDStr = empID.getText().toString(); //I get null here
.....
我只是将变量设置为static,它就工作了。
private static EditText empID;