我打电话的时候：
channel_name = textinput.getText().toString();
我收到NullPointerException。 我认为我的问题在于代码行：
final EditText textinput = (EditText)findViewById(R.id.popup_plaintext);
但我找不到错误。 我也用过搜索，但我仍然没有得到它。 我希望有人可以帮助我。
在这里，您可以查看我的完整代码：
package de.project.ibob;
import android.app.Activity;
import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.util.Log;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnLongClickListener;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.PopupWindow;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.RadioGroup.OnCheckedChangeListener;
import android.widget.Switch;
public class ModuleActivity extends Activity{
//Data
int a = 16;
int b = 6;
byte[][] buffer = new byte[a][b];
public int LongClickID;
public String channel_name;
//Debugging
private static final String TAG = "ModuleActivity";
private static final boolean D = true;
//Layout
private PopupWindow pwindo;
private RadioGroup mradiogroup;
private RadioButton mradiobutton[] = new RadioButton[7];
private Switch mswitch[] = new Switch[33];
private Button buttonClosePopup;
public Switch textoutput;
private void SavePreferences() {
SharedPreferences settings = getSharedPreferences("Channels", 0);
SharedPreferences.Editor editor = settings.edit();
//Buttons
for(int i = 1; i < 7; i++) {
editor.putBoolean("radio" + i, mradiobutton[i].isChecked());
}//for
for(int i = 1; i < 33; i++) {
editor.putBoolean("switch" + i, mswitch[i].isChecked());
}//for
editor.commit();
}//SafePreferences
private void LoadPreferences() {
SharedPreferences settings = getSharedPreferences("Channels", 0);
//
//Buttons
for(int i = 1; i < 7; i++) {
mradiobutton[i].setChecked(settings.getBoolean("radio" + i, false));
}//for
for(int i = 1; i < 33; i++) {
mswitch[i].setChecked(settings.getBoolean("switch" + i, false));
}//for
}//LoadPreferences
@Override
public void onCreate(Bundle savedInstanceState) {
if(D) Log.e(TAG, "+++ ON CREATE +++");
super.onCreate(savedInstanceState);
//Layout
setContentView(R.layout.modules);
//RadioGroup
mradiogroup = (RadioGroup)findViewById(R.id.radio_group_modules);
//RadioButtons (i = 1 because of radiobutton_modules_module ID starts at 1! ==> i <7 NOT 6!)
for(int i = 1; i < 7; i++) {
String RadioID = "radiobutton_modules_module" + i;
int resID = getResources().getIdentifier(RadioID, "id", "de.project.ibob");
mradiobutton[i] = ((RadioButton)findViewById(resID));
if(D) Log.e(TAG, "+++ SetRadioButton +++" + i);
}//for
//Switches (i = 1 because of Switch ID starts at 1! ==> i <33 NOT 32!)
for(int i = 1; i < 33; i++) {
String SwitchID = "Switch" + i;
int resID = getResources().getIdentifier(SwitchID, "id", "de.project.ibob");
mswitch[i] = ((Switch)findViewById(resID));
mswitch[i].setOnLongClickListener(new OnLongClickListener(){
@Override
public boolean onLongClick(View v) {
if(D) Log.e(TAG, "+++ LongClick +++" + v.getId());
LongClickID = v.getId();
initiatePopupWindow();
return true;
}
});
if(D) Log.e(TAG, "+++ Switch +++" + i);
}//for
//Buttons Listener
mradiogroup.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(RadioGroup group, int mradiogroup) {
for(int i = 1; i < 7; i++) {
if(mradiobutton[i].isChecked() == true) {
if(D) Log.e(TAG, "+++ RadioButton selected +++");
//Identifier (MODUL - Read/Write - Channel) all 16 Messages get the same ModulID
for(a = 0; a < 15; a++) {
if(i == 1)buffer[a][0] = 0x01;
if(i == 2)buffer[a][1] = 0x02;
if(i == 3)buffer[a][2] = 0x03;
if(i == 4)buffer[a][3] = 0x04;
if(i == 5)buffer[a][4] = 0x05;
if(i == 6)buffer[a][5] = 0x06;
}//for
if(D) Log.e(TAG, "ID Byte:" + i + " selected");
}//if
}//for
}//onCheckedChanged
});//setOnCheckedChangedListener
//Functions
LoadPreferences();
}//onCreate
@Override
public void onBackPressed() {
SavePreferences();
super.onBackPressed();
if(D) Log.e(TAG, "+++ onBackPressed +++");
}//onBackPressed
public void initiatePopupWindow() {
try{
LayoutInflater inflater = (LayoutInflater)
ModuleActivity.this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View layout = inflater.inflate(R.layout.popup,
(ViewGroup)findViewById(R.id.popup_element));
pwindo = new PopupWindow(layout,600,250,true);
pwindo.showAtLocation(layout, Gravity.CENTER,0,0);
buttonClosePopup = (Button)layout.findViewById(R.id.button_modules_popup_setText);
buttonClosePopup.setOnClickListener(cancel_button_click_listener);
}//try
catch(Exception e) {
e.printStackTrace();
}
}
public OnClickListener cancel_button_click_listener = new OnClickListener(){
@Override
public void onClick(View cancel_button_click_listener){
final EditText textinput = (EditText)findViewById(R.id.popup_plaintext);
channel_name = textinput.getText().toString();
textoutput = (Switch)findViewById(LongClickID);
textoutput.setText(channel_name);
pwindo.dismiss();
}
};
}
堆栈跟踪：
01-26 00:13:58.071: E/AndroidRuntime(15877): FATAL EXCEPTION: main
01-26 00:13:58.071: E/AndroidRuntime(15877): java.lang.NullPointerException
01-26 00:13:58.071: E/AndroidRuntime(15877): at de.project.ibob.ModuleActivity$1.onClick(ModuleActivity.java:205)
01-26 00:13:58.071: E/AndroidRuntime(15877): at android.view.View.performClick(View.java:4232)
01-26 00:13:58.071: E/AndroidRuntime(15877): at android.view.View$PerformClick.run(View.java:17318)
01-26 00:13:58.071: E/AndroidRuntime(15877): at android.os.Handler.handleCallback(Handler.java:615)
01-26 00:13:58.071: E/AndroidRuntime(15877): at android.os.Handler.dispatchMessage(Handler.java:92)
01-26 00:13:58.071: E/AndroidRuntime(15877): at android.os.Looper.loop(Looper.java:137)
01-26 00:13:58.071: E/AndroidRuntime(15877): at android.app.ActivityThread.main(ActivityThread.java:4921)
01-26 00:13:58.071: E/AndroidRuntime(15877): at java.lang.reflect.Method.invokeNative(Native Method)
01-26 00:13:58.071: E/AndroidRuntime(15877): at java.lang.reflect.Method.invoke(Method.java:511)
01-26 00:13:58.071: E/AndroidRuntime(15877): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038)
01-26 00:13:58.071: E/AndroidRuntime(15877): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805)
01-26 00:13:58.071: E/AndroidRuntime(15877): at dalvik.system.NativeStart.main(Native Method)
在这里你可以看到我的布局xml代码：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/popup_element"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#444444" >
<TextView
android:id="@+id/popup_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="32dp"
android:text="@string/set_name"
android:textAppearance="?android:attr/textAppearanceLarge"
android:textColor="@android:color/white" />
<Button
android:id="@+id/button_modules_popup_setText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/popup_plaintext"
android:layout_centerHorizontal="true"
android:layout_marginTop="21dp"
android:text="@string/set_channelname"
android:textColor="@android:color/white" />
<EditText
android:id="@+id/popup_plaintext"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/popup_text"
android:layout_centerHorizontal="true"
android:layout_marginTop="21dp"
android:ems="10"
android:inputType="text"
android:textColor="@android:color/white" />
</RelativeLayout>
谢谢
答案 0 :(得分：0)
你在findView上遗漏了一个标识符，我通过将弹出视图添加到findViewById（）修复了类似的NPE。如果我的观点正确，这应该可以解决问题
final EditText textinput = (EditText)layout.findViewById(R.id.popup_plaintext);