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我試圖改變3個textviews在一個叫做用戶配置（）調用從類UpdateProfile（方法更新（）），該類用戶配置類一個TextView覆蓋文本做這樣的事情：Android應用程序崩潰時，試圖從其他類
package com.safm;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
public class UserProfile extends Activity {
TextView username, usersurname, useremail;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_profile);
username = (TextView) findViewById(R.id.username);
usersurname = (TextView) findViewById(R.id.usersurname);
useremail = (TextView) findViewById(R.id.useremail);
}
public void updateButton(View view){
Intent i = new Intent(this, UpdateProfile.class);
startActivity(i);
}
public void update(String nname, String nusername, String nemail){
System.out.println("2");
System.out.println(nname);
username.setText(nname);
usersurname.setText(nusername);
useremail.setText(nemail);
System.out.println("3");
}
}
的updateButton方法調用UpdateProfile類：
package com.safm;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;
public class UpdateProfile extends Activity {
EditText newusernametxt, newsurnametxt, newemailtxt;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_actualizarperfil);
newusernametxt = (EditText) findViewById(R.id.newusernametxt);
newsurnametxt = (EditText) findViewById(R.id.newsurnametxt);
newemailtxt = (EditText) findViewById(R.id.newemailtxt);
}
public void updateInfo(View view){
String nname = newusernametxt .getText().toString();
String nsurname = newsurnametxt .getText().toString();
String nemail = newemailtxt .getText().toString();
if(nname.compareTo("") != 0 && nsurname.compareTo("") != 0 && nemail.compareTo("") != 0){
UserProfile profile = new UserProfile();
System.out.println("1");
profile.update(nname, nsurname, nemail);
System.out.println("4");
Toast.makeText(this, "Success, the profile has been updated", Toast.LENGTH_SHORT).show();
}else{
Toast.makeText(this, "You can't empty fields", Toast.LENGTH_SHORT).show();
}
}
這是我logcat的文件，你可以看到，第2個標誌打印正確，錯誤的是，當我嘗試設置TextView上的另一個文本，但字符串的值（nname，nsurname和nemail）不是空的原因也被打印在控制檯HELP！
05-14 21:43:31.140: I/System.out(878): 1
05-14 21:43:31.140: I/System.out(878): 2
05-14 21:43:31.150: I/System.out(878): TextEditValue
05-14 21:43:31.150: D/AndroidRuntime(878): Shutting down VM
05-14 21:43:31.150: W/dalvikvm(878): threadid=1: thread exiting with uncaught exception (group=0x40a71930)
05-14 21:43:31.310: E/AndroidRuntime(878): FATAL EXCEPTION: main
05-14 21:43:31.310: E/AndroidRuntime(878): java.lang.IllegalStateException: Could not execute method of the activity
05-14 21:43:31.310: E/AndroidRuntime(878): at android.view.View$1.onClick(View.java:3599)
05-14 21:43:31.310: E/AndroidRuntime(878): at android.view.View.performClick(View.java:4204)
05-14 21:43:31.310: E/AndroidRuntime(878): at android.view.View$PerformClick.run(View.java:17355)
05-14 21:43:31.310: E/AndroidRuntime(878): at android.os.Handler.handleCallback(Handler.java:725)
05-14 21:43:31.310: E/AndroidRuntime(878): at android.os.Handler.dispatchMessage(Handler.java:92)
05-14 21:43:31.310: E/AndroidRuntime(878): at android.os.Looper.loop(Looper.java:137)
05-14 21:43:31.310: E/AndroidRuntime(878): at android.app.ActivityThread.main(ActivityThread.java:5041)
05-14 21:43:31.310: E/AndroidRuntime(878): at java.lang.reflect.Method.invokeNative(Native Method)
05-14 21:43:31.310: E/AndroidRuntime(878): at java.lang.reflect.Method.invoke(Method.java:511)
05-14 21:43:31.310: E/AndroidRuntime(878): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
05-14 21:43:31.310: E/AndroidRuntime(878): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
05-14 21:43:31.310: E/AndroidRuntime(878): at dalvik.system.NativeStart.main(Native Method)
05-14 21:43:31.310: E/AndroidRuntime(878): Caused by: java.lang.reflect.InvocationTargetException
05-14 21:43:31.310: E/AndroidRuntime(878): at java.lang.reflect.Method.invokeNative(Native Method)
05-14 21:43:31.310: E/AndroidRuntime(878): at java.lang.reflect.Method.invoke(Method.java:511)
05-14 21:43:31.310: E/AndroidRuntime(878): at android.view.View$1.onClick(View.java:3594)
05-14 21:43:31.310: E/AndroidRuntime(878): ... 11 more
05-14 21:43:31.310: E/AndroidRuntime(878): Caused by: java.lang.NullPointerException
05-14 21:43:31.310: E/AndroidRuntime(878): at com.safm.UserProfile.update(UserProfile.java:31)
05-14 21:43:31.310: E/AndroidRuntime(878): at com.safm.UserProfile.updateInfo(UpdateProfile.java:33)
05-14 21:43:31.310: E/AndroidRuntime(878): ... 14 more
注：我乾淨的項目，並定義的ProfileUser類的TextView和onCreate方法之外的文本編輯在UpdateProfile但不起作用。
謝謝。