我一直在通过我的三星S7手机(API 23和6.0.1)在Android Studio模拟器中测试我的应用程序,它工作正常。当我从笔记本电脑上拔下它并运行应用程序时,它会崩溃。Android - 空数组。在Android Studio模拟器中运行,但不在实际设备上时拔出
我的logcat说我试图调用一个空数组......但它不是空的?我不明白为什么当我通过Android Studio运行应用程序到我的手机时,一切正常,但是当我单独运行它时,它会崩溃。感谢任何帮助!
这里是我的logcat
FATAL EXCEPTION: main
Process: com.example.abc.def, PID: 28693
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.abc.def/com.example.abc.def.MainActivity}: java.lang.NullPointerException: Attempt to read from null array
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3253)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3349)
at android.app.ActivityThread.access$1100(ActivityThread.java:221)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1794)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7224)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
Caused by: java.lang.NullPointerException: Attempt to read from null array
at com.example.abc.def.MainActivity.onCreate(MainActivity.java:49)
at android.app.Activity.performCreate(Activity.java:6876)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1135)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3206)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3349)
at android.app.ActivityThread.access$1100(ActivityThread.java:221)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1794)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7224)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
这里是我的代码。该问题出现在底部,当我打电话btn1.setText(itemArray [0]),因为数组是“空”
public class MainActivity extends AppCompatActivity {
Button btn1, btn2;
String btn1Name, btn2Name;
String btnValue = "", itemValue = "", itemPosition = "";
String[] buttonArray = new String[]{"blank", "blank"};
String[] itemArray = new String[]{"blank", "blank"};
String[] positionArray = new String[]{"blank", "blank"};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn1 = (Button) findViewById(R.id.button1);
btn2 = (Button) findViewById(R.id.button2);
Bundle extras = getIntent().getExtras();
if (extras != null) {
btnValue = extras.getString("btnValue");
itemValue = extras.getString("itemValue");
itemPosition = extras.getString("itemPosition");
buttonArray = extras.getStringArray("buttonArray");
itemArray = extras.getStringArray("array");
positionArray = extras.getStringArray("positionArray");
if (btnValue != null && btnValue.equals("btn1")){
buttonArray[0] = btnValue;
itemArray[0] = itemValue;
positionArray[0] = itemPosition;
} else if (btnValue != null && btnValue.equals("btn2")) {
buttonArray[1] = btnValue;
itemArray[1] = itemValue;
positionArray[1] = itemPosition;
}
}
btn1.setText(itemArray[0]);
btn2.setText(itemArray[1]);
}
}
什么是由“extras.getString(”itemValue“)”&“itemArray = extras.getStringArray(”array“);”? –
@AdeelShahzad来自另一项活动。我不认为它与我的代码有任何关系,但因为在我启动应用程序时“extras”应该为空。 itemArray [0]和[1]已在活动启动时分配给“空白”。 – Pam
你可以请张贴其他班级代码,你通过这些额外的? –