Question

我必须动态地将一个String值设置为android中的textview，但不幸的是我得到了null值错误但是在日志中我可以打印String的值。所以我确信该字符串不是null但是非常大。这是我的logcat结果：

2-06 16:05:39.930  11631-11631/sarath.com.reachmeE/from_address﹕ Sub Jail Rd, Talap
Kannur, Kerala 670002
11.877453, 75.372992
12-06 16:05:39.940  11631-11631/sarath.com.reachmeE/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{sarath.com.reachme/sarath.com.reachme.app.Mapview}: java.lang.NullPointerException
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1970)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1995)
        at android.app.ActivityThread.access$600(ActivityThread.java:128)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1161)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:137)
        at android.app.ActivityThread.main(ActivityThread.java:4517)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:511)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:993)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:760)
        at dalvik.system.NativeStart.main(Native Method)
        Caused by: java.lang.NullPointerException
        at sarath.com.reachme.app.Mapview.onCreate(Mapview.java:95)
        at android.app.Activity.performCreate(Activity.java:4470)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1053)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1934)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1995)
        at android.app.ActivityThread.access$600(ActivityThread.java:128)

这是我的代码段：

Log.e("addrs short", String.valueOf(from_address));
address.setText(String.valueOf(from_address));

textview显示的字符串的大小/长度是否有限制？

Answer 1

您可能不会提及您的地址字段，这就是您收到此错误的原因。

address = (TextView) findElementById(R.id.your_address_id);

Answer 2

对字符串大小没有限制。几乎可以肯定错误是地址TextView为空，如果您执行findElementById(R.id.your_address_id);但视图(R.id.your_address_id)位于另一个活动中，则可能会发生此错误。

Textview.setText（addressString）返回null值错误

2 个答案: