如何在活动启动时获取静态字符串初始化文本视图

Question

每当我启动此活动时，我都试图使用静态字符串初始化我的文本视图，但模拟器总是强制关闭该活动。。有人能帮我吗？

这是代码：

// ServiceAct.java
public class ServiceAct extends Activity
{
    static String[] phoneno = {"No Number", "No Number", "No Number"};
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        // to set the contacts value in status module
        TextView v1 = (TextView) findViewById(R.id.stat_con1);
        v1.setText(phoneno[0]);
        //remaining code of the activity
        ....
    }
}

这是logcat

FATAL EXCEPTION: main java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.service/com.example.service.ServiceAct}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
at android.app.ActivityThread.access$1500(ActivityThread.java:117)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:123)
at android.app.ActivityThread.main(ActivityThread.java:3683)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:507)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.example.service.ServiceAct.onCreate(ServiceAct.java:31)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)

这是布局代码：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:weightSum="1"  android:layout_height="fill_parent"  android:orientation="horizontal"  android:layout_width="fill_parent"  android:background="@color/background" >
    <RelativeLayout android:layout_height="match_parent"  android:layout_width="match_parent"  android:layout_gravity="center"  android:id="@+id/relativeLayout2">
        <TextView android:text="No Number"  android:id="@+id/stat_con1"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:textAppearance="?android:attr/textAppearanceLarge" />
    </RelativeLayout>
</LinearLayout>

Answer 1

你试过清理你的项目吗？这看起来就像是这样的错误（因为其他一切看起来都很好）。如果您在Eclipse中进行开发，请转到project->clean。选择所有项目。你可能还需要重建后记。此外，如果这没有帮助，请尝试重新启动IDE。

Answer 2

从您发布的代码中，我可以看到两个可能的错误：

• TextView v1为null，这意味着布局文件没有任何id为R.id.stat_con1的TextView
• id为R.id.stat_con1的视图不是TextView，并且在转换为TextView时失败

更新：

Caused by: java.lang.NullPointerException
at com.example.service.ServiceAct.onCreate(ServiceAct.java:31)

检查第31行…该行中的某些内容为空。