Question

我刚接触Android工作室，我遇到了这个问题。我无法获取我的EditText字符串并将其作为短信发送。当我使用EditText时应用程序崩溃，但当我使用固定的单词时，它运行得非常好。

这是我的MainActivity：

public class MainActivity extends AppCompatActivity implements communicator{
..
....
..


EditText t1,t2,t3,t4;
        String phoneNo="09857512187",sms;
    ..
...
...

    @Override
    protected void onCreate(Bundle savedInstanceState){


     ...
...
...
...

        ttl=(TextView) findViewById(R.id.total);
        done=(Button) findViewById(R.id.done);
        t1=(EditText)findViewById(R.id.first_name);
        t2=(EditText)findViewById(R.id.last_name);
        t3=(EditText)findViewById(R.id.numberInput);
        t4=(EditText)findViewById(R.id.address);
sms=t1.getText().toString()+t2.getText().toString()+t3.getText().toString()+t4.getText().toString();
    }


    public void done(View v){
            SmsManager smsManager = SmsManager.getDefault();
            smsManager.sendTextMessage(phoneNo, null, sms, null, null);
            Toast.makeText(getApplicationContext(), "SMS Sent!",
                    Toast.LENGTH_LONG).show();
    }

并且继承了logcat：

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.jackreynaldo.tab/com.example.jackreynaldo.tab.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.text.Editable android.widget.EditText.getText()' on a null object reference
                                                                                  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2351)
                                                                                  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2413)
                                                                                  at android.app.ActivityThread.access$800(ActivityThread.java:154)
                                                                                  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1316)
                                                                                  at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                                  at android.os.Looper.loop(Looper.java:135)
                                                                                  at android.app.ActivityThread.main(ActivityThread.java:5357)
                                                                                  at java.lang.reflect.Method.invoke(Native Method)
                                                                                  at java.lang.reflect.Method.invoke(Method.java:372)
                                                                                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:952)
                                                                                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:747)
                                                                               Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.text.Editable android.widget.EditText.getText()' on a null object reference
                                                                                  at com.example.jackreynaldo.tab.MainActivity.onCreate(MainActivity.java:109)
                                                                                  at android.app.Activity.performCreate(Activity.java:6012)
                                                                                  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
                                                                                  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2295)
                                                                                  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2413) 
                                                                                  at android.app.ActivityThread.access$800(ActivityThread.java:154) 
                                                                                  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1316) 
                                                                                  at android.os.Handler.dispatchMessage(Handler.java:102) 
                                                                                  at android.os.Looper.loop(Looper.java:135) 
                                                                                  at android.app.ActivityThread.main(ActivityThread.java:5357) 
                                                                                  at java.lang.reflect.Method.invoke(Native Method) 
                                                                                  at java.lang.reflect.Method.invoke(Method.java:372) 
                                                                                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:952) 
                                                                                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:747)

注意：完成是我的onClick for my button

Answer 1

根据LogCat，您的某个edittext未正确初始化。确保引用正确的资源ID。

如何在android studio中使用EditText作为消息

1 个答案: