获取EditText字段的值

Question

我想让用户输入玩家数量，然后当按下按钮时，它会提交金额并移动到下一个屏幕。但是，当我测试它时，应用程序崩溃，我得到错误，“未处理的事件循环异常”。 这是我的代码：

package com.example.trivia;

import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.text.Editable;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;


public class MainActivity extends Activity {

public static int players;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    //locates widgets
    Button submit = (Button) findViewById(R.id.submitPlayers);
    final EditText howMany = (EditText) findViewById(R.id.editText1);

    submit.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            //gets number of players from text field then goes to next activity
            players = Integer.parseInt(howMany.getText().toString());

            Intent intent = new Intent(v.getContext(), PlayerMenu.class);
            startActivityForResult(intent, 0);

        }
    });
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

}

另外，这是stacktrace：

eclipse.buildId=4.3.0.I20130605-2000
java.version=1.7.0_60
java.vendor=Oracle Corporation
BootLoader constants: OS=win32, ARCH=x86, WS=win32, NL=en_US
Framework arguments:  -product org.eclipse.epp.package.standard.product
Command-line arguments:  -os win32 -ws win32 -arch x86 -product               org.eclipse.epp.package.standard.product

Error
Sat Oct 25 10:12:03 CDT 2014
Unhandled event loop exception

org.eclipse.swt.SWTException: Failed to execute runnable (java.lang.NullPointerException)
    at org.eclipse.swt.SWT.error(SWT.java:4397)
    at org.eclipse.swt.SWT.error(SWT.java:4312)
    at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:138)
    at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:4145)
    at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3762)
    at     org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$9.run(PartRenderingEngine.java:1113)
    at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
     at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:997)
    at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:138)
    at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:610)
    at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
    at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:567)
    at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:150)
    at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:124)
    at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
    at     org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:354)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:181)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:636)
    at org.eclipse.equinox.launcher.Main.basicRun(Main.java:591)
    at org.eclipse.equinox.launcher.Main.run(Main.java:1450)
Caused by: java.lang.NullPointerException
    at com.android.ddmuilib.logcat.LogCatPanel.deviceSelected(LogCatPanel.java:364)
    at com.android.ddmuilib.SelectionDependentPanel.deviceSelected(SelectionDependentPanel.java:52)
    at c     om.android.ide.eclipse.ddms.views.SelectionDependentViewPart.selectionChanged(SelectionDependentViewPart.java:69)
     at com.android.ide.eclipse.ddms.LogCatMonitor$4.run(LogCatMonitor.java:217)
     at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)
    at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:135)
     .. 23 more