初学android，第二个程序就是检查不出错！求解、、；错误弹出对话框显示stoped unexpected，
Android Launch!
[2012-03-13 16:42:29 - Activity_03] adb is running normally.
[2012-03-13 16:42:29 - Activity_03] Performing mars.Activity03.Activity03 activity launch
[2012-03-13 16:42:29 - Activity_03] Automatic Target Mode: using existing emulator 'emulator-5554' running compatible AVD 'android1.6'
[2012-03-13 16:42:34 - Activity_03] Application already deployed. No need to reinstall.
[2012-03-13 16:42:34 - Activity_03] Starting activity mars.Activity03.Activity03 on device emulator-5554
[2012-03-13 16:42:38 - Activity_03] ActivityManager: Starting: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] cmp=mars.Activity03/.Activity03 }
error：
E/AndroidRuntime(805): Uncaught handler: thread main exiting due to uncaught exception
(这个哪里会有异常？?)
03-13 08:50:03.854: E/AndroidRuntime(805): java.lang.RuntimeException: Unable to start activity ComponentInfo{mars.Activity03/mars.Activity03.ResultActivity}: java.lang.NumberFormatException: unable to parse 'null' as integer（我在两个框里输入的都是整数，怎么不能转了?)
Activity03.java内容如下:
- Java code
package mars.Activity03;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.*;public class Activity03 extends Activity { private EditText factorOne,factorTwo; private TextView symbol; private Button calculate; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); //根据控件的ID来取得代表控件的对象 factorOne=(EditText)findViewById(R.id.factorOne); factorTwo=(EditText)findViewById(R.id.factorTwo); symbol=(TextView)findViewById(R.id.symbol); calculate=(Button)findViewById(R.id.calculate); // symbol.setText("乘以"); //calculate.setText("计算"); symbol.setText(R.string.symbol); calculate.setText(R.string.calculate); calculate.setOnClickListener(new CalculateListener()); } class CalculateListener implements OnClickListener{ public void onClick(View arg0) { // TODO Auto-generated method stub //取得两个 String factorOneStr=factorOne.getText().toString(); String factorTwoStr=factorTwo.getText().toString(); Intent intent=new Intent(); intent.putExtra("one", factorOneStr); intent.putExtra("two", factorTwoStr); intent.setClass(Activity03.this, ResultActivity.class); Activity03.this.startActivity(intent); System.out.println("onClick--error"); } }}对应main.xml如下：
- XML code
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" ><EditText android:id="@+id/factorOne" android:layout_width="fill_parent" android:layout_height="wrap_content" /> <TextView android:id="@+id/symbol" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="@string/hello" /><EditText android:id="@+id/factorTwo" android:layout_width="fill_parent" android:layout_height="wrap_content" /><Button android:id="@+id/calculate" android:layout_width="fill_parent" android:layout_height="wrap_content" /></LinearLayout>
ResultActivity。java内容如下：
- Java code
package mars.Activity03;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.widget.TextView;public class ResultActivity extends Activity{ private TextView resultView=null; protected void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.result); System.out.println("resultActivity--error"); resultView=(TextView)findViewById(R.id.result); Intent intent=getIntent();System.out.println("哪里错哦了！！"); String factorOneStr=intent.getStringExtra("one"); String factorTwoStr=intent.getStringExtra("Two"); int factorOneInt=Integer.parseInt(factorOneStr); int factorTwoInt=Integer.parseInt(factorTwoStr); int result=factorOneInt*factorTwoInt; resultView.setText(result+""); System.out.println("哪里错哦了！！--最后"); }}对应result.xml如下:
- XML code
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" > <TextView android:id="@+id/result" android:layout_width="fill_parent" android:layout_height="wrap_content" /></LinearLayout>
string。xml如下：
- XML code
<?xml version="1.0" encoding="utf-8"?><resources> <string name="hello">Hello World, Activity03!</string> <string name="app_name">Activity03</string> <string name="resultLabel">ResultActivity</string> <string name="symbol">乘以</string> <string name="calculate">计算</string> </resources>
AndroidManifest.xml如下：
- XML code
<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android" package="mars.Activity03" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="4" /> <application android:icon="@drawable/ic_launcher" android:label="@string/app_name" > <activity android:name=".Activity03" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <activity android:name=".ResultActivity" android:label="@string/resultLabel"></activity> </application></manifest>
[解决办法]
看，这里的two是小写
intent.putExtra("two", factorTwoStr);
这里的Two第一个字母是大写，所以得不到值，为空。
String factorTwoStr=intent.getStringExtra("Two");
大、 小写是有区别的噢。
------解决方案--------------------
[解决办法]
4楼正解，楼主不仔细造成的