Question

我创建了一个打开另一个激活的按钮。当我运行我的应用程序时，它崩溃并说“不幸的是程序停止了”。可能有人发现错误。这是我的代码：

MainActivty：

package com.example.listview2;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.first);
        Button but = (Button) findViewById(R.id.but);

        but.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, ListActivity.class);
                startActivity(intent);
            }
        });

}
}

ListActivity：

package com.example.listview2;

import java.util.ArrayList;

import android.app.Activity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;

public class ListActivity extends Activity {
    private EditText etInput;
    private Button btnAdd;
    private ListView lvItem;
    private ArrayList<String> itemArrey;
    private ArrayAdapter<String> itemAdapter;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setUpView();

    }

    private void setUpView() {
        // TODO Auto-generated method stub
        etInput = (EditText)this.findViewById(R.id.editText_input);
        btnAdd = (Button)this.findViewById(R.id.button_add);
        lvItem = (ListView)this.findViewById(R.id.listView_items);


        itemArrey = new ArrayList<String>();
        itemArrey.clear();

        itemAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,itemArrey);
        lvItem.setAdapter(itemAdapter);


        btnAdd.setOnClickListener(new View.OnClickListener() {

            public void onClick(View v) {

                addItemList();
            }
        });

        etInput.setOnKeyListener(new View.OnKeyListener() {

            public boolean onKey(View v, int keyCode, KeyEvent event) {
                // TODO Auto-generated method stub

                if (keyCode == KeyEvent.KEYCODE_ENTER) {
                    addItemList();
                }
                return true;
            }
        });


    }

    protected void addItemList() {
        // TODO Auto-generated method stub

        // TODO Auto-generated method stub
    if (isInputValid(etInput)) {
        itemArrey.add(0,etInput.getText().toString());
        etInput.setText("");

        itemAdapter.notifyDataSetChanged();

    }   

    }

    protected boolean isInputValid(EditText etInput2) {
        // TODO Auto-generatd method stub
        if (etInput2.getText().toString().trim().length()<1) {
            etInput2.setError("Please Enter Item");
            return false;
        } else {
            return true;
        }

    }
}

清单：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.listview2"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.listview2.MainActivity"
            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="com.example.listview2.ListActivity"
             android:label="@string/app_name">    
        </activity>
    </application>

</manifest>

logcat的：

06-09 12:30:00.311: E/AndroidRuntime(2012):     at android.os.Handler.dispatchMessage(Handler.java:99)
06-09 12:30:00.311: E/AndroidRuntime(2012):     at android.os.Looper.loop(Looper.java:137)
06-09 12:30:00.311: E/AndroidRuntime(2012):     at android.app.ActivityThread.main(ActivityThread.java:5039)
06-09 12:30:00.311: E/AndroidRuntime(2012):     at java.lang.reflect.Method.invokeNative(Native Method)
06-09 12:30:00.311: E/AndroidRuntime(2012):     at java.lang.reflect.Method.invoke(Method.java:511)
06-09 12:30:00.311: E/AndroidRuntime(2012):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
06-09 12:30:00.311: E/AndroidRuntime(2012):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
06-09 12:30:00.311: E/AndroidRuntime(2012):     at dalvik.system.NativeStart.main(Native Method)
06-09 12:30:00.311: E/AndroidRuntime(2012): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.example.listview.FirstActivity" on path: /data/app/com.example.listview-2.apk
06-09 12:30:00.311: E/AndroidRuntime(2012):     at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:65)
06-09 12:30:00.311: E/AndroidRuntime(2012):     at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
06-09 12:30:00.311: E/AndroidRuntime(2012):     at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
06-09 12:30:00.311: E/AndroidRuntime(2012):     at android.app.Instrumentation.newActivity(Instrumentation.java:1054)
06-09 12:30:00.311: E/AndroidRuntime(2012):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2097)

Answer 1

系统找不到您正在呼叫的FirstActivity活动。您需要在manifest.xml

中声明所有活动

在清单中添加以下内容：

<activity android:name="com.example.listview.FirstActivity" />

Answer 2

清理并构建然后再次运行项目。你可以将ListActivity重命名为其他东西，就像blackbelt所说的那样。如果这不起作用，那么在Intent中给出完整的包名，然后就像

一样

Intent intent = new Intent(MainActivity.this, com.example.listview2.ListActivity.class);

OnClickListener错误程序停止

2 个答案: