android开发者网站崩溃的示例代码

时间:2012-06-18 16:26:26

标签: android android-intent

所以我刚开始使用android进行开发,并逐步在开发站点上实现了示例代码。

前几个工作正常,但我坚持意图。

我已经浏览了代码及其在开发者网站上的完整副本。那么为什么在startActivity(intent)活动发生变化时它会崩溃?

帮助!

这是第一个活动:::

package com.example.Trial;

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

public class TrialActivity extends Activity {
    /** Called when the activity is first created. */
    public final static String EXTRA_MESSAGE = "com.example.myapp.MESSAGE";
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }
    public void sendMessage(View view) { 
        // Do something in response to button 
        Intent intent = new Intent(this, DisaplyMessageActivity.class); 
        EditText editText = (EditText) findViewById(R.id.edit_message); 
        String message = editText.getText().toString(); 
        intent.putExtra(EXTRA_MESSAGE, message);
        startActivity(intent);
        }
    }

这是它所称的活动:

package com.example.Trial;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;

public class DisaplyMessageActivity extends Activity { 
    @Override public void onCreate(Bundle savedInstanceState) 
    {
    super.onCreate(savedInstanceState);
    Intent intent = getIntent(); 
    String message = intent.getStringExtra(TrialActivity.EXTRA_MESSAGE);
TextView textView = new TextView(this); 
textView.setTextSize(40);
textView.setText(message); 
setContentView(textView);
} }

这是main.xml ::

      <?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/edit_message"
        android:layout_weight="1"
        android:layout_width="match_parent"
        android:layout_height="0dip"
        android:hint="@string/edit_message" />

        <Button
        android:onClick="sendMessage"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/button_send" />

</LinearLayout>

这是string.xml :::

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="app_name">My First App</string>
    <string name="edit_message">Enter a message</string>
    <string name="button_send">Send</string>
</resources>

FATAL EXCEPTION追溯到::

06-18 21:30:51.377:E / AndroidRuntime(341):at com.example.Trial.TrialActivity.sendMessage(TrialActivity.java:23)

非常感谢

1 个答案:

答案 0 :(得分:0)

您的清单中是否包含DisplayMessageActivity了吗?您的主要活动应该有一个,其他活动也应该有一个条目:

    <activity
        android:name=".TrialActivity"
        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=".DisplayMessageActivity" >
    </activity>