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我正在学习 Android DEV。我正在尝试在http://developer.android.com/training/basics/firstapp/starting-activity.html#AddToManifest上构建第一个应用程序。

看起来我按照正确的说明进行操作。我的第一页出现了，但是当我写东西并单击“发送”消息时，第二页没有出现。

我真的很想在这里得到一些帮助。非常感谢您的帮助。

概括：

如教程中所述：

我的 mainactivity.java 看起来像这样：

package net.shm.helloworld;

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


public class MainActivity extends Activity {

    public final static String EXTRA_MESSAGE = "net.shm.helloworld.MESSAGE";

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

    @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;
    }

    public void sendMessage(View view) {
        // Do something in response to button
        Intent intent = new Intent(this, DisplayMessageActivity.class);
        EditText editText = (EditText) findViewById(R.id.edit_message);
        String message = editText.getText().toString();
        intent.putExtra(EXTRA_MESSAGE, message);
        startActivity(intent);

    }

}

第二个活动如下所示：

package net.shm.helloworld;

import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.support.v4.app.NavUtils;
import android.view.MenuItem;
import android.widget.TextView;

public class DisplayMessageActivity extends Activity {

    @SuppressLint("NewApi")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Get the message from the intent
        Intent intent = getIntent();
        String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);

        // Create the text view
        TextView textView = new TextView(this);
        textView.setTextSize(40);
        textView.setText(message);

        // Set the text view as the activity layout
        setContentView(textView);


        //setContentView(R.layout.activity_display_message);
        //Show the Up button in the action bar.
        //setupActionBar();


    }


    /**
     * Set up the {@link android.app.ActionBar}, if the API is available.
     */
    @TargetApi(Build.VERSION_CODES.HONEYCOMB)
    private void setupActionBar() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
            getActionBar().setDisplayHomeAsUpEnabled(true);
        }
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        case android.R.id.home:
            NavUtils.navigateUpFromSameTask(this);
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

}

我的 androidmenifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="net.shm.helloworld"
    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="net.shm.helloworld.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="net.shm.helloworld.DisplayMessageActivity"
            android:label="@string/title_activity_display_message"
            android:parentActivityName="net.shm.helloworld.MainActivity" >
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value="net.shm.helloworld.MainActivity" />
        </activity>
    </application>

</manifest>

我的activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal" >

     <EditText android:id="@+id/edit_message"
        android:layout_width="0dp"
        android:layout_weight="1"
        android:layout_height="wrap_content"
        android:hint="@string/edit_message" />

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



</LinearLayout>

我的第二个活动的布局文件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".DisplayMessageActivity" >


    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

</RelativeLayout>

我究竟做错了什么？

  • 吨
4

1 回答 1

1 
Activity 1:

Button sendMessage = (Button)findViewbyId(buttonId);
sendMessage.setOnClicListener(this);

public void click(View view){

EditText getText = (EditText)findViewbyId(edittextId);
String gettexts = getText.getText().toString();
Intent intent = new Intent(this, DisplayMessageActivity.class);
intent.putExtra("key", gettexts);
startActivity(intent);
}

Activity 2:
String getintenttext = getIntent().getString().get("key");

这是您必须将字符串一项活动转移到其他活动的方式。

于 2013-09-20T19:11:35.940 回答