Android.com的基本应用程序不会在应用程序

Question

中显示DisplayMessageActivity，因此我正在构建基本的应用程序教程，但我无法让DisplayActivityMessage类在应用程序本身中工作。当我输入文本并按下“发送”按钮时，我没有任何错误，没有任何反应。

继承人我的类和xmls。

MainActivity.java

package com.example.nan.joro2; 

import android.support.v7.app.ActionBarActivity; 
import android.os.Bundle; 
import android.view.Menu; 
import android.view.MenuItem; 
import android.content.Intent; 
import android.view.View; 
import android.widget.EditText; 
import android.widget.TextView; 




public class MainActivity extends ActionBarActivity { 
    public final static String EXTRA_MESSAGE = "com.example.nan.joro2.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.menu_main, menu); 
     return true; 
    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     // Handle action bar item clicks here. The action bar will 
     // automatically handle clicks on the Home/Up button, so long 
     // as you specify a parent activity in AndroidManifest.xml. 
     int id = item.getItemId(); 

     //noinspection SimplifiableIfStatement 
     if (id == R.id.action_settings) { 
      return true; 
     } 

     return super.onOptionsItemSelected(item); 
    } 
    //virker når brugeren trykker på knappen 
    public void sendMessage(View view){ 
     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); 
    } 
} 

DisplayMessageActivity.java

package com.example.nan.joro2; 

import android.content.Intent; 
import android.support.v7.app.ActionBarActivity; 
import android.os.Bundle; 
import android.view.Menu; 
import android.view.MenuItem; 
import android.widget.TextView; 


public class DisplayMessageActivity extends ActionBarActivity { 

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

     Intent intent = getIntent(); 
     String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE); 

     TextView textView = new TextView(this); 
     textView.setTextSize(40); 

     textView.setText(message); 
     setContentView(textView); 


    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     // Handle action bar item clicks here. The action bar will 
     // automatically handle clicks on the Home/Up button, so long 
     // as you specify a parent activity in AndroidManifest.xml. 
     int id = item.getItemId(); 

     //noinspection SimplifiableIfStatement 
     if (id == R.id.action_settings) { 
      return true; 
     } 

     return super.onOptionsItemSelected(item); 
    } 
} 

的AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?> 
    <manifest xmlns:android="http://schemas.android.com/apk/res/android" 
     package="com.example.nan.joro2" > 

     <application 
      android:allowBackup="true" 
      android:icon="@mipmap/ic_launcher" 
      android:label="@string/app_name" 
      android:theme="@style/AppTheme" > 
      <activity 
       android:name=".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=".DisplayMessageActivity" 
       android:label="@string/title_activity_display_message" 
       android:parentActivityName=".MainActivity" > 
       <meta-data 
        android:name="android.support.PARENT_ACTIVITY" 
        android:value="com.example.nan.joro2.MainActivity" /> 
      </activity> 
     </application> 

    </manifest> 

的strings.xml

<resources> 
    <string name="app_name">Joro2</string> 
    <string name="edit_message">Enter a message</string> 
    <string name="button_send">Send</string> 
    <string name="action_settings">Settings</string> 
    <string name="title_activity_main">MainActivity</string> 
    <string name="title_activity_display_message">My Message</string> 

    <string name="hello_world">Hello world!</string> 
</resources> 

activity_main.xml中

<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" 

    > 

    <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> 

Answer 1

添加startActivity（意向）;在sendMessage（）方法中