这是主要活动的代码。我在addJoke（）方法中添加了TextView，但它没有出现在LinearLayout中。请解决。
package edu.calpoly.android.lab2;
import java.util.ArrayList;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnKeyListener;
import android.view.ViewGroup.LayoutParams;
import android.view.inputmethod.InputMethodManager;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.TextView;
public class AdvancedJokeList extends Activity {
private static int i=0;
//protected String m_strAuthorName;
protected ArrayList<Joke> m_arrJokeList=new ArrayList<Joke>();
//protected JokeListAdapter m_jokeAdapter;
/**
* ViewGroup used for maintaining a list of Views that each display Jokes.
**/
protected LinearLayout m_vwJokeLayout;
protected EditText m_vwJokeEditText;
protected Button m_vwJokeButton;
protected int m_nDarkColor;
protected int m_nLightColor;
/**
* Filter Options Submenu constants
*/
protected static final int FILTER_OPTIONS = 1;
protected static final int LIKE = Menu.FIRST + 1;
protected static final int DISLIKE = Menu.FIRST + 2;
protected static final int UNRATED = Menu.FIRST + 3;
protected static final int SHOW_ALL = Menu.FIRST + 4;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
initLayout();
String[] jokestring=getResources().getStringArray(R.array.jokeList);
for(String str : jokestring)
{
Joke j=new Joke();
j.setJoke(str);
addJoke(j);
}
initAddJokeListeners();
}
protected void addJokeImplementation(){
String strJoke=m_vwJokeEditText.getText().toString().trim();
if(!strJoke.equals(""))
{
Joke joke=new Joke();
joke.setJoke(strJoke);
addJoke(joke);
}
}
protected void initLayout() {
setContentView(R.layout.advanced);
m_vwJokeLayout=(LinearLayout)findViewById(R.id.jokeListViewGroup);
m_vwJokeEditText=(EditText)findViewById(R.id.newJokeEditText);
m_vwJokeButton=(Button)findViewById(R.id.addJokeButton);
}
protected void initAddJokeListeners() {
// TODO
m_vwJokeEditText.setOnKeyListener(new OnKeyListener(){
@Override
public boolean onKey(View v,int keyCOde, KeyEvent event){
if(event.getAction()==KeyEvent.ACTION_DOWN)
{
if(keyCOde==KeyEvent.KEYCODE_DPAD_CENTER)
{
addJokeImplementation();
}
}
return false;
}
});
m_vwJokeButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View view) {
//Implement code to add a new joke here...
addJokeImplementation();
}
});
}
protected void addJoke(Joke joke) {
if(!m_arrJokeList.contains(joke))
{
m_arrJokeList.add(joke);
//I also added textview here this one also
//doesn't appear in Emulator layout, wondering whats wrong?;
TextView TV=new TextView(this);
TV.setLayoutParams(new LayoutParams(
LayoutParams.FILL_PARENT,
LayoutParams.WRAP_CONTENT));
TV.setText(joke.toString());
m_vwJokeLayout.addView(TV);
m_nDarkColor=getResources().getColor(R.color.dark);
m_nLightColor=getResources().getColor(R.color.light);
if(i==0)
{
TV.setBackgroundColor(m_nLightColor);
i=1;
}
else
{
TV.setBackgroundColor(m_nDarkColor);
i=0;
}
m_vwJokeEditText.setText("");
InputMethodManager imm = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(m_vwJokeEditText.getWindowToken(), 0);
}
}
/**
* Method used to retrieve Jokes from online server. The getJoke script
* takes a single optional parameter, which should be encode in "UTF-8".
* This parameter allows tells script to only retrieve Jokes whose author
* name matches the value in the parameter.
*
* param-1) "author": The author of the joke.
*
* URL: http://simexusa.com/aac/getJokes.php?
*
*/
protected void getJokesFromServer() {
// TODO
}
/**
* This method uploads a single Joke to the server. This method should test
* the response from the server and display success or failure to the user
* via a Toast Notification
*
* The addJoke script on the server requires two parameters, both of which
* should be encode in "UTF-8":
*
* param-1) "joke": The text of the joke.
*
* param-2) "author": The author of the joke.
*
* URL: http://simexusa.com/aac/addJoke.php?
*
* @param joke
* The Joke to be uploaded to the server.
*
*/
protected void uploadJokeToServer(Joke joke) {
// TODO
}
}
这是advanced.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="wrap_content"
>
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>
<Button
android:id="@+id/addJokeButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Add Joke"
/>
<EditText
android:id="@+id/newJokeEditText"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:hint="Enter Joke"
/>
</LinearLayout>
<LinearLayout
android:id="@+id/jokeListViewGroup"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>
</LinearLayout>
</LinearLayout>
更新：修改了一点代码，添加了Layout.params（）但仍然没有出现TextView。
答案 0 :(得分：0)
两个原因;您需要直接或使用布局参数设置电视视图的高度和宽度，然后在完成此操作后，您需要再次调用setContentView，但是因为添加它的布局是根布局的子级，您可能需要获取对根布局的引用，然后将TV视图添加到相应的子布局，然后将setContentView（根布局）添加。
答案 1 :(得分：0)
如果您想检查 您的视图是否存在，您将很乐意使用Hierarchy-viewer。检查一下：http://developer.android.com/guide/developing/tools/hierarchy-viewer.html
它会显示所有存在的视图以及它们的放置方式。对于这样的调试，这应该对你有很大的帮助！
答案 2 :(得分：0)
问题解决了......
我非常愚蠢....这太傻了...... 我忘了为根元素添加android：orientation =“vertical”。查看代码。
我已经习惯了Stackoverflow ....我变得很懒惰
感谢所有优秀的开发人员，每当我提出问题时，他们会给出一些好的提示以及答案。