Java Android应用程序启动时崩溃
我刚刚开始android应用程序开发。当打开下面的应用程序时,它会说“不幸的是,你的应用程序崩溃了”。有人能指出这段代码中的错误吗 fragmentmain.xmlJava Android应用程序启动时崩溃,java,android,Java,Android,我刚刚开始android应用程序开发。当打开下面的应用程序时,它会说“不幸的是,你的应用程序崩溃了”。有人能指出这段代码中的错误吗 fragmentmain.xml <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:
<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:background="#ffffbb"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin" >
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="85dp"
android:text="Info of Departments and Student Bodies"
android:textAppearance="?android:attr/textAppearanceLarge" />
<ListView
android:id="@+id/listView"
android:layout_width="match_parent"
android:layout_height="190dp" >
</ListView>
</LinearLayout>
MainActivity.java
public class MainActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//adding items to list view
final ListView listview = (ListView) findViewById(R.id.listView);
String values[] = new String[]{"Departments" , "Student_bodies"};
final ArrayList<String> list = new ArrayList<String>();
for (int i=0 ; i < values.length; ++i){
list.add(values[i]);
}
ArrayAdapter<String> ap = new ArrayAdapter<String> (this,android.R.layout.simple_list_item_1,values);
listview.setAdapter(ap);
listview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
if (((TextView)arg1).getText().toString() == "Departments"){
startActivity(new Intent(MainActivity.this,Departments.class));
}
if (((TextView)arg1).getText().toString() == "Student_bodies"){
startActivity(new Intent(MainActivity.this,Student_bodies.class));
}
}
});
}
@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;
}
@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();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
}
}
公共类MainActivity扩展了ActionBarActivity{
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//将项目添加到列表视图
最终ListView ListView=(ListView)findViewById(R.id.ListView);
字符串值[]=新字符串[]{“部门”、“学生会”};
最终ArrayList=新ArrayList();
对于(int i=0;i
这只是列表视图的简单实现,并在其元素上实现
onClick()
以转到不同的活动
。感谢有人指出错误。您的布局文件名为FragmentMain
,但您使用Activity\u main
作为setContentView()
方法的参数。尝试更改为setContentView(R.layout.FragmentMain)代码>请从onCreate()中删除代码并添加到onCreateView(),因为您正在使用片段。
您的listview也在fragment_main.xml中定义
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
final ListView listview = (ListView) rootView.findViewById(R.id.listView);
String values[] = new String[]{"Departments" , "Student_bodies"};
final ArrayList<String> list = new ArrayList<String>();
for (int i=0 ; i < values.length; ++i){
list.add(values[i]);
}
ArrayAdapter<String> ap = new ArrayAdapter<String> (this,android.R.layout.simple_list_item_1,values);
listview.setAdapter(ap);
listview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
if (((TextView)arg1).getText().toString() == "Departments"){
startActivity(new Intent(MainActivity.this,Departments.class));
}
if (((TextView)arg1).getText().toString() == "Student_bodies"){
startActivity(new Intent(MainActivity.this,Student_bodies.class));
}
}
});
return rootView;
}
@覆盖
创建视图上的公共视图(布局、充气机、视图组容器、,
Bundle savedInstanceState){
视图根视图=充气机。充气(R.layout.fragment_main,容器,错误);
最终ListView ListView=(ListView)rootView.findViewById(R.id.ListView);
字符串值[]=新字符串[]{“部门”、“学生会”};
最终ArrayList=新ArrayList();
对于(int i=0;i
您可以发布您的日志猫吗?需要您的日志猫。您应该在Placeholder Fragment中重写onViewCreate,并将所有与listview相关的逻辑移到该方法中。至少你的应用程序不会在启动时崩溃。我不知道它为什么会崩溃,但你不能使用==((TextView)arg1)比较字符串。getText().toString()==“Departments”
使用.equals()
方法insted@user3696330您可以扩展活动并删除所有额外代码。如果项目中不需要片段概念,请将listview放在activity_main.xml中。错误。。。他正在使用活动
。他已经从ActionBarActivity
扩展到了先生,请检查他的xml及其实际使用的位置。哦,对了。。。很抱歉谢谢你的建议。我的应用程序在这次更改后正常工作