9
不知道爲什麼我在下面的代碼中得到一個ClassCastException。將ListActivity更改爲Activity可以糾正錯誤，但我希望ListActivity，因爲這是我嘗試構建的更大代碼的一部分。任何幫助將不勝感激。由於java.lang.ClassCastException：android.widget.LinearLayout不能轉換爲android.widget.ListView
MainActivity.java
package com.example.debug;
import android.app.ListActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
public class MainActivity extends ListActivity {
@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;
}
@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);
}
}
activity_main.xml中：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@android:id/list"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<!-- Name Label -->
<TextView
android:id="@+id/vehicleType"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textColor="#43bd00"
android:textSize="16sp"
android:textStyle="bold"
android:paddingTop="6dip"
android:text="Mobile1"
android:paddingBottom="2dip" />
<!-- Description Label -->
<TextView
android:id="@+id/vehicleColor"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textColor="#acacac"
android:text="Mobile2"
android:paddingBottom="2dip" />
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<!-- Cost Label -->
<TextView
android:id="@+id/fuel"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#000000"
android:gravity="left"
android:textStyle="bold"
android:text="Mobile3" />
<!-- Price Label -->
<TextView
android:id="@+id/treadType"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#acacac"
android:text="Mobile4"
android:paddingBottom="2dip" />
</LinearLayout>
</LinearLayout>
<ListView
android:id="@android:id/list"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</ListView>
</LinearLayout>
堆棧跟蹤
FATAL EXCEPTION: main
Process: com.example.debug, PID: 1370
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.debug/com.example.debug.MainActivity}: java.lang.ClassCastException: android.widget.LinearLayout cannot be cast to android.widget.ListView
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.ClassCastException: android.widget.LinearLayout cannot be cast to android.widget.ListView
at android.app.ListActivity.onContentChanged(ListActivity.java:241)
at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:293)
at android.app.Activity.setContentView(Activity.java:1929)
at com.example.debug.MainActivity.onCreate(MainActivity.java:14)
at android.app.Activity.performCreate(Activity.java:5231)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
... 11 more