Java 单击按钮加载选项卡布局后应用程序崩溃
[编辑]当我尝试Sumant关于在意图构造函数中用“this”替换“v.getContext()”的建议时,Eclipse表示它无法构建应用程序。调用onClick()方法时,当前视图不是传递给它吗 [编辑2]我可能已经解决了这个问题。当我使用安卓2.3.3仿真器时,我可能使用的是安卓3.0的布局。要么就是这样,要么就是我只使用字符串数组而不是整数数组 在我的Android应用程序中,当用户单击按钮将他们带到选项卡式活动时,我正在运行的模拟器(使用Android 2.3.3)会强制关闭我的应用程序。这是最初的活动 dungeonsdragonsapactivity.java文件Java 单击按钮加载选项卡布局后应用程序崩溃,java,android,xml,arrays,button,Java,Android,Xml,Arrays,Button,[编辑]当我尝试Sumant关于在意图构造函数中用“this”替换“v.getContext()”的建议时,Eclipse表示它无法构建应用程序。调用onClick()方法时,当前视图不是传递给它吗 [编辑2]我可能已经解决了这个问题。当我使用安卓2.3.3仿真器时,我可能使用的是安卓3.0的布局。要么就是这样,要么就是我只使用字符串数组而不是整数数组 在我的Android应用程序中,当用户单击按钮将他们带到选项卡式活动时,我正在运行的模拟器(使用Android 2.3.3)会强制关闭我的应用程
package com.androidGuy.DnDApp;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import android.util.Log;
public class DungeonsDragonsAppActivity extends Activity {
/* Use this for debugging. */
private static final String DEBUG_TAG = "DnDAppDebugLogging";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
/* The main buttons... Yeah. */
final Button create_character_button = (Button) findViewById(R.id.createCharacterButton);
final Button open_character_button = (Button) findViewById(R.id.openCharacterButton);
final Button retrieve_character_button = (Button) findViewById(R.id.RetrieveCharacterButton);
/* The button for actually creating the character.. */
create_character_button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
try {
Intent intent = new Intent(v.getContext(),
CreateCharacterTabsActivity.class);
startActivityForResult(intent, 0);
} catch (Exception e) {
Log.e(DEBUG_TAG, "Click failed", e);
}
}
});
/* The button for opening a pre-existing character. */
open_character_button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Toast.makeText(DungeonsDragonsAppActivity.this,
"You will be able to open a character... Eventually.",
Toast.LENGTH_SHORT).show();
}
});
/* The button for importing from D & D insider. */
retrieve_character_button
.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Toast.makeText(
DungeonsDragonsAppActivity.this,
"You will be able to import characters... Hopefully.",
Toast.LENGTH_SHORT).show();
}
}
);
}
}
当用户单击按钮创建新角色时,应加载此活动:
CreateCharacterTabsActivity.java
package com.androidGuy.DnDApp;
import android.app.TabActivity;
import android.os.Bundle;
import android.widget.TabHost;
import android.content.Intent;
public class CreateCharacterTabsActivity extends TabActivity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
TabHost tabHost = getTabHost();
TabHost.TabSpec spec;
Intent intent;
// Initialize a TabSpec for each tab and add it to the TabHost.
spec = tabHost.newTabSpec("scores");
spec.setContent(new Intent().setClass(this,
CharacterAbilityScoresActivity.class));
spec.setIndicator("Scores");
tabHost.addTab(spec);
intent = new Intent().setClass(this, CharacterClassActivity.class);
spec = tabHost.newTabSpec("classes");
spec.setContent(intent);
spec.setIndicator("Classes");
tabHost.addTab(spec);
tabHost.setCurrentTab(0);
}
}
package com.androidGuy.DnDApp;
import android.app.Activity;
import android.os.Bundle;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.Toast;
import android.view.View;
public class CharacterAbilityScoresActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.ability_score_spinners); // Set the scene.
ArrayAdapter adapter = ArrayAdapter.createFromResource(this, R.array.ability_scores, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
/* The ability score spinners */
Spinner strengthSpinner = (Spinner) findViewById(R.id.StrengthSpinner);
strengthSpinner.setAdapter(adapter);
strengthSpinner
.setOnItemSelectedListener(new abilityScoreListSelectedListener());
Spinner constitutionSpinner = (Spinner) findViewById(R.id.ConstitutionSpinner);
constitutionSpinner.setAdapter(adapter);
constitutionSpinner
.setOnItemSelectedListener(new abilityScoreListSelectedListener());
}
/* Now let's see what the user selects. */
class abilityScoreListSelectedListener implements OnItemSelectedListener {
public void onItemSelected(AdapterView<?> parent, View view, int pos,
long id) {
Toast.makeText(parent.getContext(),
"You selected an ability score. Way to go.",
Toast.LENGTH_LONG).show();
}
public void onNothingSelected(AdapterView parent) {
// Do nothing... For now.
}
}
}
package com.androidGuy.DnDApp;
import android.app.Activity;
import android.os.Bundle;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.TextView;
public class CharacterClassActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.cha_classes);
final RadioGroup classesButtons = (RadioGroup) findViewById(R.id.radioGroup1);
classesButtons
.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
public void onCheckedChanged(RadioGroup group, int checkedId) {
TextView leTextView = (TextView) findViewById(R.id.chooseClassTextView);
if (checkedId != -1) {
RadioButton rb = (RadioButton) findViewById(checkedId);
if (rb != null) {
leTextView.setText("You chose: " + rb.getText());
}
} else {
leTextView.setText("Choose your class");
}
}
});
}
}
它使用这个XML文件来呈现选项卡(我从一个Android开发教程中获取)
tabs.xml
<?xml version="1.0" encoding="utf-8"?>
<TabHost xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@android:id/tabhost"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="5dp">
<FrameLayout
android:id="@android:id/tabcontent"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:padding="5dp"
android:layout_weight="1">
</FrameLayout>
<TabWidget
android:id="@android:id/tabs"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="0">
</TabWidget>
</LinearLayout>
</TabHost>
cha_classes.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:id="@+id/linearLayout1" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" xmlns:android="http://schemas.android.com/apk/res/android">
<TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:textAppearance="?android:attr/textAppearanceLarge" android:text="Choose your class" android:id="@+id/chooseClassTextView"></TextView>
<RadioGroup android:id="@+id/radioGroup1" android:layout_width="wrap_content" android:layout_height="wrap_content">
<RadioButton android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/ClericClassButton" android:text="Cleric"></RadioButton>
<RadioButton android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/FighterClassButton" android:text="Fighter"></RadioButton>
<RadioButton android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/PaladinClassButton" android:text="Paladin"></RadioButton>
<RadioButton android:layout_width="wrap_content" android:text="Ranger" android:layout_height="wrap_content" android:id="@+id/RangerClassButton"></RadioButton>
<RadioButton android:layout_width="wrap_content" android:text="Rogue" android:layout_height="wrap_content" android:id="@+id/RogueClassButton"></RadioButton>
<RadioButton android:layout_width="wrap_content" android:text="Warlock" android:layout_height="wrap_content" android:id="@+id/WarlockClassButton"></RadioButton>
<RadioButton android:layout_width="wrap_content" android:text="Warlord" android:layout_height="wrap_content" android:id="@+id/WarlordClassButton"></RadioButton>
<RadioButton android:layout_width="wrap_content" android:text="Wizard" android:layout_height="wrap_content" android:id="@+id/WizardClassButton"></RadioButton>
</RadioGroup>
</LinearLayout>
感谢您提供的任何见解。在内部类中使用此时要小心!我经常犯这样的错误,通常是在将
上下文
传递给某个对象时犯的错误!
确保使用正确的语法访问“外部”
此
,例如MyOuterClass。此
您的清单中似乎定义了两个启动器活动:
...
<activity android:name=".DungeonsDragonsAppActivity"
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=".CreateCharacterTabsActivity" android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<action android:name="android.intent.category.LAUNCHER"></action>
</intent-filter>
</activity>
...
。。。
...
这可能会导致TabManager崩溃。create_character_button.setOnClickListener(新视图.OnClickListener(){public void onClick(视图v){try{Intent Intent=new Intent(这是CreateCharacterTabsActivity.class);startActivityForResult(intent,0);}catch(异常e){Log.e(DEBUG_标记,“Click failed”,e);}};并移除第二个启动器活动。mainfeast中应该只有一个启动器活动。
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
android:versionCode="1"
android:versionName="1.0" package="com.androidGuy.DnDApp">
<uses-sdk android:minSdkVersion="10" />
<application android:icon="@drawable/icon" android:label="@string/app_name">
<activity android:name=".DungeonsDragonsAppActivity"
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=".CreateCharacterTabsActivity" android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<action android:name="android.intent.category.LAUNCHER"></action>
</intent-filter>
</activity>
<activity android:name=".CharacterAbilityScoresActivity"></activity>
<activity android:name=".CharacterClassActivity"></activity>
</application>
</manifest>
ERROR/AndroidRuntime(363): FATAL EXCEPTION: main
ERROR/AndroidRuntime(363): java.lang.NullPointerException
ERROR/AndroidRuntime(363): at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:355)
ERROR/AndroidRuntime(363): at android.widget.ArrayAdapter.getView(ArrayAdapter.java:323)
ERROR/AndroidRuntime(363): at android.widget.AbsSpinner.onMeasure(AbsSpinner.java:192)
ERROR/AndroidRuntime(363): at android.view.View.measure(View.java:8313)
ERROR/AndroidRuntime(363): at android.widget.TableRow.getColumnsWidths(TableRow.java:308)
ERROR/AndroidRuntime(363): at android.widget.TableLayout.findLargestCells(TableLayout.java:500)
ERROR/AndroidRuntime(363): at android.widget.TableLayout.measureVertical(TableLayout.java:465)
ERROR/AndroidRuntime(363): at android.widget.TableLayout.onMeasure(TableLayout.java:431)
ERROR/AndroidRuntime(363): at android.view.View.measure(View.java:8313)
ERROR/AndroidRuntime(363): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138)
ERROR/AndroidRuntime(363): at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1017)
ERROR/AndroidRuntime(363): at android.widget.LinearLayout.measureHorizontal(LinearLayout.java:701)
ERROR/AndroidRuntime(363): at android.widget.LinearLayout.onMeasure(LinearLayout.java:311)
ERROR/AndroidRuntime(363): at android.view.View.measure(View.java:8313)
ERROR/AndroidRuntime(363): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138)
ERROR/AndroidRuntime(363): at android.widget.FrameLayout.onMeasure(FrameLayout.java:250)
ERROR/AndroidRuntime(363): at android.view.View.measure(View.java:8313)
ERROR/AndroidRuntime(363): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138)
ERROR/AndroidRuntime(363): at android.widget.FrameLayout.onMeasure(FrameLayout.java:250)
ERROR/AndroidRuntime(363): at android.view.View.measure(View.java:8313)
ERROR/AndroidRuntime(363): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138)
ERROR/AndroidRuntime(363): at android.widget.FrameLayout.onMeasure(FrameLayout.java:250)
ERROR/AndroidRuntime(363): at android.view.View.measure(View.java:8313)
ERROR/AndroidRuntime(363): at android.widget.LinearLayout.measureVertical(LinearLayout.java:531)
ERROR/AndroidRuntime(363): at android.widget.LinearLayout.onMeasure(LinearLayout.java:309)
ERROR/AndroidRuntime(363): at android.view.View.measure(View.java:8313)
ERROR/AndroidRuntime(363): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138)
ERROR/AndroidRuntime(363): at android.widget.FrameLayout.onMeasure(FrameLayout.java:250)
ERROR/AndroidRuntime(363): at android.view.View.measure(View.java:8313)
ERROR/AndroidRuntime(363): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138)
ERROR/AndroidRuntime(363): at android.widget.FrameLayout.onMeasure(FrameLayout.java:250)
ERROR/AndroidRuntime(363): at android.view.View.measure(View.java:8313)
ERROR/AndroidRuntime(363): at android.widget.LinearLayout.measureVertical(LinearLayout.java:531)
ERROR/AndroidRuntime(363): at android.widget.LinearLayout.onMeasure(LinearLayout.java:309)
ERROR/AndroidRuntime(363): at android.view.View.measure(View.java:8313)
ERROR/AndroidRuntime(363): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138)
ERROR/AndroidRuntime(363): at android.widget.FrameLayout.onMeasure(FrameLayout.java:250)
ERROR/AndroidRuntime(363): at android.view.View.measure(View.java:8313)
ERROR/AndroidRuntime(363): at android.view.ViewRoot.performTraversals(ViewRoot.java:839)
ERROR/AndroidRuntime(363): at android.view.ViewRoot.handleMessage(ViewRoot.java:1859)
ERROR/AndroidRuntime(363): at android.os.Handler.dispatchMessage(Handler.java:99)
ERROR/AndroidRuntime(363): at android.os.Looper.loop(Looper.java:123)
ERROR/AndroidRuntime(363): at android.app.ActivityThread.main(ActivityThread.java:3683)
ERROR/AndroidRuntime(363): at java.lang.reflect.Method.invokeNative(Native Method)
ERROR/AndroidRuntime(363): at java.lang.reflect.Method.invoke(Method.java:507)
ERROR/AndroidRuntime(363): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
ERROR/AndroidRuntime(363): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
ERROR/AndroidRuntime(363): at dalvik.system.NativeStart.main(Native Method)
...
<activity android:name=".DungeonsDragonsAppActivity"
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=".CreateCharacterTabsActivity" android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<action android:name="android.intent.category.LAUNCHER"></action>
</intent-filter>
</activity>
...