Java 如何将一个活动中的参数传递给另一个活动？
我在listview中根据从一个活动到另一个活动的单击传递参数。它在传递参数行的日志cat中显示错误 firs activity.javaJava 如何将一个活动中的参数传递给另一个活动？,java,android,Java,Android,我在listview中根据从一个活动到另一个活动的单击传递参数。它在传递参数行的日志cat中显示错误 firs activity.java public class SouthIndianvegrecipes1 extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState);
public class SouthIndianvegrecipes1 extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ArrayList<Recipedetails> image_details = GetSearchResults();
final ListView lv1 = (ListView) findViewById(R.id.listV_main);
lv1.setAdapter(new ItemListBaseAdapter(this, image_details));
lv1.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> a, View v, int position, long id) {
Object o = lv1.getItemAtPosition(position);
Recipedetails obj_itemDetails = (Recipedetails)o;
Toast.makeText(SouthIndianvegrecipes1.this, "You have chosen : " + " " + obj_itemDetails.getName(), Toast.LENGTH_LONG).show();
Intent newActivity = new Intent(SouthIndianvegrecipes1.this,
SouthIndianvegmanualrecipes.class );
newActivity.putExtra("name", obj_itemDetails.getName());
startActivity(newActivity);
}
});
}
private ArrayList<Recipedetails> GetSearchResults(){
ArrayList<Recipedetails> results = new ArrayList<Recipedetails>();
Recipedetails item_details = new Recipedetails();
item_details.setName("Godhumai veg adai");
item_details.setItemDescription("This is very good for dibets people");
//item_details.setUrlWiki("https://www.youtube.com/watch?v=C_r0mFvMSfU");
item_details.setImageNumber(12);
results.add(item_details);
item_details = new Recipedetails();
item_details.setName("Soyamore koozh");
item_details.setItemDescription("Tasty to have this as main dish");
//item_details.setUrlWiki("https://www.youtube.com/watch?v=C_r0mFvMSfU");
item_details.setImageNumber(13);
results.add(item_details);
item_details = new Recipedetails();
item_details.setName("Tomato kulambu");
item_details.setItemDescription("Good side dish for rice and dinner");
//item_details.setUrlWiki("https://www.youtube.com/watch?v=C_r0mFvMSfU");
item_details.setImageNumber(14);
results.add(item_details);
item_details = new Recipedetails();
item_details.setName("Tomato upma");
item_details.setItemDescription("Evening time dinner for kids");
//item_details.setUrlWiki("https://www.youtube.com/watch?v=C_r0mFvMSfU");
item_details.setImageNumber(15);
results.add(item_details);
item_details = new Recipedetails();
item_details.setName("Navratri special vada");
item_details.setItemDescription("Good snacks at the function");
//item_details.setUrlWiki("https://www.youtube.com/watch?v=C_r0mFvMSfU");
item_details.setImageNumber(16);
results.add(item_details);
item_details = new Recipedetails();
item_details.setName("Egg kurma");
item_details.setItemDescription("Wonderful dish made by egg");
//item_details.setUrlWiki("https://www.youtube.com/watch?v=C_r0mFvMSfU");
item_details.setImageNumber(17);
results.add(item_details);
item_details = new Recipedetails();
item_details.setName("Milagu kuzhambu");
item_details.setItemDescription("Good for digestion purpose");
//item_details.setUrlWiki("https://www.youtube.com/watch?v=C_r0mFvMSfU");
item_details.setImageNumber(18);
results.add(item_details);
item_details = new Recipedetails();
item_details.setName("Rasam");
item_details.setItemDescription("Last and famous dish in lunch,good for health also");
//item_details.setUrlWiki("https://www.youtube.com/watch?v=C_r0mFvMSfU");
item_details.setImageNumber(19);
results.add(item_details);
item_details = new Recipedetails();
item_details.setName("Vegetable kootu");
item_details.setItemDescription("Nice and healthy one");
//item_details.setUrlWiki("https://www.youtube.com/watch?v=C_r0mFvMSfU");
item_details.setImageNumber(20);
results.add(item_details);
item_details = new Recipedetails();
item_details.setName("Avial");
item_details.setItemDescription("Easy to prepare and lots of vegetable");
//item_details.setUrlWiki("https://www.youtube.com/watch?v=C_r0mFvMSfU");
item_details.setImageNumber(21);
results.add(item_details);
item_details = new Recipedetails();
item_details.setName("kothavarangaicurry");
item_details.setItemDescription("Tamilnadu special and healthy too");
//item_details.setUrlWiki("https://www.youtube.com/watch?v=C_r0mFvMSfU");
item_details.setImageNumber(22);
results.add(item_details);
return results;
}
}
passing the arguments after toasting ,passing their names
second activity.java
public class SouthIndianvegmanualrecipes extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.recipe_manual);
}
String value =null;
Bundle extras = getIntent().getExtras();
{
if (extras != null) {
if (extras.containsKey("name")) {
value = extras.getString("name");
}
}
{
//int obj_itemDetails.getImageNumber() = extras.getIntArray("numbers");
//private ArrayList<Recipedetails2> GetSearchResults(){
//ArrayList<Recipedetails2> results = new ArrayList<Recipedetails2>();
if(value.equals("Godhumai veg adai"))
{
Recipedetails2 item_details = new Recipedetails2();
item_details.setName("Godhumai veg adai");
item_details.setIngredients("This is very good for dibets people");
item_details.setMethods("This is very good for dibets people");
}
else if(value.equals("Soyamore koozh"))
{
Recipedetails2 item_detail1 = new Recipedetails2();
item_detail1.setName("Soyamore koozh");
item_detail1.setIngredients("Tasty to have this as main dish");
item_detail1.setMethods("This is very good for dibets people");
}
else if(value.equals("Tomato kulambu"))
{
Recipedetails2 item_detail3 = new Recipedetails2();
item_detail3.setName("Tomato kulambu");
item_detail3.setIngredients("Good side dish for rice and dinner");
item_detail3.setMethods("This is very good for dibets people");
}
else if(value.equals("Navratri special vada"))
{
Recipedetails2 item_detail5 = new Recipedetails2();
item_detail5.setName("Navratri special vada");
item_detail5.setIngredients("Good snacks at the function");
item_detail5.setMethods("This is very good for dibets people");
}
else if(value.equals("Egg kurma"))
{
Recipedetails2 item_detail6 = new Recipedetails2();
item_detail6.setName("Egg kurma");
item_detail6.setIngredients("Wonderful dish made by egg");
item_detail6.setMethods("This is very good for dibets people");
}
else if(value.equals("Milagu kuzhambu"))
{
Recipedetails2 item_detail7 = new Recipedetails2();
item_detail7.setName("Milagu kuzhambu");
item_detail7.setIngredients("Good for digestion purpose");
item_detail7.setMethods("This is very good for dibets people");
}
else if(value.equals("Rasam"))
{
Recipedetails2 item_detail8 = new Recipedetails2();
item_detail8.setName("Rasam");
item_detail8.setIngredients("Last and famous dish in lunch,good for health also");
item_detail8.setMethods("This is very good for dibets people");
}
else if(value.equals("Vegetable kootu"))
{
Recipedetails2 item_detail9 = new Recipedetails2();
item_detail9.setName("Vegetable kootu");
item_detail9.setIngredients("Nice and healthy one");
item_detail9.setMethods("This is very good for dibets people");
}
else if(value.equals("Avial"))
{
Recipedetails2 item_detail10 = new Recipedetails2();
item_detail10.setName("Avial");
item_detail10.setIngredients("Easy to prepare and lots of vegetable");
item_detail10.setMethods("This is very good for dibets people");
}
else
{
Recipedetails2 item_detail11 = new Recipedetails2();
item_detail11.setName("kothavarangaicurry");
item_detail11.setIngredients("Tamilnadu special and healthy too");
item_detail11.setMethods("This is very good for dibets people");
}
}
}
公共类SouthIndianvegrecipes1扩展活动{
@凌驾
创建时的公共void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.main）；
ArrayList image_details=GetSearchResults（）；
最终ListView lv1=（ListView）findViewById（R.id.listV_main）；
lv1.setAdapter（新的ItemListBaseAdapter（这个，图片_详细信息））；
lv1.setOnItemClickListener（新的OnItemClickListener（）{
@凌驾
public void onItemClick（适配器视图a、视图v、内部位置、长id）{
对象o=lv1.getItemAtPosition（位置）；
RecipedDetails obj_itemDetails=（RecipedDetails）o；
Toast.makeText（SouthIndianvegrecipes1.this，“您已选择：”+“”+obj_itemDetails.getName（），Toast.LENGTH_LONG.show（）；
意向新活动=新意向（南印度群岛），
南印度群岛素食手册菜谱.class）；
newActivity.putExtra（“name”，obj_itemDetails.getName（））；
星触觉（新活动）；
}
});
}
私有ArrayList GetSearchResults（）{
ArrayList结果=新建ArrayList（）；
RecipedDetails item_details=新RecipedDetails（）；
项目详细信息。设置名称（“Godhumai veg adai”）；
item_details.setItemDescription（“这对dibets人来说非常好”）；
//项目_详细信息。setUrlWiki（“https://www.youtube.com/watch?v=C_r0mFvMSfU");
项目_详情。设置图像编号（12）；
结果。添加（项目详情）；
项目_详情=新的RecipedDetails（）；
项目_详情。设置名称（“Soyamore koozh”）；
项目详细信息。setItemDescription（“将此作为主菜很美味”）；
//项目_详细信息。setUrlWiki（“https://www.youtube.com/watch?v=C_r0mFvMSfU");
项目_详情。设置图像编号（13）；
结果。添加（项目详情）；
项目_详情=新的RecipedDetails（）；
项目_详情。设置名称（“番茄库兰布”）；
项目_详情。setItemDescription（“米饭和晚餐的好配菜”）；
//项目_详细信息。setUrlWiki（“https://www.youtube.com/watch?v=C_r0mFvMSfU");
项目_详情。设置图像编号（14）；
结果。添加（项目详情）；
项目_详情=新的RecipedDetails（）；
项目_详情。设置名称（“番茄upma”）；
item_details.setItemDescription（“晚间儿童晚餐”）；
//项目_详细信息。setUrlWiki（“https://www.youtube.com/watch?v=C_r0mFvMSfU");
项目_详情。设置图像编号（15）；
结果。添加（项目详情）；
项目_详情=新的RecipedDetails（）；
项目_详情。设置名称（“Navratri特殊vada”）；
item_details.setItemDescription（“活动中的好零食”）；
//项目_详细信息。setUrlWiki（“https://www.youtube.com/watch?v=C_r0mFvMSfU");
项目_详情。设置图像编号（16）；
结果。添加（项目详情）；
项目_详情=新的RecipedDetails（）；
项目_详情。设置名称（“蛋库”）；
项目_详情。setItemDescription（“鸡蛋做的绝妙菜肴”）；
//项目_详细信息。setUrlWiki（“https://www.youtube.com/watch?v=C_r0mFvMSfU");
项目_详情。设置图像编号（17）；
结果。添加（项目详情）；
项目_详情=新的RecipedDetails（）；
项目_详情。设置名称（“Milagu kuzhambu”）；
项目_详情。setItemDescription（“用于消化目的”）；
//项目_详细信息。setUrlWiki（“https://www.youtube.com/watch?v=C_r0mFvMSfU");
项目_详情。设置图像编号（18）；
结果。添加（项目详情）；
项目_详情=新的RecipedDetails（）；
项目_详情。设置名称（“Rasam”）；
item_details.setItemDescription（“午餐中最后一道名菜，对健康也有好处”）；
//项目_详细信息。setUrlWiki（“https://www.youtube.com/watch?v=C_r0mFvMSfU");
项目_详情。设置图像编号（19）；
结果。添加（项目详情）；
项目_详情=新的RecipedDetails（）；
项目_详情。设置名称（“蔬菜库图”）；
item_details.setItemDescription（“漂亮健康的”）；
//项目_详细信息。setUrlWiki（“https://www.youtube.com/watch?v=C_r0mFvMSfU");
项目详细信息。设置图像编号（20）；
结果。添加（项目详情）；
项目_详情=新的RecipedDetails（）；
项目_详情。设置名称（“Avial”）；
item_details.setItemDescription（“易于准备和大量蔬菜”）；
//项目_详细信息。setUrlWiki（“https://www.youtube.com/watch?v=C_r0mFvMSfU");
项目_详情。设置图像编号（21）；
结果。添加（项目详情）；
项目_详情=新的RecipedDetails（）；
项目_详情。设置名称（“kothavarangaicurry”）；
项目_详情。setItemDescription（“泰米尔纳德邦特别健康”）；
//项目_详细信息。setUrlWiki（“https://www.youtube.com/watch?v=C_r0mFvMSfU");
项目_详情。设置图像编号（22）；
结果。添加（项目详情）；
返回结果；
}
}
干杯后传递争论，传递他们的名字
第二个activity.java
公共课南印度素食手册食谱扩展活动{
@凌驾
创建时的公共void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.recipe_手册）；
}
字符串值=null；
Bundle extras=getIntent（）.getExtras（）；
{
如果（附加值！=null）{
如果（额外的集装箱（“名称”））{
value=extras.getSt
03-08 04:52:09.754: E/AndroidRuntime(1048): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.recipestutors/com.example.recipestutors.SouthIndianvegmanualrecipes}: java.lang.NullPointerException
03-08 04:52:09.754: E/AndroidRuntime(1048): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2106)
03-08 04:52:09.754: E/AndroidRuntime(1048): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
03-08 04:52:09.754: E/AndroidRuntime(1048): at android.app.ActivityThread.access$600(ActivityThread.java:141)
03-08 04:52:09.754: E/AndroidRuntime(1048): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
03-08 04:52:09.754: E/AndroidRuntime(1048): at android.os.Handler.dispatchMessage(Handler.java:99)
03-08 04:52:09.754: E/AndroidRuntime(1048): at android.os.Looper.loop(Looper.java:137)
03-08 04:52:09.754: E/AndroidRuntime(1048): at android.app.ActivityThread.main(ActivityThread.java:5039)
03-08 04:52:09.754: E/AndroidRuntime(1048): at java.lang.reflect.Method.invokeNative(Native Method)
03-08 04:52:09.754: E/AndroidRuntime(1048): at java.lang.reflect.Method.invoke(Method.java:511)
03-08 04:52:09.754: E/AndroidRuntime(1048): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
03-08 04:52:09.754: E/AndroidRuntime(1048): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
03-08 04:52:09.754: E/AndroidRuntime(1048): at dalvik.system.NativeStart.main(Native Method)
03-08 04:52:09.754: E/AndroidRuntime(1048): Caused by: java.lang.NullPointerException
03-08 04:52:09.754: E/AndroidRuntime(1048): at com.example.recipestutors.SouthIndianvegmanualrecipes.<init>(SouthIndianvegmanualrecipes.java:79)
03-08 04:52:09.754: E/AndroidRuntime(1048): at java.lang.Class.newInstanceImpl(Native Method)
03-08 04:52:09.754: E/AndroidRuntime(1048): at java.lang.Class.newInstance(Class.java:1319)
03-08 04:52:09.754: E/AndroidRuntime(1048): at android.app.Instrumentation.newActivity(Instrumentation.java:1054)
03-08 04:52:09.754: E/AndroidRuntime(1048): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2097)
03-08 04:52:09.754: E/AndroidRuntime(1048): ... 11 more
String value =null;
Bundle extras = getIntent().getExtras();
if (extras != null) {
if (extras.containsKey("name")) {
value = extras.getString("name");
}
}
Bundle extras = getIntent().getExtras();
if (extras != null) {
if (extras.containsKey(PRODUCT_NAME)) {
value = extras.getString(PRODUCT_NAME);
}
}
public class SouthIndianvegmanualrecipes extends Activity {
private Object getIntent;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.recipe_manual);
String value =getIntent().getStringExtra("name");
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.recipe_manual);
Intent intent = getIntent();
String value = intent.getStringExtra("name");