启动活动时出错
error when startActivity
祝大家新年快乐。
我在使用 onItemClickListener 方法时遇到问题,因为当我尝试在我的第二个 activity 中对位置和 id 进行敬酒时,我得到了零。
这是代码,我依赖于图像在数组中的位置,这就是我需要准确获取 position/id 的原因。
+
我在这两个活动中都复制我的数组,因为我不知道如何从第二个活动中访问它activity?
MainActivity.java
package swe.trial;
import android.content.Context;
import android.widget.ImageView;
import android.view.View;
import android.view.ViewGroup;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.content.Intent;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.AdapterView;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
GridView items = (GridView) findViewById(R.id.itemsList);
items.setAdapter(new item_adapter(this));
items.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
//if an item is clicked or selceted,then go to the activity itemDetails:
Intent i= new Intent (MainActivity.this, itemDetails.class);
i.putExtra("position", position);
i.putExtra("id", id);
startActivity(i);
}
});
}
}
class item_adapter extends BaseAdapter {
Integer[] picsId = {
R.drawable.pic1,
R.drawable.pic2,
R.drawable.pic3,
R.drawable.pic4,
R.drawable.pic5,
R.drawable.pic6,
R.drawable.pic7};
private Context context;
public item_adapter(Context context) {
this.context = context;
}
public Object getItem(int position) {
return null;
}
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imgview= new ImageView(context);
imgview.setLayoutParams(new GridView.LayoutParams(250,250));
imgview.setScaleType(ImageView.ScaleType.CENTER_CROP);
imgview.setPadding(20,20,20,20);
imgview.setImageResource(picsId[position]);
return imgview;
}
public long getItemId(int position) {
return position;
}
public int getCount (){
return picsId.length;
}
}
itemDetails.java
package swe.trial;
import android.content.Context;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.content.Intent;
import android.widget.ImageView;
import android.widget.TextView;
import android.app.Activity;
import android.net.Uri;
import android.view.View;
import android.widget.Toast;
import java.util.ArrayList;
/**
* Created by good on 1/01/17.
*/
public class itemDetails extends AppCompatActivity {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.item);
ArrayList<item> items = new ArrayList<item>();
// items item1=
// Bundle d = getIntent().getExtras();
int id=0;getIntent().getIntExtra("id",id);
int position=0;
getIntent().getIntExtra("position", position);
Toast.makeText( this, "id= " +id + " . and posistion= "+ position, Toast.LENGTH_LONG).show();
Integer[] picsId = {
R.drawable.pic1,
R.drawable.pic2,
R.drawable.pic3,
R.drawable.pic4,
R.drawable.pic5,
R.drawable.pic6,
R.drawable.pic7
};
ImageView imgview = (ImageView) findViewById(R.id.item_image);
imgview.setImageResource(picsId[id+ 1]);
TextView txt= (TextView) findViewById(R.id.pricetxtview);
txt.setText("This is the description provided." + id);
//(id);
// item item1 = {"Red rose", "@/drawable/", 1, 1.25};
// items.add(item1);
// now i will search for the array that holds the given id. and i will retrieve its info and display it again
// in the new layout.
}
}
您必须按照以下方式取值,
int id=0;
int position=0;
i=getIntent().getIntExtra("id",id);
position= getIntent().getIntExtra("position", position);
Toast.makeText( this, "id= " +id + " . and posistion= "+ position, Toast.LENGTH_LONG).show();
您误解了应该使用 Intent 的方式。
正确的形式是这样的:
int id =getIntent().getIntExtra("id",0);
int position = getIntent().getIntExtra("position", 0);
当你使用getIntExtra
时,第二个参数是默认值。如果您的意图中该标签没有这样的值,它将 return 该默认值。
有关详细信息,请参阅 Google docs
祝大家新年快乐。 我在使用 onItemClickListener 方法时遇到问题,因为当我尝试在我的第二个 activity 中对位置和 id 进行敬酒时,我得到了零。 这是代码,我依赖于图像在数组中的位置,这就是我需要准确获取 position/id 的原因。 + 我在这两个活动中都复制我的数组,因为我不知道如何从第二个活动中访问它activity?
MainActivity.java
package swe.trial;
import android.content.Context;
import android.widget.ImageView;
import android.view.View;
import android.view.ViewGroup;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.content.Intent;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.AdapterView;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
GridView items = (GridView) findViewById(R.id.itemsList);
items.setAdapter(new item_adapter(this));
items.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
//if an item is clicked or selceted,then go to the activity itemDetails:
Intent i= new Intent (MainActivity.this, itemDetails.class);
i.putExtra("position", position);
i.putExtra("id", id);
startActivity(i);
}
});
}
}
class item_adapter extends BaseAdapter {
Integer[] picsId = {
R.drawable.pic1,
R.drawable.pic2,
R.drawable.pic3,
R.drawable.pic4,
R.drawable.pic5,
R.drawable.pic6,
R.drawable.pic7};
private Context context;
public item_adapter(Context context) {
this.context = context;
}
public Object getItem(int position) {
return null;
}
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imgview= new ImageView(context);
imgview.setLayoutParams(new GridView.LayoutParams(250,250));
imgview.setScaleType(ImageView.ScaleType.CENTER_CROP);
imgview.setPadding(20,20,20,20);
imgview.setImageResource(picsId[position]);
return imgview;
}
public long getItemId(int position) {
return position;
}
public int getCount (){
return picsId.length;
}
}
itemDetails.java
package swe.trial;
import android.content.Context;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.content.Intent;
import android.widget.ImageView;
import android.widget.TextView;
import android.app.Activity;
import android.net.Uri;
import android.view.View;
import android.widget.Toast;
import java.util.ArrayList;
/**
* Created by good on 1/01/17.
*/
public class itemDetails extends AppCompatActivity {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.item);
ArrayList<item> items = new ArrayList<item>();
// items item1=
// Bundle d = getIntent().getExtras();
int id=0;getIntent().getIntExtra("id",id);
int position=0;
getIntent().getIntExtra("position", position);
Toast.makeText( this, "id= " +id + " . and posistion= "+ position, Toast.LENGTH_LONG).show();
Integer[] picsId = {
R.drawable.pic1,
R.drawable.pic2,
R.drawable.pic3,
R.drawable.pic4,
R.drawable.pic5,
R.drawable.pic6,
R.drawable.pic7
};
ImageView imgview = (ImageView) findViewById(R.id.item_image);
imgview.setImageResource(picsId[id+ 1]);
TextView txt= (TextView) findViewById(R.id.pricetxtview);
txt.setText("This is the description provided." + id);
//(id);
// item item1 = {"Red rose", "@/drawable/", 1, 1.25};
// items.add(item1);
// now i will search for the array that holds the given id. and i will retrieve its info and display it again
// in the new layout.
}
}
您必须按照以下方式取值,
int id=0;
int position=0;
i=getIntent().getIntExtra("id",id);
position= getIntent().getIntExtra("position", position);
Toast.makeText( this, "id= " +id + " . and posistion= "+ position, Toast.LENGTH_LONG).show();
您误解了应该使用 Intent 的方式。 正确的形式是这样的:
int id =getIntent().getIntExtra("id",0);
int position = getIntent().getIntExtra("position", 0);
当你使用getIntExtra
时,第二个参数是默认值。如果您的意图中该标签没有这样的值,它将 return 该默认值。
有关详细信息,请参阅 Google docs