Question

经历了许多演示，并且无法弄清楚如何在列表视图中使用imageview。尝试了代码但是在listview中看不到图像。其他详细信息在列表视图中正常工作请帮忙。

以下是代码主要活动有tabhost。在第二个选项卡下，列表视图存在。 listdata是我在列表中需要的数据。 MyBaseAdapter用于在listview中加载数据所需的适配器。

MainActivity.java

package com.example.trial;

import java.util.ArrayList;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.NumberPicker;
import android.widget.TabHost;
import android.widget.TabHost.TabSpec;
import android.widget.Toast;


public class MainActivity extends Activity {
    ListView list;
    String[] dish={"Baby Corn Satay","Dum Aloo","Kadai Paneer","Methi Mutter Malai","Paneer Butter Masala","Saag Panner","Veg Kolhapuri"};
    String[] about={"Baby Corn with marinade in a skewer","Baby Poatatoes in a spicy gravy","Kadhai paneer","Methi and peas in malai","Cottage cheese in butter masala","Cottage cheese in gravy","Spicy veg mix"};
    String[] dprice={"250","300","350","250","350","250","300"};
    Integer[] icon={R.drawable.baby_corn_satay,R.drawable.dum_aloo,R.drawable.kadai_paneer,R.drawable.methi_mutter_malai,R.drawable.paneer_butter_masaala,R.drawable.saag_paneer,R.drawable.veg_kolhapuri};
    ArrayList<ListData> myList=new ArrayList<ListData>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TabHost th=(TabHost) findViewById (R.id.tabhost);
        th.setup();
        TabSpec specs=th.newTabSpec("tag1");
        specs.setContent(R.id.tab1);
        specs.setIndicator("Beverages");
        th.addTab(specs);
         list=(ListView)findViewById(R.id.list);
            getInList();
                    list.setAdapter(new MyBaseAdapter(MainActivity.this,myList));
                    list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                        @Override
                        public void onItemClick(AdapterView<?> parent, View view,
                                                int position, long id) {
                            Toast.makeText(MainActivity.this, "You Clicked at " +dish[+ position], Toast.LENGTH_SHORT).show();
                        }
                    });
        specs=th.newTabSpec("tag2");
        specs.setContent(R.id.tab2);
        specs.setIndicator("Cuisines");
        th.addTab(specs);
        specs=th.newTabSpec("tag3");
        specs.setContent(R.id.tab3);
        specs.setIndicator("Desserts");
        th.addTab(specs);
        specs=th.newTabSpec("tag4");
        specs.setContent(R.id.tab4);
        specs.setIndicator("Tri");
        th.addTab(specs);






    }
    private void getInList(){

        for(int i=0;i<7;i++)
        {
        ListData ld=new ListData();
            ld.setAbout(about[i]);
            ld.setDish(dish[i]);
            ld.setDprice(dprice[i]);
            ld.seticon(icon[i]);
            myList.add(ld);
        }

        }


}

MainActivity.xml

<RelativeLayout 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"
    tools:context=".MainActivity" >

    <TabHost
        android:id="@+id/tabhost"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_alignParentTop="true" >

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical" >

            <TabWidget
                android:id="@android:id/tabs"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" >
            </TabWidget>

            <FrameLayout
                android:id="@android:id/tabcontent"
                android:layout_width="match_parent"
                android:layout_height="match_parent" >

                <RelativeLayout
                    android:id="@+id/tab1"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    tools:ignore="Orientation" >

                    <Button
                        android:id="@+id/button1"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_alignParentLeft="true"
                        android:layout_alignParentTop="true"
                        android:layout_marginLeft="529dp"
                        android:layout_marginTop="221dp"
                        android:text="Tab1"
                        tools:ignore="HardcodedText" />
                </RelativeLayout>

                <RelativeLayout
                    android:id="@+id/tab2"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    tools:ignore="Orientation" >



                                        <ListView
                                            android:id="@+id/list"
                                            android:layout_width="match_parent"
                                            android:layout_height="wrap_content"
                                            tools:ignore="TooDeepLayout" >

                                        </ListView>

                </RelativeLayout>

                <RelativeLayout
                    android:id="@+id/tab3"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    tools:ignore="Orientation" >

                    <Button
                        android:id="@+id/button3"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_alignParentLeft="true"
                        android:layout_alignParentTop="true"
                        android:layout_marginLeft="529dp"
                        android:layout_marginTop="221dp"
                        android:text="Tab3"
                        tools:ignore="HardcodedText" />
                </RelativeLayout>
                <RelativeLayout
                    android:id="@+id/tab4"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    tools:ignore="Orientation" >
                      <Button
                        android:id="@+id/button44"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_alignParentLeft="true"
                        android:layout_alignParentTop="true"
                        android:layout_marginLeft="529dp"
                        android:layout_marginTop="221dp"
                        android:text="tab4"
                        tools:ignore="HardcodedText" />
                </RelativeLayout>
            </FrameLayout>
        </LinearLayout>
    </TabHost>

</RelativeLayout>

MyBaseAdapter.java

package com.example.trial;

import java.util.ArrayList;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.NumberPicker;
import android.widget.TextView;

public class MyBaseAdapter extends BaseAdapter {

    ArrayList<ListData> myList=new ArrayList<ListData>();
    LayoutInflater inflater;
    Context context;
    public MyBaseAdapter(Context context,ArrayList<ListData> myList){
    this.myList=myList;
    this.context=context;
    inflater=LayoutInflater.from(this.context);
}

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return myList.size();
    }

    @Override
    public ListData getItem(int position) {
        // TODO Auto-generated method stub
        return myList.get(position);
    }

    @Override
    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        MyViewHolder mvh;
        if(convertView==null)
        {
            convertView=inflater.inflate(R.layout.dishview,null);
            mvh=new MyViewHolder();
            convertView.setTag(mvh);
        }
        else
        {
            mvh=(MyViewHolder) convertView.getTag();

        }

        mvh.dish  = detail (convertView,R.id.dish,myList.get(position).getDish());
        mvh.dprice= detail (convertView,R.id.price,myList.get(position).getDprice());
        mvh.about  = detail (convertView,R.id.about,myList.get(position).getAbout());
        mvh.icon= idetail(convertView,R.id.icon,myList.get(position).geticon());
        NumberPicker np = (NumberPicker) convertView.findViewById(R.id.qty);
           np.setMaxValue(9);
           np.setMinValue(1);
           np.setValue(1);
          Button b = (Button) convertView.findViewById(R.id.b1);
          b.setTag(convertView);
        return convertView;
    }


    private  ImageView idetail(View v,int resId,int icon)
    {
        ImageView iv=(ImageView) v.findViewById(resId);
    iv.setImageResource(resId);
    return iv;

    }

    private  TextView detail(View v,int resId,String text)
    {
        TextView tv=(TextView)v.findViewById(resId);
        tv.setText(text);
        return tv;
    }

    private static class MyViewHolder{
        TextView about,dish,dprice;
        ImageView icon;
    }



}

ListData.java

package com.example.trial;
import android.widget.NumberPicker;
public class ListData {
    String dish;
    String about;
     String dprice;
     Integer icon;

    public String getDish() {
        return dish;
    }
    public void setDish(String dish) {
        this.dish = dish;
    }
    public String getAbout() {
        return about;
    }
    public void setAbout(String about) {
        this.about = about;
    }
    public String getDprice() {
        return dprice;
    }
    public void setDprice(String dprice) {
        this.dprice = dprice;
    }
    public Integer geticon() {
        return icon;
    }
    public void seticon(Integer imageId) {
        this.icon = imageId;
    }
}

dishview.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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" >

    <TextView
        android:id="@+id/about"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/icon"
        android:layout_alignLeft="@+id/dish"
        android:text="Discription"
        android:textAppearance="?android:attr/textAppearanceSmall"
        tools:ignore="HardcodedText" />

    <ImageView
        android:id="@+id/icon"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignTop="@+id/dish"
        android:layout_marginLeft="49dp"
        android:maxHeight="100dp"
        android:maxWidth="100dp"
        android:src="@drawable/ic_launcher"
        tools:ignore="ContentDescription" />

    <TextView
        android:id="@+id/dish"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="36dp"
        android:layout_marginTop="27dp"
        android:layout_toRightOf="@+id/icon"
        android:text="Dish name"
        android:textAppearance="?android:attr/textAppearanceMedium"
        tools:ignore="HardcodedText" />

    <TextView
        android:id="@+id/price"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/about"
        android:layout_marginRight="146dp"
        android:layout_toLeftOf="@+id/qty"
        android:text="Price"
        android:textAppearance="?android:attr/textAppearanceMedium"
        tools:ignore="HardcodedText" />

    <NumberPicker
        android:id="@+id/qty"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        tools:ignore="NewApi" />

    <Button
        android:id="@+id/b1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignTop="@+id/price"
        android:layout_marginLeft="41dp"
        android:layout_toRightOf="@+id/qty"
        android:text="Add"
        tools:ignore="HardcodedText" />

</RelativeLayout>

请帮助我。感谢您的期待。

Answer 1

刚改变布局位置并停止工作

清洁并重建。可能您的二进制XML文件中的资源ID和R.java不同步。

现在您已经包含了logcat，java.lang.ClassCastException: android.widget.ImageView cannot be cast to android.widget.TextView中的detail()也表明了这一点 - 您传递给该方法的资源ID有效TextView但至少在一种情况是指二进制XML中的ImageView。

Answer 2

你能粘贴你的activity_main.xml吗？此外，您最好使用操作栏标签。

Answer 3

错误在MyBaseAdapter.java中简单的错误，参数不匹配。

  private  ImageView idetail(View v,int resId,int icon)
    {
        ImageView iv=(ImageView) v.findViewById(resId);
    iv.setImageResource(resId);
    return iv;

    }

我们需要将其更改为

 private  ImageView idetail(View v,int resId,int icon)
    {
        ImageView iv=(ImageView) v.findViewById(R.id.icon);
    iv.setImageResource(icon);
    return iv;

    }

图像未显示在列表视图中

3 个答案: