为什么我不能点击在Android中使用SimpleAdapter一个ListView一个按钮? [英] Why can't I click a Button in a ListView using SimpleAdapter in android?

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问题描述

我是新手到Android。我已经发布了这个问题也较早,但没有找到合适的答案。我的要求是做一个按钮点击在列表视图这是使用生成一个 SimpleAdapter < /$c$c>.I不想使用 CustomAdapter BaseAdapter 或其它任何适配器。我不希望我的Activty延长为 SimpleAdapter 。我的code和错误日志如下:如果任何人有任何解决方案,请向我解释一步一步。谢谢你。

MainActivity.java

 公共类MainActivity延伸活动{@覆盖
保护无效的onCreate(捆绑savedInstanceState){
    super.onCreate(savedInstanceState);
    的setContentView(R.layout.activity_main);
    ArrayList的&LT;&HashMap的LT;字符串,字符串&GT;&GT; VAL1 =新的ArrayList&LT;&HashMap的LT;字符串,字符串&GT;&GT;();
    HashMap的&LT;字符串,字符串&GT; VAL =新的HashMap&LT;字符串,字符串&GT;();
    val.put(一,一个);
    val.put(C,C);
    val.put(B,B);
    val1.add(VAL);     最终的ListView L =(ListView控件)findViewById(R.id.listView1);
     ListAdapter K =新SimpleAdapter(这一点,VAL1,R.layout.mytask,新的String [] {任务id,标题,状态},新的INT [] {R.id.View1,R.id.View2 ,R.id.ViewStatus});     按钮B =(按钮)findViewById(R.id.mytask);
     b.setOnClickListener(新OnClickListener(){        @覆盖
        公共无效的onClick(查看为arg0){
            // TODO自动生成方法存根
            Toast.makeText(MainActivity.this,拯救,Toast.LENGTH_SHORT).show();
        }
    });
        l.setAdapter(K);
}

错误日志:

  1月4日至7日:43:07.075:E / AndroidRuntime(2113):致命异常:主要
  一月四日至七日:43:07.075:E / AndroidRuntime(2113):工艺:com.example.s,PID:2113
  一月四日至七日:43:07.075:E / AndroidRuntime(2113):了java.lang.RuntimeException:无法启动活动ComponentInfo {com.example.s / com.example.s.MainActivity}:显示java.lang.NullPointerException
  一月四日至七日:43:07.075:E / AndroidRuntime(2113):在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
  一月四日至七日:43:07.075:E / AndroidRuntime(2113):在android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
  一月四日至七日:43:07.075:E / AndroidRuntime(2113):在android.app.ActivityThread.access $ 800(ActivityThread.java:135)
  一月四日至七日:43:07.075:E / AndroidRuntime(2113):在android.app.ActivityThread $ H.handleMessage(ActivityThread.java:1196)
  一月四日至七日:43:07.075:E / AndroidRuntime(2113):在android.os.Handler.dispatchMessage(Handler.java:102)
  一月四日至七日:43:07.075:E / AndroidRuntime(2113):在android.os.Looper.loop(Looper.java:136)
  一月四日至七日:43:07.075:E / AndroidRuntime(2113):在android.app.ActivityThread.main(ActivityThread.java:5017)
  一月四日至七日:43:07.075:E / AndroidRuntime(2113):在java.lang.reflect.Method.invokeNative(本机方法)
  一月四日至七日:43:07.075:E / AndroidRuntime(2113):在java.lang.reflect.Method.invoke(Method.java:515)
  一月四日至七日:43:07.075:E / AndroidRuntime(2113):在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run(ZygoteInit.java:779)
  一月四日至七日:43:07.075:E / AndroidRuntime(2113):在com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
  一月四日至七日:43:07.075:E / AndroidRuntime(2113):在dalvik.system.NativeStart.main(本机方法)
 一月四日至七日:43:07.075:E / AndroidRuntime(2113):因:显示java.lang.NullPointerException
 一月四日至七日:43:07.075:E / AndroidRuntime(2113):在com.example.s.MainActivity.onCreate(MainActivity.java:34)
 一月四日至七日:43:07.075:E / AndroidRuntime(2113):在android.app.Activity.performCreate(Activity.java:5231)
 一月四日至七日:43:07.075:E / AndroidRuntime(2113):在android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
 一月四日至七日:43:07.075:E / AndroidRuntime(2113):在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
 一月四日至七日:43:07.075:E / AndroidRuntime(2113):11 ...更多

mytask.xml

 &LT;?XML版本=1.0编码=UTF-8&GT?;
&LT;的RelativeLayout的xmlns:机器人=htt​​p://schemas.android.com/apk/res/android
   机器人:layout_width =match_parent
   机器人:layout_height =match_parent
   机器人:方向=垂直&GT;&LT;的TextView
    机器人:ID =@ + ID / textView1
    机器人:layout_width =WRAP_CONTENT
    机器人:layout_height =WRAP_CONTENT
    机器人:layout_alignParentLeft =真
    机器人:layout_alignParentTop =真
    机器人:layout_marginTop =18dp
    机器人:文字=任务名称:    机器人:TEXTSIZE =15dp
    机器人:文字样式=大胆/&GT;&LT;的TextView
    机器人:ID =@ + ID /视图1
    机器人:layout_width =WRAP_CONTENT
    机器人:layout_height =WRAP_CONTENT
    机器人:layout_alignParentLeft =真
    机器人:layout_alignParentTop =真
    机器人:文字=TextView的    机器人:TEXTSIZE =15dp
    机器人:文字样式=大胆
    机器人:知名度=隐形/&GT;&LT;的TextView
    机器人:ID =@ + ID /视图2
    机器人:layout_width =WRAP_CONTENT
    机器人:layout_height =WRAP_CONTENT
    机器人:layout_alignBaseline =@ + ID / textView1
    机器人:layout_alignBottom =@ + ID / textView1
    机器人:layout_marginLeft =31dp
    机器人:layout_toRightOf =@ + ID / textView1
    机器人:文字=TextView的    机器人:TEXTSIZE =15dp
    机器人:文字样式=大胆
    机器人:知名度=看得见/&GT;&LT;的TextView
    机器人:ID =@ + ID / ViewStatus
    机器人:layout_width =WRAP_CONTENT
    机器人:layout_height =WRAP_CONTENT
    机器人:layout_alignBaseline =@ + ID /视图2
    机器人:layout_alignBottom =@ + ID /视图2
    机器人:layout_alignParentRight =真
    机器人:文字=待定    机器人:TEXTSIZE =15dp
    机器人:文字样式=大胆/&GT;&LT;的TextView
    机器人:ID =@ + ID / textView2
    机器人:layout_width =WRAP_CONTENT
    机器人:layout_height =WRAP_CONTENT
    机器人:layout_alignBaseline =@ + ID / ViewStatus
    机器人:layout_alignBottom =@ + ID / ViewStatus
    机器人:layout_marginRight =14dp
    机器人:layout_toLeftOf =@ + ID / ViewStatus
    机器人:文字=状态:    机器人:TEXTSIZE =15dp
    机器人:文字样式=大胆/&GT;&LT;按钮
    机器人:ID =@ + ID / mytask
    机器人:layout_width =WRAP_CONTENT
    机器人:layout_height =WRAP_CONTENT
    机器人:layout_alignParentLeft =真
    机器人:layout_below =@ + ID / textView1
    机器人:文字=按钮/&GT; &LT; / RelativeLayout的&GT;

activity_main.xml中

 &LT; ListView控件
    机器人:ID =@ + ID / ListView1的
    机器人:layout_width =match_parent
    机器人:layout_height =WRAP_CONTENT
    机器人:layout_alignParentLeft =真
    机器人:layout_alignParentTop =真
    机器人:layout_marginLeft =106dp
    机器人:layout_marginTop =124dp&GT;
&LT; /&的ListView GT;


解决方案

activity_main.xml中没有按钮 ID为 mytask 。所以你不能在MainActivtiy初始化按钮。

按钮属于 mytask.xml 覆盖getView并有按钮听者那里。

http://developer.android.com/reference/android/widget/ SimpleAdapter.html

编辑:

  SimpleAdapter K =新SimpleAdapter(这一点,VAL1,R.layout.mytask,新的String [] {A,C,B},新的INT [] {R.id.View1,R.id.View2,R.id.ViewStatus})
    {
        @覆盖
        公共查看getView(INT位置,查看convertView,父母的ViewGroup)
        {
            视图V = super.getView(位置,convertView,父母);             按钮B =(按钮)v.findViewById(R.id.mytask);
             b.setOnClickListener(新OnClickListener(){                @覆盖
                公共无效的onClick(查看为arg0){
                    // TODO自动生成方法存根
                    Toast.makeText(MainActivity.this,拯救,Toast.LENGTH_SHORT).show();
                }
            });
            返回伏;
        }
    };

编辑:既然你不相信这里的单元

I am a newbie to Android. I have posted this question earlier too but didn't find the appropriate answer. My requirement is to make a Button clickable in a Listviewwhich is generated using a SimpleAdapter.I don't want to use CustomAdapter,BaseAdapter or any other Adapter. I don't want to extend my Activty as SimpleAdapter.My code and error logs are as follows. If anyone has any solutions please explain to me step by step. Thank you.

MainActivity.java

 public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ArrayList<HashMap<String, String>>val1=new ArrayList<HashMap<String,String>>(); 
    HashMap<String, String>val=new HashMap<String,String>();
    val.put("a","a");
    val.put("c","c");
    val.put("b","b");
    val1.add(val);

     final ListView l=(ListView)findViewById(R.id.listView1);
     ListAdapter k=new SimpleAdapter(this,val1,R.layout.mytask,new String[]{"TaskId","heading","status"},new int[]{R.id.View1,R.id.View2,R.id.ViewStatus});

     Button b=(Button)findViewById(R.id.mytask);
     b.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub
            Toast.makeText(MainActivity.this,"save",Toast.LENGTH_SHORT).show();
        }
    });
        l.setAdapter(k);




}

Error log:

  04-07 01:43:07.075: E/AndroidRuntime(2113): FATAL EXCEPTION: main
  04-07 01:43:07.075: E/AndroidRuntime(2113): Process: com.example.s, PID: 2113
  04-07 01:43:07.075: E/AndroidRuntime(2113): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.s/com.example.s.MainActivity}: java.lang.NullPointerException
  04-07 01:43:07.075: E/AndroidRuntime(2113):   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
  04-07 01:43:07.075: E/AndroidRuntime(2113):   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
  04-07 01:43:07.075: E/AndroidRuntime(2113):   at android.app.ActivityThread.access$800(ActivityThread.java:135)
  04-07 01:43:07.075: E/AndroidRuntime(2113):   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
  04-07 01:43:07.075: E/AndroidRuntime(2113):   at android.os.Handler.dispatchMessage(Handler.java:102)
  04-07 01:43:07.075: E/AndroidRuntime(2113):   at android.os.Looper.loop(Looper.java:136)
  04-07 01:43:07.075: E/AndroidRuntime(2113):   at android.app.ActivityThread.main(ActivityThread.java:5017)
  04-07 01:43:07.075: E/AndroidRuntime(2113):   at java.lang.reflect.Method.invokeNative(Native Method)
  04-07 01:43:07.075: E/AndroidRuntime(2113):   at java.lang.reflect.Method.invoke(Method.java:515)
  04-07 01:43:07.075: E/AndroidRuntime(2113):   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
  04-07 01:43:07.075: E/AndroidRuntime(2113):   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
  04-07 01:43:07.075: E/AndroidRuntime(2113):   at dalvik.system.NativeStart.main(Native Method)
 04-07 01:43:07.075: E/AndroidRuntime(2113): Caused by: java.lang.NullPointerException
 04-07 01:43:07.075: E/AndroidRuntime(2113):    at com.example.s.MainActivity.onCreate(MainActivity.java:34)
 04-07 01:43:07.075: E/AndroidRuntime(2113):    at android.app.Activity.performCreate(Activity.java:5231)
 04-07 01:43:07.075: E/AndroidRuntime(2113):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
 04-07 01:43:07.075: E/AndroidRuntime(2113):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
 04-07 01:43:07.075: E/AndroidRuntime(2113):    ... 11 more

mytask.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:orientation="vertical" 

>

<TextView
    android:id="@+id/textView1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true"
    android:layout_marginTop="18dp"
    android:text="Task Name:"

    android:textSize="15dp"
    android:textStyle="bold" />

<TextView
    android:id="@+id/View1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true"
    android:text="TextView"

    android:textSize="15dp"
    android:textStyle="bold"
    android:visibility="invisible" />

<TextView
    android:id="@+id/View2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/textView1"
    android:layout_alignBottom="@+id/textView1"
    android:layout_marginLeft="31dp"
    android:layout_toRightOf="@+id/textView1"
    android:text="TextView"

    android:textSize="15dp"
    android:textStyle="bold"
    android:visibility="visible" />

<TextView
    android:id="@+id/ViewStatus"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/View2"
    android:layout_alignBottom="@+id/View2"
    android:layout_alignParentRight="true"
    android:text="Pending"

    android:textSize="15dp"
    android:textStyle="bold" />

<TextView
    android:id="@+id/textView2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/ViewStatus"
    android:layout_alignBottom="@+id/ViewStatus"
    android:layout_marginRight="14dp"
    android:layout_toLeftOf="@+id/ViewStatus"
    android:text="Status:"

    android:textSize="15dp"
    android:textStyle="bold" />

<Button
    android:id="@+id/mytask"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_below="@+id/textView1"
    android:text="Button" />

 </RelativeLayout>

activity_main.xml

 <ListView
    android:id="@+id/listView1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true"
    android:layout_marginLeft="106dp"
    android:layout_marginTop="124dp" >
</ListView>

解决方案

activity_main.xml does not have Button with id mytask. So you cannot initialize Button in MainActivtiy.

The Button belongs to mytask.xml override getView and have the button listener there.

http://developer.android.com/reference/android/widget/SimpleAdapter.html

Edit:

   SimpleAdapter k=new SimpleAdapter(this,val1,R.layout.mytask,new String[]{"a","c","b"},new int[]{R.id.View1,R.id.View2,R.id.ViewStatus})
    {
        @Override
        public View getView (int position, View convertView, ViewGroup parent)
        {
            View v = super.getView(position, convertView, parent);

             Button b=(Button)v.findViewById(R.id.mytask);
             b.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View arg0) {
                    // TODO Auto-generated method stub
                    Toast.makeText(MainActivity.this,"save",Toast.LENGTH_SHORT).show();
                }
            });
            return v;
        }


    };

Edit: Since you are not convinced here's the snap

这篇关于为什么我不能点击在Android中使用SimpleAdapter一个ListView一个按钮?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!

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