[問題] AlertDialog裡加入有Checkbox的Listview

看板AndroidDev作者whow (somebody)時間12年前 (2013/08/20 05:05)推噓4(4推 0噓 7→)

留言11則, 3人參與討論串1/2 (看更多)

如標題我想在要我的MainActivity中按下一個按鈕跳出AlertDialog 讓使用者有一個List可以選擇自己想要的選項並且有checkbox可以複選等到按下確認鍵後再把這些選項存起來看起來應該是要自己寫一個Adapter 但是我試了好久老是在listview.setAdapter(adapter)出錯 //listview是我ListView物件 adapter是我自己寫的Adapter 因為我把這行註解起來後程式是可以執行的@@ 我的想法是： MyAdapter adapter = new MyAdapter(String[] items, MainActivity.this); 先宣告一個自己寫的adapter MyAdapter的Constructor： MyAdapter(String[] name, Context context){ /* 把給定的項目存到一個list裏 initialize checkbox的狀態 */ inflater = LayoutInflater.from(context); } 而getview則是這樣： public View getView(int position, View convertView, ViewGroup parent) { View view=null; ViewHolder holder = null; if (map.get(position) == null) { //map是一個用來存位置和view的HashMap view = inflater.inflate(R.layout.item, null); holder = new ViewHolder(); holder.selected = (CheckBox)view.findViewById(R.id.item_cb); holder.name = (TextView)view.findViewById(R.id.item_tv); final int p = position; map.put(position, view); holder.selected.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { CheckBox cb = (CheckBox)v; mChecked.set(p, cb.isChecked()); //mChecked為項目是否被選取的list } }); view.setTag(holder); }else{ view = map.get(position); holder = (ViewHolder)view.getTag(); } holder.selected.setChecked(mChecked.get(position)); holder.name.setText(list.get(position)); return view; } 在MainActivity中有這幾行： ListView lv = (ListView)findViewById(R.id.list); adapter = new MyAdapter(items, MainActivity.this); lv.setAdapter(adapter); new AlertDialog.Builder(Gps_test.this) .setTitle("CheckBoxtest") .setView(lv) .setPositiveButton(...){...} .setNegativeButton(...){...} .show(); 標記起來的地方是我覺得可能有錯的地方已經卡一兩天了煩請各位幫忙@@ 這段code是從網路上找到的有自己修改一點如果有哪裡描述不夠清楚我會再補上!! -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 218.164.149.193

推

shawnba

08/20 09:45, , 1^F

08/20 09:45, 1^F

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shawnba

08/20 09:46, , 2^F

08/20 09:46, 2^F

推

givemepass

08/20 12:00, , 3^F

08/20 12:00, 3^F

s大指的是ListView lv = (ListView)findViewById(R.id.list); 要改成ListView lv = (ListView)lv.findViewById(R.id.list); 嗎? 我試過了還是一樣@@ m大指的log是這個嗎? 08-20 13:25:52.868: D/AndroidRuntime(2061): Shutting down VM 08-20 13:25:52.868: W/dalvikvm(2061): threadid=1: thread exiting with uncaught exception (group=0x400259f8) 08-20 13:25:52.868: E/AndroidRuntime(2061): FATAL EXCEPTION: main 08-20 13:25:52.868: E/AndroidRuntime(2061): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.project/com.example.project.MainActivity}: java.lang.NullPointerException 08-20 13:25:52.868: E/AndroidRuntime(2061): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2787) 08-20 13:25:52.868: E/AndroidRuntime(2061): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2803) 08-20 13:25:52.868: E/AndroidRuntime(2061): at android.app.ActivityThread.access$2300(ActivityThread.java:135) 08-20 13:25:52.868: E/AndroidRuntime(2061): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2136) 08-20 13:25:52.868: E/AndroidRuntime(2061): at android.os.Handler.dispatchMessage(Handler.java:99) 08-20 13:25:52.868: E/AndroidRuntime(2061): at android.os.Looper.loop(Looper.java:144) 08-20 13:25:52.868: E/AndroidRuntime(2061): at android.app.ActivityThread.main(ActivityThread.java:4937) 08-20 13:25:52.868: E/AndroidRuntime(2061): at java.lang.reflect.Method.invokeNative(Native Method) 08-20 13:25:52.868: E/AndroidRuntime(2061): at java.lang.reflect.Method.invoke(Method.java:521) 08-20 13:25:52.868: E/AndroidRuntime(2061): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858) 08-20 13:25:52.868: E/AndroidRuntime(2061): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 08-20 13:25:52.868: E/AndroidRuntime(2061): at dalvik.system.NativeStart.main(Native Method) 08-20 13:25:52.868: E/AndroidRuntime(2061): Caused by: java.lang.NullPointerException 08-20 13:25:52.868: E/AndroidRuntime(2061): at com.example.project.MainActivity.showCheckBoxListView(MainActivity.java:253) 08-20 13:25:52.868: E/AndroidRuntime(2061): at com.example.project.MainActivity.onCreate(MainActivity.java:103) 08-20 13:25:52.868: E/AndroidRuntime(2061): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1069) 08-20 13:25:52.868: E/AndroidRuntime(2061): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2751) 08-20 13:25:52.868: E/AndroidRuntime(2061): ... 11 more 這是我用eclipse跑完後再logcat找到的 ※ 編輯: whow 來自: 218.164.149.193 (08/20 13:35)

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givemepass

08/20 13:39, , 4^F

08/20 13:39, 4^F

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givemepass

08/20 13:40, , 5^F

08/20 13:40, 5^F

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whow

08/20 13:51, , 6^F

08/20 13:51, 6^F