Question

此代码成功运行为从左到右的菜单滑块，我想在菜单中执行ListView的onclick，我尝试了各种方法，但没有成功。我调试代码但控件无法进入onClick。

public class MainActivity extends ListActivity {
ListView teams;
ArrayList<String> arr = new ArrayList<String>();
TextView tv0,tv1;
FlyOutContainer root;  ///////class for slider
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    tv0 = (Button)findViewById(R.id.tv0);
    tv1 = (Button)findViewById(R.id.tv1);
    this.root = 
             (FlyOutContainer)this.getLayoutInflater().inflate(R.layout.activity_main, null);

    this.setContentView(root);
    teams=getListView();
    arr.add("Introduction");
    arr.add("Preface");
    arr.add("Preamble");
    arr.add("Contents");
    arr.add("Articles");
    arr.add("Schedules");
    arr.add("Appendix");
    arr.add("Amendment");

ArrayAdapter<String> adptr = new  
                     ArrayAdapter<String>this,android.R.layout.simple_list_item_1,arr);
    setListAdapter(adptr);

//      
//      arr.setOnItemClickListener(new OnItemClickListener() { 
//          public void onItemClick(AdapterView<?> parent, View view,
//                  int position, long id) {
// 
//         Toast.makeText(getBaseContext(),getTitle(),Toast.LENGTH_SHORT).show();
//          }
//      });


/*
    teams.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
        int id = teams.getId();
        if(id==0)
    {
            tv0.setText("Introduction");
            tv1.setText("India ie. Bharat is a Union of States.");
        }

        if(id==1)
        {
            tv0.setText("Preface");
        }

        if(id==2)
        {
            tv0.setText("Preamble");
        }


        }
    });
 */
    teams.setOnItemClickListener(new AdapterView.OnItemClickListener()
    {

        @Override
        public void onItemClick(AdapterView<?> arg0, View arg1, int position,
                long arg3) {

            if(position==1)
            {

             tv0.setText("Introduction");
             tv1.setText("India ie. Bharat is a Union of States.");
                   toggleMenu(arg1);
              }
         }

     });
 }

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

public void toggleMenu(View v){
    this.root.toggleMenu();
}

  }

我尝试了很多但却犯了很多错误！

任何人都可以给我一个具体的答案感谢...

logcat的：

12-03 13:00:37.031: E/AndroidRuntime(2690): FATAL EXCEPTION: main
12-03 13:00:37.031: E/AndroidRuntime(2690): java.lang.NullPointerException
12-03 13:00:37.031: E/AndroidRuntime(2690):     at com.example.indianconstitution.MainActivity$1.onItemClick(MainActivity.java:88)
12-03 13:00:37.031: E/AndroidRuntime(2690):     at android.widget.AdapterView.performItemClick(AdapterView.java:298)
12-03 13:00:37.031: E/AndroidRuntime(2690):     at android.widget.AbsListView.performItemClick(AbsListView.java:1100)
12-03 13:00:37.031: E/AndroidRuntime(2690):     at android.widget.AbsListView$PerformClick.run(AbsListView.java:2788)
12-03 13:00:37.031: E/AndroidRuntime(2690):     at android.widget.AbsListView$1.run(AbsListView.java:3463)
12-03 13:00:37.031: E/AndroidRuntime(2690):     at android.os.Handler.handleCallback(Handler.java:730)
12-03 13:00:37.031: E/AndroidRuntime(2690):     at android.os.Handler.dispatchMessage(Handler.java:92)
12-03 13:00:37.031: E/AndroidRuntime(2690):     at android.os.Looper.loop(Looper.java:137)
12-03 13:00:37.031: E/AndroidRuntime(2690):     at android.app.ActivityThread.main(ActivityThread.java:5103)
12-03 13:00:37.031: E/AndroidRuntime(2690):     at java.lang.reflect.Method.invokeNative(Native Method)
12-03 13:00:37.031: E/AndroidRuntime(2690):     at java.lang.reflect.Method.invoke(Method.java:525)
12-03 13:00:37.031: E/AndroidRuntime(2690):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
12-03 13:00:37.031: E/AndroidRuntime(2690):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
12-03 13:00:37.031: E/AndroidRuntime(2690):     at dalvik.system.NativeStart.main(Native Method)

Answer 1

您尝试在设置内容视图之前检索tv0和tv1次观看。当您尝试访问它们时，tv0和tv1将为null。设置内容视图后移动findViewById(...)来电。前

   super.onCreate(savedInstanceState);
    this.root = (FlyOutContainer)this.getLayoutInflater().inflate(R.layout.activity_main, null);

    this.setContentView(root);
    tv0 = (Button)findViewById(R.id.tv0);
    tv1 = (Button)findViewById(R.id.tv1);

Answer 2

类似的东西应该有效：

private DrawerLayout mDrawerLayout;
private ListView mDrawerList;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    this.setContentView(root);
    tv0 = (Button)findViewById(R.id.tv0);
    tv1 = (Button)findViewById(R.id.tv1);
    mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
    mDrawerList = (ListView) findViewById(R.id.drawer_listview);
    this.root = 
             (FlyOutContainer)this.getLayoutInflater().inflate(R.layout.activity_main, null);


teams=getListView();
arr.add("Introduction");
arr.add("Preface");
arr.add("Preamble");
arr.add("Contents");
arr.add("Articles");
arr.add("Schedules");
arr.add("Appendix");
arr.add("Amendment");
ArrayAdapter<String> dataAdapter = new  
                 ArrayAdapter<String>(this,R.layout.simple_list_item_1,arr);
mDrawerListView.setAdapter(dataAdapter); //mDrawerListView is a ListView of your drawer
mDrawerListView.setOnItemClickListener(new DrawerItemClickListener());

这声明了DrawerItemClickListener。把它放在onCreate（）

之外

private class DrawerItemClickListener implements ListView.OnItemClickListener {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position,
                long id) {
            //do something according to position
            switch (position) {
            case 0: //do something
              break;

            case 1:
              break;

             }
        }
}

Answer 3

好的，我弄错了：

tv0＆amp; tv1声明为TextView但使用

tv0 = (Button)findViewById(R.id.tv0);

代替

tv0 = (TextView)findViewById(R.id.tv0);

＆安培;其余的代码绝对没问题

无法在滑块菜单中使用ListView的onClick（）

3 个答案: