Question

单击按钮时，我需要将数据添加到gridview表。我的代码：

    String[] data = {"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k"};
    GridView gvMain;
    ArrayAdapter<String> adapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.smena); 
          adapter = new ArrayAdapter<String>(this, R.layout.item, R.id.tvText, data);
                gvMain = (GridView) findViewById(R.id.gridView1);
                gvMain.setAdapter(adapter);
           Button but1=(Button) findViewById(R.id.button1);
            but1.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View arg0) {

                     ButtonOn (1);
                }
            });
    }

    public void ButtonOn (int Art){
        adapter.add("1");
        gvMain.setAdapter(adapter);
    }

当我点击按钮时，我的应用程序意外停止。

Answer 1

ArrayAdapter将数组转换为无法修改的AbstractList（List）。在初始化ArrayAdapter时使用ArrayList而不是使用数组。

String[] data = { "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k" };

    ArrayList<String> lst = new ArrayList<String>();
    GridView gvMain;

    ArrayAdapter<String> adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.smena);

        lst.addAll(Arrays.asList(data));        
        adapter = new ArrayAdapter<String>(this, R.layout.title_bar, R.id.editText1,lst);

        gvMain = (GridView) findViewById(R.id.gridView1);
        gvMain.setAdapter(adapter);

        Button but1 = (Button) findViewById(R.id.button1);
        but1.setOnClickListener(new OnClickListener() {

            public void onClick(View arg0) {

                ButtonOn(1);
            }
        });
    }

    public void ButtonOn(int Art) {
        lst.add("1");       
        gvMain.setAdapter(adapter);
    }

Answer 2

Try This Code   

 String[] items = {"a","b","c","d","e","f"};



            Button b = (Button)findViewById(R.id.button1);

            b.setOnClickListener(new View.OnClickListener() {

                @Override
                public void onClick(View v) {
                    // TODO Auto-generated method stub
                    GridView gridView = (GridView)findViewById(R.id.gridView1);

                    gridView.setAdapter(new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_list_item_1, items));

(or)

gridView.setAdapter(new ArrayAdapter<String>(getApplicationContext(),R.layout.cust,  R.id.textView1, items));

                }
            });

Answer 3

LogCat显示什么样的错误......

如果它显示“空指针异常”或“无法启动活动”，那么您应该尝试对单个活动中的所有项进行膨胀，或者将数据正确地用于您的活动并在新活动中显示GridView。

希望你理解我的想法。更重要的是，不建议将活动用作活动的内容，因为它们会占用更多内存。我知道有许多教程遵循相同的原则，但隐藏了缺点。

如何为gridview增加价值

3 个答案: