Question

我的Android应用程序出现问题。这可能是一个简单的Java问题，但我不太清楚Java知道google的内容。下面是我所拥有的简化版本，说明了我的问题。我希望能够从对话框中访问gridview。显然我在这里所做的不对。我尝试在onCreate方法之外移动声明，但随后我的应用程序在开始时崩溃（没有错误消息）。我也尝试将它作为参数添加到ShowDialog，但我想因为我重写那个不起作用的函数。你可能会说，我不知道我在做什么。想法？

public class HelloGridView extends Activity {
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        final GridView gridview = (GridView) findViewById(R.id.gridview);
        gridview.setAdapter(new ImageAdapter(this));
        ((ImageAdapter) gridview.getAdapter()).initializemThumbIds();

        gridview.setOnItemClickListener(new OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
                showDialog(0);
            }
        });
    }

    protected Dialog onCreateDialog(int id) {
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setMessage("?")
               .setCancelable(false)
               .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                   public void onClick(DialogInterface dialog, int id) {
                       gridview.setAdapter(new ImageAdapter(this));  // gridview cannot be resolved
                       dialog.cancel();
                   }
               })
               .setNegativeButton("No", new DialogInterface.OnClickListener() {
                   public void onClick(DialogInterface dialog, int id) {
                       HelloGridView.this.finish();
                   }
               });
        AlertDialog diag = builder.create();
        return diag;
    }
}

Answer 1

我认为你没有正确的范围，所以下面我将gridView作为成员变量。但我认为你真正想做的是让你的ImageAdapter成为一个成员变量，只在你的对话框中更新ImageAdapter＆＃34;是＆＃34;点击。

public class HelloGridView extends Activity {
private GridView gridview;
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    gridview = (GridView) findViewById(R.id.gridview);
    gridview.setAdapter(new ImageAdapter(this));
    ((ImageAdapter) gridview.getAdapter()).initializemThumbIds();

    gridview.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
            showDialog(0);
        }
    });
}

protected Dialog onCreateDialog(int id) {
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setMessage("?")
           .setCancelable(false)
           .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
               public void onClick(DialogInterface dialog, int id) {
                   gridview.setAdapter(new ImageAdapter(this));  // gridview cannot be resolved
                   dialog.cancel();
               }
           })
           .setNegativeButton("No", new DialogInterface.OnClickListener() {
               public void onClick(DialogInterface dialog, int id) {
                   HelloGridView.this.finish();
               }
           });
    AlertDialog diag = builder.create();
    return diag;
}
}

如何从Dialog（Android）访问我的GridView实例？

1 个答案: