android - 为什么 `setPositiveButton` 总是返回 -1 以及如何获取选定的索引？

Question

我有一个对话框来显示在启动时切换应用程序自动启动的设置。

用户点击Enable或Disable，然后点击OK保存。

代码:

public void showShareDialog(final int itId, String title) {
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle(title);

    String positiveText = getString(android.R.string.ok);
    String negativeText = getString(android.R.string.cancel);
    String[] items;
    int default_i = 0;
    final SharedPreferences sharedPref = getSharedPreferences("quickSettings", MODE_PRIVATE);
    if (itId == AUTOSTART_LI) {
        items = getResources().getStringArray(R.array.toggle);
        final boolean autostart = sharedPref.getBoolean("autostart", false);
        Log.d("hole", "#autostart get:" + autostart);
        if (!autostart) default_i = 1;

    } else return;

    builder.setSingleChoiceItems(items, default_i, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    Log.d("hole", "single clicked" + which);

                }
            })
            .setPositiveButton(positiveText, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    Log.d("hole", "positive clicked:" + which);

                    if (itId == AUTOSTART_LI) {

                        int flag;
                        boolean autostart;
                        if (which == 0) {
                            flag = PackageManager.COMPONENT_ENABLED_STATE_ENABLED;
                            autostart = true;
                        } else {
                            flag = PackageManager.COMPONENT_ENABLED_STATE_DISABLED;
                            autostart = false;
                        }
                        ComponentName component = new ComponentName("com.blogspot.diannaoxiaobai.skyshot"
                                , "com.blogspot.diannaoxiaobai.skyshot.MyReceiver");
                        getPackageManager().setComponentEnabledSetting(component, flag, PackageManager.DONT_KILL_APP);

                        //save only if above no crash
                        SharedPreferences.Editor editor = sharedPref.edit();
                        Log.d("hole", "#autostart saved:" + autostart);
                        editor.putBoolean("autostart", autostart);
                        editor.commit();

                    }
                }
            })
            .setNegativeButton(negativeText, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    Log.d("hole", "negative clicked:" + which);
                }
            });

    AlertDialog dialog = builder.create();
    dialog.show();
}

但只有 setSingleChoiceItems 能够获取索引，而 setPositiveButton 的 which 变量总是打印 -1， logcat 例如:

05-12 03:14:41.983  5014  5014 D hole    : single clicked0
05-12 03:14:43.066  5014  5014 D hole    : single clicked1
05-12 03:14:43.615  5014  5014 D hole    : positive clicked:-1

Answer 1

将单选按钮的点击位置保存在 Int 变量中。

然后在您的 setPositiveButton 中单击检查字符串数组的值。

int index;   //declare Globally

builder.setSingleChoiceItems(items, default_i ,
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int item)                   {
                            index = item;   //save radio button click position
                    }
                });
builder.setPositiveButton(positiveText,
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int item) {
                        if (items[index] == "Enable") {
                            Toast.makeText(YourActivity.this, "Enable clicked.",Toast.LENGTH_SHORT).show();
                        }
                        if (items[index] == "Disable") {
                            Toast.makeText(YourActivity.this, "Disable clicked.",Toast.LENGTH_SHORT).show();
                        }
                    }
                });