5

在我的应用程序中，我在代码中动态创建微调器。我想强制用户单击微调器并更改其值/内容。否则，用户将无法通过单击“下一步”按钮进入下一个屏幕。

如何在 Android 中做到这一点？有人有什么想法吗？

提前致谢。

罗汉

4

8 回答 8

9

你可以使用这个：

 if (spin.getSelectedItemPosition() < 0) {//Do something}

这意味着用户没有选择任何东西。

于 2015-01-08T07:50:57.817 回答
2

让 Spinner 的第一个值类似于“-please select-”。

当用户单击下一个按钮时，执行验证并检查微调器中 selectedItem 的值是否为“-please select-”，如果是，则显示吐司并要求用户从微调器中选择一些东西。

你需要代码，让我知道。

于 2013-03-15T04:42:27.830 回答
1

使用此代码检查微调器项目是否被选中。

两个标志都在类级别（全局）。

Boolean temp = false;
Boolean check = false;


spinner1.setOnItemSelectedListener(new OnItemSelectedListener() {

        @Override
        public void onItemSelected(AdapterView<?> arg0, View arg1,
                int arg2, long arg3) {
            // TODO Auto-generated method stub
            if(temp){
                check = true;
            }
            temp = true;
        }

        @Override
        public void onNothingSelected(AdapterView<?> arg0) {
            // TODO Auto-generated method stub
            check = false;
        }
});

button.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub

            if(check){

                //perform when user select spinner item             
            }else{

                //put Dialog for alert please select spinner item 

            }
        }
}
于 2013-03-15T05:00:02.103 回答
0

创建一个布尔全局变量，如..

 boolean isSelect = false;

现在，当用户从微调器中选择值时，然后将其设为isSelect = false。当用户单击 NEXT 按钮时，检查条件isSelect是真还是假。

而已。

于 2013-03-15T04:27:10.470 回答
0

在那个微调器中调用你Intent的下一个ActivityClick Listener

于 2013-03-15T04:26:51.593 回答
0

您可以使用以下方法获取所选项目的值。

         spinner.setOnItemSelectedListener(new OnItemSelectedListener() {    
            public void onItemSelected(AdapterView<?> arg0, View arg1,
                    int arg2, long arg3) {
                if (spinner.getSelectedItem().toString().equals("YourValue")) {
                    Intent yourIntent = new Intent(this,YourClassName.class);
                    startActivity(yourIntent);
                }
            }    
            public void onNothingSelected(AdapterView<?> arg0) {

            }
        });
于 2013-03-15T04:43:49.360 回答
0

就我而言，我在列表的第一个位置添加了一个额外的项目

1.“选择一些东西” 2.“下一个” 3.“上一个” 5.... 6..

然后在使用

String item=spinnerObject.getSelectedItem ();
    now check if("Select Something".equels(item)){
show some dialog to select anything from spinner
    }else{
send it to next screen
}
于 2013-03-15T04:51:43.037 回答
0

我制作了一个新的 Spinner 类，封装了上述原则。但即使那样你也必须确保调用正确的方法而不是setSelection

要点相同

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.widget.AdapterView;

/**
 * Used this to differentiate between user selected and prorammatically selected
 * Call {@link Spinner#programmaticallySetPosition} to use this feature.
 * Created by vedant on 6/1/15.
 */
public class Spinner extends android.widget.Spinner implements AdapterView.OnItemSelectedListener {

    OnItemSelectedListener mListener;

    /**
     * used to ascertain whether the user selected an item on spinner (and not programmatically)
     */
    private boolean mUserActionOnSpinner = true;

    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {

        if (mListener != null) {

            mListener.onItemSelected(parent, view, position, id, mUserActionOnSpinner);
        }
        // reset variable, so that it will always be true unless tampered with
        mUserActionOnSpinner = true;
    }

    @Override
    public void onNothingSelected(AdapterView<?> parent) {
        if (mListener != null)
            mListener.onNothingSelected(parent);
    }

    public interface OnItemSelectedListener {
        /**
         * <p>Callback method to be invoked when an item in this view has been
         * selected. This callback is invoked only when the newly selected
         * position is different from the previously selected position or if
         * there was no selected item.</p>
         *
         * Impelmenters can call getItemAtPosition(position) if they need to access the
         * data associated with the selected item.
         *
         * @param parent The AdapterView where the selection happened
         * @param view The view within the AdapterView that was clicked
         * @param position The position of the view in the adapter
         * @param id The row id of the item that is selected
         */
        void onItemSelected(AdapterView<?> parent, View view, int position, long id, boolean userSelected);

        /**
         * Callback method to be invoked when the selection disappears from this
         * view. The selection can disappear for instance when touch is activated
         * or when the adapter becomes empty.
         *
         * @param parent The AdapterView that now contains no selected item.
         */
        void onNothingSelected(AdapterView<?> parent);
    }

    public void programmaticallySetPosition(int pos, boolean animate) {
        mUserActionOnSpinner = false;
        setSelection(pos, animate);
    }

    public void setOnItemSelectedListener (OnItemSelectedListener listener) {
        mListener = listener;
    }

    public Spinner(Context context) {
        super(context);
        super.setOnItemSelectedListener(this);
    }

    public Spinner(Context context, int mode) {
        super(context, mode);
        super.setOnItemSelectedListener(this);
    }

    public Spinner(Context context, AttributeSet attrs) {
        super(context, attrs);
        super.setOnItemSelectedListener(this);
    }

    public Spinner(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        super.setOnItemSelectedListener(this);
    }

    public Spinner(Context context, AttributeSet attrs, int defStyle, int mode) {
        super(context, attrs, defStyle, mode);
        super.setOnItemSelectedListener(this);
    }
}
于 2015-01-06T19:16:46.907 回答