Question

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Spinner并更改其值/内容。否则，用户不能通过单击“下一步”按钮进入下一个屏幕。

如何在Android中执行此操作？有人有任何想法吗？

先谢谢。

罗汉

Answer 1

你可以用这个：

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

这意味着用户没有选择任何内容。

Answer 2

让Spinner的第一个值类似于“-please select-”。

当用户点击下一个按钮执行验证并检查微调器中selectedItem的值是否为“-please select-”，如果是，则显示一个toast并要求用户从微调器中选择一些内容。

你需要代码，请告诉我。

Answer 3

致电Intent，了解该微调器的Activity中的下一个Click Listener

Answer 4

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，请将其设为isSelect = false。当用户点击“下一步”按钮时，isSelect的检查条件为真或假。

就是这样。

Answer 5

您可以使用以下方法获取所选项目值。

         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) {

            }
        });

Answer 6

在我的情况下，我在列表的第一个位置添加了一个额外的项目

1。＆＃34;选择一些东西＆＃34; 2。＆＃34;去下一个＆＃34; 3。＆＃34; Go Previous＆＃34; 5 .... 6 ..

然后使用

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
}

Answer 7

使用此代码进行检查 微调器 选择。

两个标志都在班级（全球）。

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 } } }

Answer 8

我制作了一个新的Spinner类来封装上面提到的原则。但即便如此，你必须确保调用正确的方法而不是setSelection

gist

中的相同内容

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);
    }
}

如何查找用户是否在Android中点击了微调器？

8 个答案: