Question

我为我的微调器设置了一个自定义微调器适配器。这是我的适配器类：

public class MySpinnerAdapter extends ArrayAdapter<String> {
// Initialise custom font, for example:
Typeface font = Typeface.createFromAsset(getContext().getAssets(), "IRAN Sans Bold.ttf");
public MySpinnerAdapter(Context context, int resource, String[] items) {
    super(context, resource, items);
}

// Affects default (closed) state of the spinner
@Override
public View getView(int position, View convertView, ViewGroup parent) {
    TextView view = (TextView) super.getView(position, convertView, parent);
    view.setTypeface(font);
    return view;
}

// Affects opened state of the spinner
@Override
public View getDropDownView(int position, View convertView, ViewGroup parent) {
    TextView view = (TextView) super.getDropDownView(position, convertView, parent);
    view.setTypeface(font);
    return view;
}

}

这是simple_spinner布局：

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:gravity="right"
    android:textColor="#000"
    android:textSize="16dip" />

问题是，它使得微调器和我可以在微调器中看到第一个数组项，但是当我想打开下拉微调器时，它返回一个空错误：

FATAL EXCEPTION: main
                                                                             java.lang.NullPointerException
                                                                                 at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:394)
                                                                                 at android.widget.ArrayAdapter.getDropDownView(ArrayAdapter.java:415)
                                                                                 at ir.babaarzooni.persiandesigners.MySpinnerAdapter.getDropDownView(MySpinnerAdapter.java:33)
                                                                                 at android.support.v7.widget.AppCompatSpinner$DropDownAdapter.getDropDownView(AppCompatSpinner.java:637)
                                                                                 at android.support.v7.widget.AppCompatSpinner$DropDownAdapter.getView(AppCompatSpinner.java:633)
                                                                                 at android.support.v7.widget.AppCompatSpinner.compatMeasureContentWidth(AppCompatSpinner.java:560)
                                                                                 at android.support.v7.widget.AppCompatSpinner.access$500(AppCompatSpinner.java:64)
                                                                                 at android.support.v7.widget.AppCompatSpinner$DropdownPopup.computeContentWidth(AppCompatSpinner.java:751)
                                                                                 at android.support.v7.widget.AppCompatSpinner$DropdownPopup.show(AppCompatSpinner.java:776)
                                                                                 at android.support.v7.widget.AppCompatSpinner.performClick(AppCompatSpinner.java:434)
                                                                                 at android.view.View$PerformClick.run(View.java:17721)
                                                                                 at android.os.Handler.handleCallback(Handler.java:730)
                                                                                 at android.os.Handler.dispatchMessage(Handler.java:92)
                                                                                 at android.os.Looper.loop(Looper.java:137)
                                                                                 at android.app.ActivityThread.main(ActivityThread.java:5103)
                                                                                 at java.lang.reflect.Method.invokeNative(Native Method)
                                                                                 at java.lang.reflect.Method.invoke(Method.java:525)
                                                                                 at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
                                                                                 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
                                                                                 at dalvik.system.NativeStart.main(Native Method)

这是我的阵列：

 <array name="NearAxL">
    <item>انتخاب AX</item>
    <item>0</item>
    <item>0.25</item>
    <item>0.5</item>
    <item>0.75</item>
    <item>1</item>
    <item>1.25</item>
    <item>1.5</item>
    <item>1.75</item>
    <item>2</item>
    <item>2.25</item>
    <item>2.5</item>
    <item>2.75</item>
    <item>3</item>
</array>

这是java代码：

     NearAxR.setAdapter(new MySpinnerAdapter  (this,R.layout.simple_spinner,
            getResources().getStringArray(R.array.NearAxL)));

这段代码有什么问题？

Answer 1

此：

<array name="NearAxL">
    <item>انتخاب AX</item>
    <item>0</item>
    <item>0.25</item>
    <item>0.5</item>
    <item>0.75</item>
    <item>1</item>
    <item>1.25</item>
    <item>1.5</item>
    <item>1.75</item>
    <item>2</item>
    <item>2.25</item>
    <item>2.5</item>
    <item>2.75</item>
    <item>3</item>
</array>

应该是：

<string-array name="NearAxL">
    <item>انتخاب AX</item>
    <item>0</item>
    <item>0.25</item>
    <item>0.5</item>
    <item>0.75</item>
    <item>1</item>
    <item>1.25</item>
    <item>1.5</item>
    <item>1.75</item>
    <item>2</item>
    <item>2.25</item>
    <item>2.5</item>
    <item>2.75</item>
    <item>3</item>
</string-array>

array元素适用于Typed Arrays。字符串数组必须使用string-array。

如果仍然无效，请尝试使用内置微调器布局，如下所示

NearAxR.setAdapter(new MySpinnerAdapter  (this,android.R.layout.simple_spinner_item,
        getResources().getStringArray(R.array.NearAxL)));

android-自定义微调器数组适配器getDropDownView返回null

1 个答案: