Question

我的项目有效，但ListView没有显示任何内容！我的代码出了什么问题？

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/background"
android:orientation="vertical"
android:padding="6dp">

<TextView
    android:id="@+id/textViewTitle"
    style="@style/styleText"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:gravity="center_horizontal"
    android:text="@string/titleAddition"
     />

<View
    android:layout_width="match_parent"
    android:layout_height="1dp"
    android:background="#EAF7C0" />
<ListView
    android:id="@+id/listViewExamples"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_weight="1"
    android:paddingTop="6dp"
    />
<View
    android:layout_width="match_parent"
    android:layout_height="1dp"
    android:background="#EAF7C0"
    />
<TextView
    android:id="@+id/textViewCalculate"
    style="@style/styleText"
    android:paddingTop="5dp"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:gravity="bottom|center"
    android:text="@string/Addition1"
    android:paddingBottom="5dp"
    />
<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_weight="0"
    android:gravity="center"
    android:orientation="horizontal">

    <EditText
        android:id="@+id/Num1"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:gravity="center"
        android:hint="@string/zero"
        android:inputType="number"
        android:textSize="24sp" />

    <TextView
        android:id="@+id/textViewSign"
        style="@style/styleText"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:gravity="center"
        android:text="@string/AdditionMark"
        android:textSize="28sp" />

    <EditText
        android:id="@+id/Num2"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:gravity="center"
        android:hint="@string/zero"
        android:inputType="number"
        android:textSize="24sp" />

    <TextView
        style="@style/styleText"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:gravity="center"
        android:text="@string/eqwal"
        android:textSize="28sp" />

    <TextView
        android:id="@+id/textViewTotal"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:gravity="center"
        android:hint="@string/zero"
        android:textSize="24sp" />

</LinearLayout>

<Button
    android:id="@+id/buttonResult"
    android:layout_width="match_parent"
    android:layout_height="30dp"
    android:layout_weight="0"
    android:background="#EAF7C0"
    android:onClick="result"
    android:text="@string/result"
    android:textAppearance="@android:style/TextAppearance" />

</LinearLayout>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="100dp"
android:background="@color/background"
android:orientation="horizontal">

<ImageView
    android:id="@+id/imageViewQuality"
    android:layout_width="120dp"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:scaleType="fitXY"
    app:srcCompat="@drawable/additionex1"
    />

<LinearLayout
    android:id="@+id/qualityColor"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal"
    >

    <TextView
        android:id="@+id/textViewQualty"
        style="@style/styleText2"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center|left"
        android:paddingLeft="3dp"
        android:text="@string/sum"
        />


</LinearLayout>

这些是课程。

public class Examples {

private String textQuality;
private int imageResource;

public Examples(String textQuality, int imageResource) {
    this.textQuality = textQuality;
    this.imageResource = imageResource;
}

public String getTextQuality() {
    return textQuality;
}

public int getImageResource() {
    return imageResource;
}

}

public class ExampleAdapter extends ArrayAdapter<Examples> {

private int mColorResourceId;

public ExampleAdapter(@NonNull Activity context, ArrayList<Examples> examples , int mColorResourceId) {
    super(context,0, mColorResourceId);

    this.mColorResourceId = mColorResourceId;
}

@NonNull
@Override
public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {

    View listItemView = convertView;
    if (listItemView == null) {
        listItemView = LayoutInflater.from(getContext()).inflate(R.layout.exampl_activity, parent, false);
    }
    Examples currentExample = getItem(position);

    TextView textView = (TextView) listItemView.findViewById(R.id.textViewQualty);
    textView.setText(currentExample.getTextQuality());

    ImageView imageView = (ImageView) listItemView.findViewById(R.id.imageViewQuality);
    imageView.setImageResource(currentExample.getImageResource());

    View textContainer = listItemView.findViewById(R.id.qualityColor);
    // Find the color that the resource ID maps to
    int color = ContextCompat.getColor(getContext(), mColorResourceId);
    // Set the background color of the text container View
    textContainer.setBackgroundColor(color);


    return listItemView;

}}


public class Addition extends AppCompatActivity {

TextView titleTextView;
TextView calculateText;
EditText num1;
EditText num2;
TextView textMark;
TextView total;
Button button;
ListView listView;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.list_item);

    titleTextView = (TextView) findViewById(R.id.textViewTitle);
    calculateText = (TextView) findViewById(R.id.textViewCalculate);
    textMark = (TextView) findViewById(R.id.textViewSign);
    button = (Button) findViewById(R.id.buttonResult);
    listView = (ListView) findViewById(R.id.listViewExamples);

    titleTextView.setText(getString(R.string.titleAddition));
    calculateText.setText(getString(R.string.Addition1));


    titleTextView.setText(R.string.titleAddition);
    calculateText.setText(R.string.Addition1);
    textMark.setText(R.string.AdditionMark);

    button.setOnClickListener(new View.OnClickListener() {
        @SuppressLint("SetTextI18n")
        @Override
        public void onClick(View v) {
            num1 = (EditText) findViewById(R.id.Num1);
            num2 = (EditText) findViewById(R.id.Num2);
            total = (TextView) findViewById(R.id.textViewTotal);

            int Num1 = Integer.parseInt(num1.getText().toString());
            int Num2 = Integer.parseInt(num2.getText().toString());
            int val = Num1 + Num2;

            total.setText(Integer.toString(val));
        }
    });


    final ArrayList<Examples> arrayList = new ArrayList<Examples>();

    arrayList.add(new Examples("5 + 0 = 5", R.drawable.additionex1));
    arrayList.add(new Examples("1 + 1 = 2", R.drawable.additionex2));
    arrayList.add(new Examples("3 + 3 = 6", R.drawable.additionex3));
    arrayList.add(new Examples("2 + 7 = 9", R.drawable.additionex4));
    arrayList.add(new Examples("5 + 3 = 8", R.drawable.additionex5));
    arrayList.add(new Examples("6 + 7 = 13", R.drawable.additionex6));
    arrayList.add(new Examples("9 + 2 = 11", R.drawable.additionex7));
    arrayList.add(new Examples("8 + 2 = 10", R.drawable.additionex8));

    ExampleAdapter adapter = new ExampleAdapter(this,arrayList,R.color.colorAddition);
    listView.setAdapter(adapter);


}

}

我没有在代码中看到任何错误，只是Logcat中的这条消息：

E / OpenGLRenderer：从GradienCache获取MAX_TEXTURE_SIZE MAX_TEXTURE_SIZE：16384 E / OpenGLRenderer：从Caches :: initConstraints（）获取MAX_TEXTURE_SIZE MAX_TEXTURE_SIZE：16384

请帮帮我，抱歉我不会说英语。

ListView没有显示任何内容？

0 个答案: