java - 使用 TextWatcher 计算 EditTexts 之间的平均值

Question

我在 android studio 上的项目有问题，我需要你的帮助。我用 3 个 EditText 和一个 Textview 创建了一行。我想在 EditText 上写数字并在 Textview 上计算平均值。当我点击它时，我还使用一个按钮来创建一个新行。我在第一行实现了计算，但每次我尝试计算创建按钮的行时，我都没有得到结果。这是我的代码:

public class MainActivity extends AppCompatActivity {
private LinearLayout parentLinearLayout;
private BreakIterator resultsText;
EditText editText1;
EditText editText2;
EditText editText3;
TextView textViewResult;


@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    parentLinearLayout = (LinearLayout) findViewById(R.id.parent_linear_layout);
    editText1 = (EditText) findViewById(R.id.number_edit_text1);
    editText2 = (EditText) findViewById(R.id.number_edit_text2);
    editText3 = (EditText) findViewById(R.id.number_edit_text3);

    textViewResult = (TextView) findViewById(R.id.number_text_view);

    editText1.addTextChangedListener(new TextWatcher() {

        public void beforeTextChanged(CharSequence s, int start, int count,
                                      int after) {
            // TODO Auto-generated method stub
        }

        public void onTextChanged(CharSequence s, int start, int before,
                                  int count) {
            textViewResult.setText(avg());
        }

        public void afterTextChanged(Editable s) {
            // TODO Auto-generated method stub
        }
    });

    editText2.addTextChangedListener(new TextWatcher() {

        public void beforeTextChanged(CharSequence s, int start, int count,
                                      int after) {
            // TODO Auto-generated method stub

        }

        public void onTextChanged(CharSequence s, int start, int before,
                                  int count) {
            textViewResult.setText(avg());

        }

        public void afterTextChanged(Editable s) {
            // TODO Auto-generated method stub

        }
    });
    editText3.addTextChangedListener(new TextWatcher() {

        public void beforeTextChanged(CharSequence s, int start, int count,
                                      int after) {
            // TODO Auto-generated method stub

        }

        public void onTextChanged(CharSequence s, int start, int before,
                                  int count) {
            textViewResult.setText(avg());

        }

        public void afterTextChanged(Editable s) {
            // TODO Auto-generated method stub

        }
    });
}

private String avg() {
    int number1;
    int number2;
    int number3;
    if(editText1.getText().toString() != "" && editText1.getText().length() > 0) {
        number1 = Integer.parseInt(editText1.getText().toString());
    } else {
        number1 = 0;
    }
    if(editText2.getText().toString() != "" && editText2.getText().length() > 0) {
        number2 = Integer.parseInt(editText2.getText().toString());
    } else {
        number2 = 0;
    }
    if(editText3.getText().toString() != "" && editText3.getText().length() > 0) {
        number3 = Integer.parseInt(editText3.getText().toString());
    } else {
        number3 = 0;
    }

    return Integer.toString((number1 + number2 + number3)/3 );
}

public void onAddField(View v) {
    LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    final View rowView = inflater.inflate(R.layout.field, null);
    // Add the new row before the add field button.
    parentLinearLayout.addView(rowView, parentLinearLayout.getChildCount() - 1);


}

public void onDelete(View v) {
    parentLinearLayout.removeView((View) v.getParent());
}

}

还有两个 .xml 文件: activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/parent_linear_layout"
    android:layout_width="match_parent"
    android:layout_height="495dp"
    android:layout_margin="0dp"
    android:orientation="vertical"
    android:weightSum="1">

    <TableLayout
        android:id="@+id/tlTable01"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#CCC"
        android:orientation="vertical"
        android:paddingTop="0dp"
        android:theme="@style/AppTheme">

        <TableRow
            android:id="@+id/tableRow1"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="#7CFC00"
            android:gravity="center_horizontal"
            android:paddingBottom="1dp">

            <TextView
                android:id="@+id/textView"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:background="#7CFC00"
                android:gravity="left"
                android:padding="5dp"
                android:text="Scoring List"
                android:textSize="18dp"
                android:textStyle="bold"
                android:typeface="serif" />

            <EditText
                android:layout_width="190dp"
                android:layout_height="match_parent"
                android:layout_marginLeft="1dp"
                android:background="#FFF"
                android:digits="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZαβγδεζηθικλμνξοπρστυφχψωΑΒΓΔΕΖΗΘΙΚΛΜΝΞΟΠΡΣΤΥΦΧΨΩ"
                android:gravity="center_horizontal"
                android:inputType="text"
                android:padding="5dp"
                android:text="Examiner's Name"
                android:textSize="18dp"
                android:textStyle="bold"
                android:typeface="serif" />
        </TableRow>
    </TableLayout>


<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="60dp"
    android:layout_weight="0.01"
    android:orientation="horizontal">

    <TextView
        android:id="@+id/textView2"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="5"
        android:gravity="center_horizontal"
        android:text="Student's Name"
        android:textStyle="bold"
        android:typeface="serif" />

    <TextView
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="5"
        android:gravity="center_horizontal"
        android:text="User Interface"
        android:textStyle="bold"
        android:typeface="serif"
        android:layout_marginLeft="5dp"/>

    <TextView
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="5"
        android:gravity="center_horizontal"
        android:text="Functions"
        android:textStyle="bold"
        android:typeface="serif"
        android:layout_marginLeft="5dp"/>

    <TextView
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="5"
        android:gravity="center_horizontal"
        android:text="User Manual"
        android:textStyle="bold"
        android:typeface="serif"
        android:layout_marginLeft="5dp"/>

    <TextView
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="5"
        android:gravity="center_horizontal"
        android:text="AVG"
        android:textStyle="bold"
        android:typeface="serif"/>

    <TextView
        android:layout_height="match_parent"
        android:layout_weight="2.35"
        android:gravity="left"
        android:layout_marginLeft="5dp"
        android:layout_width="wrap_content" />
    </LinearLayout>


<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:layout_weight="0.01"
    android:orientation="horizontal">

    <EditText
        android:id="@+id/word_edit_text"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="5"
        android:digits="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZαβγδεζηθικλμνξοπρστυφχψωΑΒΓΔΕΖΗΘΙΚΛΜΝΞΟΠΡΣΤΥΦΧΨΩ"
        android:gravity="center_horizontal"
        android:inputType="text" />

    <EditText
        android:id="@+id/number_edit_text1"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="5"
        android:gravity="center_horizontal"
        android:inputType="number" />

    <EditText
        android:id="@+id/number_edit_text2"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="5"
        android:gravity="center_horizontal"
        android:inputType="number" />

    <EditText
        android:id="@+id/number_edit_text3"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="5"
        android:gravity="center_horizontal"
        android:inputType="number" />

    <TextView
        android:id="@+id/number_text_view"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="5"
        android:gravity="center_horizontal"
        android:textSize="18dp"
        android:textStyle="bold"
        android:typeface="serif"
        android:layout_marginTop="9dp"/>

    <Button
        android:id="@+id/delete_button"
        android:layout_width="0dp"
        android:layout_height="40dp"
        android:layout_weight="2.15"
        android:background="@android:drawable/ic_delete"
        android:onClick="onDelete" />
</LinearLayout>

<Button
        android:id="@+id/add_field_button"
        android:layout_width="100dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_marginBottom="5dp"
        android:layout_marginLeft="5dp"
        android:layout_marginRight="5dp"
        android:background="#555"
        android:onClick="onAddField"
        android:paddingLeft="5dp"
        android:text="Add Field"
        android:textColor="#FFF" />
</LinearLayout>

和field.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="50dp"
android:orientation="horizontal"
android:layout_weight="0.01">

<EditText
    android:id="@+id/number_edit_text"
    android:layout_width="0dp"
    android:layout_height="match_parent"
    android:layout_weight="5"
    android:inputType="textCapWords"
    android:gravity="center_horizontal" />
<EditText
    android:id="@+id/number_edit_text1"
    android:layout_width="0dp"
    android:layout_height="match_parent"
    android:layout_weight="5"
    android:inputType="textCapWords"
    android:gravity="center_horizontal" />
<EditText
    android:id="@+id/number_edit_text2"
    android:layout_width="0dp"
    android:layout_height="match_parent"
    android:layout_weight="5"
    android:inputType="textCapWords"
    android:gravity="center_horizontal" />
<EditText
    android:id="@+id/number_edit_text3"
    android:layout_width="0dp"
    android:layout_height="match_parent"
    android:layout_weight="5"
    android:inputType="textCapWords"
    android:gravity="center_horizontal" />
<TextView
    android:id="@+id/number_text_view"
    android:layout_width="0dp"
    android:layout_height="match_parent"
    android:layout_weight="5"
    android:gravity="center_horizontal"
    android:textSize="18dp"
    android:textStyle="bold"
    android:typeface="serif"
    android:layout_marginTop="9dp"/>


<Button
    android:id="@+id/delete_button"
    android:layout_width="0dp"
    android:layout_height="40dp"
    android:layout_weight="2.15"
    android:background="@android:drawable/ic_delete"
    android:onClick="onDelete" />

</LinearLayout>

提前致谢!

Answer 1

这是适合您的工作代码:

public void onAddField(View v) {
    LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    final View rowView = inflater.inflate(R.layout.field, null);
    ((EditText) rowView.findViewById(R.id.number_edit_text1)).addTextChangedListener(new TextWatcher() {

        public void beforeTextChanged(CharSequence s, int start, int count,
                                      int after) {
            // TODO Auto-generated method stub
        }

        public void onTextChanged(CharSequence s, int start, int before,
                                  int count) {
            ((TextView) rowView.findViewById(R.id.number_text_view)).setText(
                    avg(((EditText) rowView.findViewById(R.id.number_edit_text1)),
                            ((EditText) rowView.findViewById(R.id.number_edit_text2)),
                            ((EditText) rowView.findViewById(R.id.number_edit_text3))));            }

        public void afterTextChanged(Editable s) {
            // TODO Auto-generated method stub
        }
    });

    ((EditText) rowView.findViewById(R.id.number_edit_text2)).addTextChangedListener(new TextWatcher() {

        public void beforeTextChanged(CharSequence s, int start, int count,
                                      int after) {
            // TODO Auto-generated method stub

        }

        public void onTextChanged(CharSequence s, int start, int before,
                                  int count) {
            ((TextView) rowView.findViewById(R.id.number_text_view)).setText(
                    avg(((EditText) rowView.findViewById(R.id.number_edit_text1)),
                            ((EditText) rowView.findViewById(R.id.number_edit_text2)),
                            ((EditText) rowView.findViewById(R.id.number_edit_text3))));
        }

        public void afterTextChanged(Editable s) {
            // TODO Auto-generated method stub

        }
    });
    ((EditText) rowView.findViewById(R.id.number_edit_text3)).addTextChangedListener(new TextWatcher() {

        public void beforeTextChanged(CharSequence s, int start, int count,
                                      int after) {
            // TODO Auto-generated method stub

        }

        public void onTextChanged(CharSequence s, int start, int before,
                                  int count) {
            ((TextView) rowView.findViewById(R.id.number_text_view)).setText(
                    avg(((EditText) rowView.findViewById(R.id.number_edit_text1)),
                            ((EditText) rowView.findViewById(R.id.number_edit_text2)),
                            ((EditText) rowView.findViewById(R.id.number_edit_text3))));

        }

        public void afterTextChanged(Editable s) {
            // TODO Auto-generated method stub

        }
    });
    // Add the new row before the add field button.
    parentLinearLayout.addView(rowView, parentLinearLayout.getChildCount() - 1);


}

private String avg(EditText viewById, EditText viewById1, EditText viewById2) {
    int number1;
    int number2;
    int number3;
    if (viewById.getText().toString() != "" && viewById.getText().length() > 0) {
        number1 = Integer.parseInt(viewById.getText().toString());
    } else {
        number1 = 0;
    }
    if (viewById1.getText().toString() != "" && viewById1.getText().length() > 0) {
        number2 = Integer.parseInt(viewById1.getText().toString());
    } else {
        number2 = 0;
    }
    if (viewById2.getText().toString() != "" && viewById2.getText().length() > 0) {
        number3 = Integer.parseInt(viewById2.getText().toString());
    } else {
        number3 = 0;
    }

    return Integer.toString((number1 + number2 + number3) / 3);
}

它没有起作用，因为您没有为字段分配任何监听器。

此外，我建议您对要添加的 View 使用 RecyclerView。

注意

avg 函数是新函数，不要替换成你的。

希望对你有帮助:)