如何将ImageView定位在不同屏幕尺寸的相同位置？

Question

我一直在研究一个简单的Android应用程序来计算一个人的身体质量指数，我已经将所有功能都工作了但是将箭头放在与用户屏幕大小相对应的颜色条中的正确位置就是我所坚持的。我通过设置箭头ImageView的X和Y值来工作，但是当我在不同的屏幕尺寸中测试我的应用程序时，显然箭头的位置会发生变化，即使我将dp值转换为像素。如何定位箭头ImageView以使其在不同的屏幕尺寸中保持不变？

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="coding.guillermo.bmiapp.MainActivity2"
tools:showIn="@layout/activity_main2"
android:clickable="false"
android:background="#ffffff"
android:id="@+id/relativeLayout">


<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="BMI"
    android:id="@+id/bmiText"
    android:textSize="25dp"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="21.24"
    android:id="@+id/bmiResult"
    android:textSize="30dp"
    android:layout_below="@+id/bmiText"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="22dp" />



<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/bmiCategory"
    android:textSize="25dp"
    android:text="Normal weight"
    android:layout_marginTop="22dp"
    android:layout_below="@+id/bmiResult"
    android:layout_centerHorizontal="true" />


<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Save result"
    android:id="@+id/saveButton"
    android:backgroundTint="@color/toolBarColor"
    android:textColor="#ffffff"
    android:layout_marginBottom="20dp"
    android:layout_alignParentBottom="true"
    android:layout_alignParentEnd="true" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="BMI Log"
    android:id="@+id/trackerButton2"
    android:backgroundTint="@color/toolBarColor"
    android:textColor="#ffffff"
    android:layout_alignTop="@+id/saveButton" />

<ImageView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/imageView"
    android:background="@drawable/bmibar"
    android:layout_marginTop="36dp"
    android:layout_below="@+id/bmiCategory" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Underweight &lt;18.50 "
    android:id="@+id/underweightText"
    android:textSize="22sp"
    android:layout_below="@+id/imageView"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="33dp" />
<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Normal 18.5 - 24.99"
    android:id="@+id/normalText"
    android:textSize="22sp"
    android:paddingTop="5dp"
    android:layout_below="@+id/underweightText"
    android:layout_alignStart="@+id/underweightText" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Overweight >=25.00"
    android:id="@+id/overweightText"
    android:layout_below="@+id/normalText"
    android:textSize="22sp"
    android:paddingTop="5dp"
    android:layout_alignStart="@+id/normalText" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Obese >=30.00"
    android:id="@+id/obeseText"
    android:textSize="22sp"
    android:paddingTop="5dp"
    android:layout_below="@+id/overweightText"
    android:layout_alignStart="@+id/overweightText" />

public class MainActivity2 extends AppCompatActivity {
 TextView resultText,bmiLabel,underWeightText,normalText,overweightText,obeseText;
RelativeLayout.LayoutParams params;
Button saveButton,trackerButton;
Result result;
EditText userName;
DBhandler dbHandler;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main2);
    // TextViews
    resultText = (TextView) findViewById(R.id.bmiResult);
    bmiLabel = (TextView) findViewById(R.id.bmiCategory);
    underWeightText = (TextView) findViewById(R.id.underweightText);
    normalText = (TextView) findViewById(R.id.normalText);
    overweightText = (TextView) findViewById(R.id.overweightText);
    obeseText = (TextView) findViewById(R.id.obeseText);
    // Button
    saveButton = (Button) findViewById(R.id.saveButton);
    trackerButton = (Button) findViewById(R.id.trackerButton2);
    // Getting User object from the previous activity
    result = (Result) getIntent().getParcelableExtra("result");
    // Database
    dbHandler = new DBhandler(this);

    // Displaying the arrow in the corresponding place
    ImageView arrow = new ImageView(this);
    params = new RelativeLayout.LayoutParams(80,80);
    arrow.setImageResource(R.drawable.arrow2);
    RelativeLayout rl = (RelativeLayout) findViewById(R.id.relativeLayout);

   // the display of the arrow is different when tested in device's with different screen sizes
    int dpValue = 0;
    int dpValue2 = 166;
    float d = getApplicationContext().getResources().getDisplayMetrics().density;
    int margin = (int)(dpValue * d);
    int margin2 = (int) (dpValue2 * d);

    arrow.setX(margin);
    arrow.setY(margin2);
    rl.addView(arrow);

    // BMI diplay
    resultText.setText(Double.toString(result.getBMI()));
    bmiLabel.setText(result.getBmiCategory());
    // BMI category bold display
    bmiCategoryBold(result.getBMI());

    // Saving result to internal storage for later retrieval
    saveButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            View view = (LayoutInflater.from(MainActivity2.this)).inflate(R.layout.alert_content,null);
            AlertDialog.Builder alertBuilder = new AlertDialog.Builder(MainActivity2.this);
            alertBuilder.setView(view);
            userName = (EditText) view.findViewById(R.id.nameInput);
            SimpleDateFormat dateFormat = new SimpleDateFormat("MM/dd/yyyy");
            String date = dateFormat.format(new Date());
            result.setDate(date);
            alertBuilder.setCancelable(true).setPositiveButton("Ok", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
            result.setName(userName.getText().toString());
            // adding result to the SQLite database
            dbHandler.addResult(result);
            Toast toast = Toast.makeText(getApplicationContext(),"result saved",Toast.LENGTH_SHORT);
            toast.show();

                }
            });
            AlertDialog dialog = alertBuilder.create();
            dialog.show();
            Button nButton = dialog.getButton(DialogInterface.BUTTON_POSITIVE);
            nButton.setBackgroundColor(getResources().getColor(R.color.toolBarColor));
            nButton.setTextColor(Color.WHITE);

        }
    });

    trackerButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent(getApplicationContext(),MainActivity3.class);
            startActivity(intent);
        }
    });

}


public void bmiCategoryBold(double bmi){
    if(bmi < 18.50){
        underWeightText.setTypeface(null, Typeface.BOLD);
    }
    else if(bmi <= 24.99){
        normalText.setTypeface(null,Typeface.BOLD);
    }
    else if(bmi<=29.99){
        overweightText.setTypeface(null,Typeface.BOLD);
    }
    else{
        obeseText.setTypeface(null,Typeface.BOLD);
    }
}

}

第一张照片是在1080像素×1920像素的屏幕上运行的应用程序，第二张是1440像素乘2560像素的屏幕

first pic

second pic

Answer 1

将Linearlayout添加为子视图的子显示，使用其方向和重力属性，您可以轻松地以更优化的方式获得设计，并适合于屏幕尺寸。 在这里，我使用RelativeLayout作为Parent和LinearLayout作为子视图的子父。

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:orientation="vertical"
        android:padding="10dp">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:orientation="vertical">

            <TextView
                android:id="@+id/bmiText"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="BMI"
                android:textSize="25dp" />

            <TextView
                android:id="@+id/bmiResult"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:padding="5dp"
                android:text="21.24"
                android:textSize="30dp" />


            <TextView
                android:id="@+id/bmiCategory"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Normal weight"
                android:textSize="25dp" />


        </LinearLayout>

        <ImageView
            android:id="@+id/imageView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@mipmap/ic_launcher" />

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:orientation="vertical"
            android:padding="5dp">

            <TextView
                android:id="@+id/underweightText"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:padding="10dp"
                android:text="Underweight &lt;18.50 "
                android:textSize="22sp" />

            <TextView
                android:id="@+id/normalText"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:padding="10dp"
                android:text="Normal 18.5 - 24.99"
                android:textSize="22sp" />

            <TextView
                android:id="@+id/overweightText"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:padding="10dp"
                android:text="Overweight >=25.00"
                android:textSize="22sp" />

            <TextView
                android:id="@+id/obeseText"
                android:layout_width="wrap_content"
                android:padding="10dp"
                android:layout_height="wrap_content"
                android:text="Obese >=30.00"
                android:textSize="22sp" />


        </LinearLayout>


        <LinearLayout
            android:layout_width="match_parent"
            android:orientation="horizontal"
            android:layout_height="wrap_content">

            <LinearLayout
                android:layout_width="match_parent"
                android:gravity="left"
                android:layout_height="wrap_content">

                <Button
                    android:id="@+id/trackerButton2"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:backgroundTint="#000000"
                    android:text="BMI Log"
                    android:gravity="center"
                    android:textColor="#ffffff" />

                <LinearLayout
                    android:layout_width="match_parent"
                    android:gravity="right"
                    android:layout_height="wrap_content">
                    <Button
                        android:id="@+id/saveButton"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:gravity="center"
                        android:backgroundTint="#000000"
                        android:text="Save result"
                        android:textColor="#ffffff" />


                </LinearLayout>


            </LinearLayout>

        </LinearLayout>
    </LinearLayout>
</RelativeLayout>

尽量避免上下边缘过多。