为什么使用下面的android代码不可见布局组件？

Question

我为android布局使用了以下XML代码，但在运行（或安装）代码后，EditText是不可见的。

XML代码:activity_main.XML

<?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:padding="10dp"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/text_view_show_uploads"
        android:layout_width="wrap_content"
        android:layout_height="40dp"
        android:layout_alignParentStart="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentEnd="true"
        android:layout_alignParentRight="true"
        android:layout_marginStart="30dp"
        android:layout_marginLeft="30dp"
        android:layout_marginEnd="30dp"
        android:layout_marginRight="30dp"
        android:gravity="center"
        android:text="Upload Products Images"
        android:textColor="#f00fff"
        android:textSize="25sp" />

    <Button
        android:id="@+id/button_choose_image"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/text_view_show_uploads"
        android:layout_marginTop="50dp"
        android:text="Choose file" />

    <Spinner
        android:id="@+id/spinner2"
        android:layout_width="231dp"
        android:layout_height="45dp"
        android:layout_below="@id/text_view_show_uploads"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="50dp"
        android:layout_toEndOf="@+id/button_choose_image"
        android:layout_toRightOf="@+id/button_choose_image" />

    <ImageView
        android:id="@+id/image_view1"
        android:layout_width="180dp"
        android:layout_height="160dp"
        android:layout_above="@id/progress_bar"
        android:layout_below="@id/spinner2"
        android:layout_alignParentEnd="true"
        android:layout_alignParentRight="true"
        android:layout_marginLeft="10dp"
        android:layout_marginTop="12dp"
        android:layout_marginEnd="210dp"
        android:layout_marginRight="210dp"
        android:layout_marginBottom="331dp" />

    <ImageView
        android:id="@+id/image_view2"
        android:layout_width="180dp"
        android:layout_height="160dp"
        android:layout_above="@id/progress_bar"
        android:layout_below="@id/spinner2"
        android:layout_alignParentEnd="true"
        android:layout_alignParentRight="true"
        android:layout_marginLeft="10dp"
        android:layout_marginTop="172dp"
        android:layout_marginEnd="210dp"
        android:layout_marginRight="210dp"
        android:layout_marginBottom="168dp" />

    <ImageView
        android:id="@+id/image_view3"
        android:layout_width="180dp"
        android:layout_height="160dp"
        android:layout_above="@id/progress_bar"
        android:layout_below="@id/spinner2"
        android:layout_alignParentEnd="true"
        android:layout_alignParentRight="true"
        android:layout_marginLeft="10dp"
        android:layout_marginTop="335dp"
        android:layout_marginEnd="210dp"
        android:layout_marginRight="210dp"
        android:layout_marginBottom="5dp" />

    <ImageView
        android:id="@+id/image_view4"
        android:layout_width="180dp"
        android:layout_height="160dp"
        android:layout_above="@id/progress_bar"
        android:layout_below="@id/spinner2"
        android:layout_alignParentEnd="true"
        android:layout_alignParentRight="true"
        android:layout_marginLeft="10dp"
        android:layout_marginTop="12dp"
        android:layout_marginEnd="-2dp"
        android:layout_marginRight="-2dp"
        android:layout_marginBottom="331dp" />

    <ImageView
        android:id="@+id/image_view5"
        android:layout_width="180dp"
        android:layout_height="160dp"
        android:layout_above="@id/progress_bar"
        android:layout_below="@id/spinner2"
        android:layout_alignParentEnd="true"
        android:layout_alignParentRight="true"
        android:layout_marginLeft="10dp"
        android:layout_marginTop="172dp"
        android:layout_marginEnd="-2dp"
        android:layout_marginRight="-2dp"
        android:layout_marginBottom="168dp" />

    <ImageView
        android:id="@+id/image_view6"
        android:layout_width="180dp"
        android:layout_height="160dp"
        android:layout_above="@id/progress_bar"
        android:layout_below="@id/spinner2"
        android:layout_alignParentEnd="true"
        android:layout_alignParentRight="true"
        android:layout_marginLeft="10dp"
        android:layout_marginTop="335dp"
        android:layout_marginEnd="-2dp"
        android:layout_marginRight="-2dp"
        android:layout_marginBottom="5dp" />

    <ProgressBar
        android:id="@+id/progress_bar"
        style="@style/Widget.AppCompat.ProgressBar.Horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_above="@+id/button_upload"
        android:layout_marginBottom="16dp" />

    <Button
        android:id="@+id/button_upload"
        android:layout_width="149dp"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_alignParentBottom="true"
        android:layout_marginStart="60dp"
        android:layout_marginLeft="60dp"
        android:layout_marginRight="10dp"
        android:layout_marginBottom="13dp"
        android:layout_toEndOf="@+id/edit_ID_name"
        android:layout_toRightOf="@+id/edit_ID_name"
        android:text="Upload" />

    <EditText
        android:id="@+id/edit_ID_name"
        android:layout_width="150dp"
        android:layout_height="wrap_content"
        android:layout_below="@id/text_view_show_uploads"
        android:layout_marginLeft="10dp"
        android:layout_marginTop="611dp"
        android:layout_marginBottom="7dp"
        android:hint="Enter Product Id" />
</RelativeLayout>

运行最后一个布局组件（EditText）后不可见。相关Java代码：mainactivity.java

package com.example.image_view_from_gallery;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;
import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    Button mButtonChooseImage;
    ImageView mImageView1;
    ImageView mImageView2;
    ImageView mImageView3;
    ImageView mImageView4;
    ImageView mImageView5;
    ImageView mImageView6;
    int PICK_IMAGE_MULTIPLE = 1;
    TextView total;
    ArrayList<Uri> uris;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mButtonChooseImage = findViewById(R.id.button_choose_image);
        total = findViewById(R.id.text);
        mImageView1 = findViewById(R.id.image_view1);
        mImageView2 = findViewById(R.id.image_view2);
        mImageView3 = findViewById(R.id.image_view3);
        mImageView4 = findViewById(R.id.image_view4);
        mImageView5 = findViewById(R.id.image_view5);
        mImageView6 = findViewById(R.id.image_view6);

        uris = new ArrayList<Uri>();

        mButtonChooseImage.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {                 // initialising intent
                Intent intent = new Intent();                 // setting type to select to be image
                intent.setType("image/*");                 // allowing multiple image to be selected
                intent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);
                intent.setAction(Intent.ACTION_GET_CONTENT);
                startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_IMAGE_MULTIPLE);
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);         // When an Image is picked
        if (requestCode == PICK_IMAGE_MULTIPLE && resultCode == RESULT_OK && null != data) {             // Get the Image from data
            if (data.getClipData() != null) {
//                ClipData mClipData = data.getClipData();
                int cout = data.getClipData().getItemCount();
                for (int i = 0; i < cout; i++) {                    // adding imageuri in array
                    Uri imageurl = data.getClipData().getItemAt(i).getUri();
                    uris.add(imageurl);
                }                // setting 1st selected image into image switcher
                mImageView1.setImageURI(uris.get(0));
                mImageView2.setImageURI(uris.get(1));
                mImageView3.setImageURI(uris.get(2));
                mImageView4.setImageURI(uris.get(3));
                mImageView5.setImageURI(uris.get(4));
                mImageView6.setImageURI(uris.get(5));
            } else {
                Uri imageurl = data.getData();
                uris.add(imageurl);
                mImageView1.setImageURI(uris.get(0));
            }
        } else {
            // show this if no image is selected
            Toast.makeText(this, "You haven't picked Image", Toast.LENGTH_LONG).show();
        }
    }
}

为什么在物理设备上安装后编辑文本不可见？

Answer 1

可能是因为您的edittext中的这个android:layout_margintop=“611dp”。它正在走出屏幕。611DP太多了。