Question

我一直在开发一个应用程序，所有代码似乎都很好，xml和java。当我在模拟器中运行该应用程序时，我的启动屏幕不再运行，当我单击一个按钮时，它将带我到正确的页面，但没有显示文件的布局。当我编辑xml文件布局时，更改在模拟器中运行时不会显示在应用程序上。

我将在下面发布代码：

此代码用于页面的xml布局：

<?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:background="@drawable/bgapp"
    tools:context=".complain">

    <ImageView
        android:layout_width="310dp"
        android:layout_height="86dp"
        android:layout_marginLeft="45dp"
        android:src="@drawable/bfcfulllogotransparent" />

    <ImageView
        android:layout_width="79dp"
        android:layout_height="76dp"
        android:layout_marginLeft="160dp"
        android:layout_marginTop="500dp"
        android:src="@drawable/bfchandtransparent"/>

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Making a Complaint"
        android:textAllCaps="false"
        android:layout_marginTop="75dp"
        android:textAlignment="center"
        android:textColor="#ffff"
        android:textStyle="bold"
        android:textSize="18dp"/>

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="100dp"
        android:layout_marginHorizontal="10dp"
        android:textAlignment="center"
        android:textColor="#ffff"
        android:textAllCaps="false"
        android:text="There may be times when you feel that you are not happy with the services you have been provided, it is your right to be able to make a complaint about these issues.
"
        android:fontFamily="sans-serif"
        android:textSize="16dp"/>

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="190dp"
        android:layout_marginHorizontal="10dp"
        android:textAlignment="center"
        android:textColor="#ffff"
        android:textAllCaps="false"
        android:text="There are a number of ways that you can make a complaint…"
        android:fontFamily="sans-serif"
        android:textSize="16dp"/>

    <Button
        android:id="@+id/butthow"
        android:layout_width="273dp"
        android:layout_height="66dp"
        android:layout_marginLeft="55dp"
        android:layout_marginTop="280dp"
        android:background="@drawable/custom_button"
        android:text="How to make a complaint"
        android:textAllCaps="false"
        android:textColor="#ffff"
        android:textSize="18dp"
        android:textStyle="bold"/>

    <Button
        android:id="@+id/buttwhat"
        android:layout_width="273dp"
        android:layout_height="66dp"
        android:layout_marginLeft="55dp"
        android:layout_marginTop="380dp"
        android:background="@drawable/custom_button"
        android:text="What happens to your complaint"
        android:textAllCaps="false"
        android:textColor="#ffff"
        android:textSize="18dp"
        android:textStyle="bold"/>


</RelativeLayout>

此代码用于启动屏幕的xml：

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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:background="@drawable/bgapp"
    tools:context=".splashscreen">

    <TextView
        android:id="@+id/textView3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="3dp"
        android:text="Childrens Guide"
        android:textColor="#ffff"
        android:textSize="35dp"
        android:textStyle="bold"
        app:layout_constraintBottom_toTopOf="@+id/textView4"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/imageView4" />

    <TextView
        android:id="@+id/textView4"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginStart="10dp"
        android:layout_marginEnd="10dp"
        android:layout_marginBottom="214dp"
        android:text="A guide for children living in foster care"
        android:textAlignment="center"
        android:textColor="#ffff"
        android:textSize="20dp"
        android:textStyle="bold"
        app:layout_constraintBottom_toTopOf="@+id/imageView5"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView3" />

    <ImageView
        android:id="@+id/imageView4"
        android:layout_width="350dp"
        android:layout_height="100dp"
        android:layout_marginStart="15dp"
        android:layout_marginTop="27dp"
        android:layout_marginEnd="15dp"
        android:layout_marginBottom="133dp"
        android:src="@drawable/bfcfulllogotransparent"
        app:layout_constraintBottom_toTopOf="@+id/imageView6"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ImageView
        android:id="@+id/imageView5"
        android:layout_width="101dp"
        android:layout_height="0dp"
        android:layout_marginBottom="41dp"
        android:src="@drawable/bfchandtransparent"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView4" />

    <ImageView
        android:id="@+id/imageView6"
        android:layout_width="1000dp"
        android:layout_height="200dp"
        android:layout_marginStart="18dp"
        android:layout_marginEnd="18dp"
        android:layout_marginBottom="173dp"
        android:src="@drawable/coverkids"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/imageView4" />
</androidx.constraintlayout.widget.ConstraintLayout>

这是启动画面的Java：

package com.example.bfcchildrensguidenew;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;

public class splashscreen extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_splashscreen);
        Thread myThread = new Thread() {
            @Override
            public void run() {
                try {
                    sleep(3000 );
                    Intent intent = new Intent(getApplicationContext(), MainActivity.class);
                    startActivity(intent);
                    finish();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }

        };
        myThread.start();
    }
}

Answer 1

您不能在主线程（UI线程）之外调用startActivity方法，它将崩溃。用户处理程序改为线程。

Handler handler = new Handler(Looper.getMainLooper());
   handler.post(new Runnable() {
   @Override
      public void run() {
          Intent intent = new Intent (getApplicationContext(),MainActivity.this);
          startActivity(intent);
      }
   });

xml布局不会显示在模拟器上

1 个答案: