Question

在这里，我尝试在按钮单击事件中从 MainActivity 打开一个名为 LevelActivity 的活动，但是当我尝试打开我的LevelActivity时，它使我离开了应用程序。 XML 和 JAVA 文件如下。

我的LevelActivity.java

public class LevelActivity extends AppCompatActivity {

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

    Button btnEasy = (Button) findViewById(R.id.btnEasy);
    Button btnHard = (Button) findViewById(R.id.btnHard);
    Button btnNormal = (Button) findViewById(R.id.btnNormal);

    btnEasy.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            int seconds = 120;
            int Live = 10;
            Intent myIntent = new Intent(LevelActivity.this, GameActivity.class);
            myIntent.putExtra("varSeconds", seconds);
            myIntent.putExtra("varLive", Live);
            startActivity(myIntent);
        }
    });


    btnHard.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            int seconds = 60;
            int Lives = 5;
            Intent myIntent = new Intent(LevelActivity.this, GameActivity.class);
            myIntent.putExtra("varSeconds", seconds);
            myIntent.putExtra("varLive", Lives);
            startActivity(myIntent);
        }
    });


    btnNormal.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            int seconds = 60;
            int Live = 10;
            Intent myIntent = new Intent(LevelActivity.this, GameActivity.class);
            myIntent.putExtra("varSeconds", seconds);
            myIntent.putExtra("varLive", Live);
            startActivity(myIntent);
        }
    });

}}

ActivityMain.java的代码

这是我的主要活动，如我之前所说，我想从主要活动导航到关卡活动

public class MainActivity extends AppCompatActivity {

ImageButton btnMathPlay, btnMathShare, btnMathRate;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    btnMathPlay = (ImageButton) findViewById(R.id.btnMathPlay);
    btnMathShare= (ImageButton) findViewById(R.id.btnMathShare);
    btnMathRate = (ImageButton) findViewById(R.id.btnMathRate);

    btnMathPlay.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            /*
             *  Example of Explicit Intent
             *  When you click Play Button on the screen
             *  Game Activity will be started
             */

            Intent i = new Intent(MainActivity.this,LevelActivity.class);
            startActivity(i);
        }
    });

    btnMathShare.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            /*
             *  Example of Implict Intent
             *  When you click Share Button on the screen
             *  Android will find the activities that allow to share messages.
             */

            Intent intent = new Intent(Intent.ACTION_SEND);
            intent.setType("text/plain");
            intent.putExtra(Intent.EXTRA_TEXT, "Just Maths - Fun way to learn Maths. http://www.play.google.com");
            startActivity(intent);
        }
    });

    btnMathRate.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            /*
             *  Simple Toast Message To Display Message For Short Duration
             *  Link that to your app landing page.
             */
            Toast.makeText(MainActivity.this,"You can open your Google Play landing page",Toast.LENGTH_LONG).show();
        }
    });
}}

这是我用于LevelActivity的XML文件

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/colorAccent"
tools:context=".LevelActivity"
tools:layout_editor_absoluteY="25dp">

<Button
    android:id="@+id/btnEasy"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="134dp"
    android:text="Easy" />

<Button
    android:id="@+id/btnNormal"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/btnEasy"
    android:layout_alignStart="@+id/btnEasy"
    android:layout_alignLeft="@+id/btnEasy"
    android:layout_marginStart="0dp"
    android:layout_marginLeft="@+id/btnEasy"
    android:layout_marginTop="35dp"
    android:text="Normal" />

<Button
    android:id="@+id/btnHard"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/btnNormal"
    android:layout_alignStart="@+id/btnEasy"
    android:layout_alignLeft="@+id/btnEasy"
    android:layout_alignParentBottom="true"

    android:layout_marginTop="36dp"
    android:layout_marginBottom="220dp"
    android:text="Hard" />
    </RelativeLayout>

请帮助我解决此问题，如果您还需要其他类似cat log的文件，请提及！

这是我在调试控制台上找到的内容 希望如此对您有帮助

E/AndroidRuntime: FATAL EXCEPTION: main
Process: cheezycode.com.justmaths, PID: 1634
java.lang.RuntimeException: Unable to start activity ComponentInfo{cheezycode.com.justmaths/cheezycode.com.justmaths.LevelActivity}: android.view.InflateException: Binary XML file line #19: Can't convert to dimension: type=0x12
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2487)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2547)
    at android.app.ActivityThread.access$1100(ActivityThread.java:151)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1398)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:157)
    at android.app.ActivityThread.main(ActivityThread.java:5604)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:774)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:652)
 Caused by: android.view.InflateException: Binary XML file line #19: Can't convert to dimension: type=0x12
    at android.view.LayoutInflater.inflate(LayoutInflater.java:543)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:427)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
    at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:256)
    at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:109)
    at cheezycode.com.justmaths.LevelActivity.onCreate(LevelActivity.java:14)
    at android.app.Activity.performCreate(Activity.java:6358)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1108)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2440)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2547) 
    at android.app.ActivityThread.access$1100(ActivityThread.java:151) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1398) 
    at android.os.Handler.dispatchMessage(Handler.java:102) 
    at android.os.Looper.loop(Looper.java:157) 
    at android.app.ActivityThread.main(ActivityThread.java:5604) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:774) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:652) 
 Caused by: java.lang.UnsupportedOperationException: Can't convert to dimension: type=0x12
    at android.content.res.TypedArray.getDimensionPixelSize(TypedArray.java:668)
    at android.view.ViewGroup$MarginLayoutParams.<init>(ViewGroup.java:7086)
    at android.widget.RelativeLayout$LayoutParams.<init>(RelativeLayout.java:1241)
    at android.widget.RelativeLayout.generateLayoutParams(RelativeLayout.java:1087)
    at 
  android.widget.RelativeLayout.generateLayoutParams(RelativeLayout.java:84)
    at android.view.LayoutInflater.rInflate(LayoutInflater.java:841)
    at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:802)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:519)

Answer 1

这是错误的地方：

android:layout_marginLeft="@+id/btnEasy"

边距应该是数字，而不是视图。

如果您打算将其放置在该视图旁边，请使用：

android:layout_toLeftOf="@id/btnEasy"

同样，每次引用现有视图时，也不应包含+符号。仅当您在其ID属性上命名新视图时，这种情况才会发生。

Answer 2

最后，在造成了很多混乱之后，我再次重写了所有代码，并找出一些错误并使用此代码对LevelActivity进行了更改

var orders = from o in suborder.OrderLineItemList
             where
               o.Product == "Shoes" ||
               o.BundleComponentList.Any(c => c.Product == "Shoes")
             select o;

bool isShoesOrder = orders.Any();

按下按钮后活动被关闭

2 个答案: