修复 Gridlayout 投射到 ImageView 的错误

Question

我将 .xml 文件设置为

<GridLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerVertical="true"
    android:layout_centerHorizontal="true"
    android:columnCount="4"
    android:rowCount="6"
    android:onClick="dropIn"
    android:layout_alignParentEnd="true"
    android:id="@+id/gridLayout">

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="80dp"
        android:layout_height="70dp"
        android:layout_column="0"
        tools:layout_editor_absoluteX="288dp"
        tools:layout_editor_absoluteY="180dp"
        android:layout_row="0"
        android:onClick="dropIn"
        android:contentDescription="@null"
        android:tag="1"
        app:srcCompat="@drawable/stone" />

无论如何，我有更多的 ImageView，而使它们与众不同的是 ID 和标签。我决定让代码通过标签识别它们。所以这就是我目前拥有的：

int[] gameState = {2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2};

public void dropIn(View view) {

    ImageView counter = (ImageView) view;
    counter.setImageResource(R.drawable.stone);

    int tappedCounter = Integer.parseInt(counter.getTag().toString());
    try {
        if (gameState[tappedCounter] == 2 && gameIsActive) {

            gameState[tappedCounter] = 3;
            countMe = countMe - 1;
            counter.setVisibility(View.INVISIBLE);
        } else if (gameState[tappedCounter] == 3 && gameIsActive) {

            Toast.makeText(MainActivity.this, "That field is already played!",
                    Toast.LENGTH_SHORT).show();
        }
    } catch (Exception e) {
        Toast.makeText(MainActivity.this, "Oho!",
                Toast.LENGTH_SHORT).show();
        e.printStackTrace();
    }

这一切工作正常，除了当我点击一个已经被点击但现在不可见的 ImageView 时，它使应用程序崩溃并显示以下消息：

E/AndroidRuntime: FATAL EXCEPTION: main
              Process: com.nedim.lastonestanding, PID: 9758
              java.lang.IllegalStateException: Could not execute method for android:onClick
                  at android.view.View$DeclaredOnClickListener.onClick(View.java:5374)
                  at android.view.View.performClick(View.java:6294)
                  at android.view.View$PerformClick.run(View.java:24770)
                  at android.os.Handler.handleCallback(Handler.java:790)
                  at android.os.Handler.dispatchMessage(Handler.java:99)
                  at android.os.Looper.loop(Looper.java:164)
                  at android.app.ActivityThread.main(ActivityThread.java:6494)
                  at java.lang.reflect.Method.invoke(Native Method)
                  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
               Caused by: java.lang.reflect.InvocationTargetException
                  at java.lang.reflect.Method.invoke(Native Method)
                  at android.view.View$DeclaredOnClickListener.onClick(View.java:5369)
                  at android.view.View.performClick(View.java:6294) 
                  at android.view.View$PerformClick.run(View.java:24770) 
                  at android.os.Handler.handleCallback(Handler.java:790) 
                  at android.os.Handler.dispatchMessage(Handler.java:99) 
                  at android.os.Looper.loop(Looper.java:164) 
                  at android.app.ActivityThread.main(ActivityThread.java:6494) 
                  at java.lang.reflect.Method.invoke(Native Method) 
                  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438) 
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807) 
               Caused by: java.lang.ClassCastException: android.widget.GridLayout cannot be cast to android.widget.ImageView
                  at com.nedim.lastonestanding.MainActivity.dropIn(MainActivity.java:32)
                  at java.lang.reflect.Method.invoke(Native Method) 
                  at android.view.View$DeclaredOnClickListener.onClick(View.java:5369) 
                  at android.view.View.performClick(View.java:6294) 
                  at android.view.View$PerformClick.run(View.java:24770) 
                  at android.os.Handler.handleCallback(Handler.java:790) 
                  at android.os.Handler.dispatchMessage(Handler.java:99) 
                  at android.os.Looper.loop(Looper.java:164) 
                  at android.app.ActivityThread.main(ActivityThread.java:6494) 
                  at java.lang.reflect.Method.invoke(Native Method) 
                  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438) 
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807) 
Application terminated.

据我所知，ImageView 中的图像消失了，现在我点击的是 GridLayout 而不是 ImageView，这导致它崩溃，因为它不是问题所在我想与之合作。我还认为问题是计数器使所有视图都变成 ImageViews，但我不确定如何解决这个问题。有任何想法吗？谢谢！

编辑：onCreate 方法

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

    TextView winMessage = findViewById(R.id.winMessage);
    winMessage.setText("Let's play! It's Player " + activePlayer + "'s turn.");
}

Answer 1

传递给 dropIn 函数的 view 是一个 GirdLayout，您正试图将其转换为 ImageView。

GridLayout counter = (GridLayout) view;

但是，我看到您也在使用相同的函数来处理 ImageView 的 onClick，但您不能这样做。如果你想使用相同的函数来处理它们，你可以考虑做这样的事情。

public void dropIn(View view) {
    if(view.getId() == R.id.gridLayout) {
        // Handle action for GridLayout click
    } else if(view.getId() == R.id.imageView1) {
        // Handle the actions for ImageView click
    }
}

我个人认为，您将 onClick 错误地放入了 GridLayout。所以只需从 GridLayout xml 中省略 onClick 属性。

<GridLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerVertical="true"
    android:layout_centerHorizontal="true"
    android:columnCount="4"
    android:rowCount="6"
    <!-- android:onClick="dropIn" -->
    android:layout_alignParentEnd="true"
    android:id="@+id/gridLayout">

Answer 2

您为 GridLayout 和 ImageView 声明了相同的属性 android:onClick="dropIn"。第一个导致 ClassCastException 在行 ImageView counter = (ImageView) view;

修复 Gridlayout 投射到 ImageView 的错误

Fixing error with Gridlayout casting to ImageView

java

android

android-imageview

classcastexception