关于snackBar 的非法状态异常

Question

我在编译小吃店时遇到了非法状态异常。 App 的结果是我可以执行第一个按钮，但是一旦我尝试使用我的第二个按钮，应用程序就会崩溃。 代码和错误信息如下所示：

public void callIntent(View view) {
    Intent intent = null;
    switch (view.getId()) {
        case R.id.ZhaoDisplay:
            Toast toast = Toast.makeText(getApplicationContext(),
                    "Zhao Wang, 991556434; Website Name: Amazon", Toast.LENGTH_SHORT);
            toast.show();
            intent = new Intent(Intent.ACTION_VIEW,
                    Uri.parse("https://www.amazon.ca"));
            startActivity(intent);
            break;

        case R.id.WangDisplay:

            intent = new Intent(this, WangActivity.class);
            //TextMulti

            editInput = (EditText)findViewById(R.id.TextMulti);
            String userInput = editInput.getText().toString();
            intent.putExtra("valueFromUser", userInput);

            Snackbar snackbar = null;
            snackbar = Snackbar.make(findViewById(R.id.content),
                    "My Second Screen_Zhao Wang 991556434", 10);
            snackbar.show();

            startActivity(intent);
            break;

        default:
            break;
    }




     E/AndroidRuntime: FATAL EXCEPTION: main
Process: zhao.wang.s991556434, PID: 15778
java.lang.IllegalStateException: Could not execute method for android:onClick
    at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:414)
    at android.view.View.performClick(View.java:7125)
    at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:992)
    at android.view.View.performClickInternal(View.java:7102)
    at android.view.View.access$3500(View.java:801)
    at android.view.View$PerformClick.run(View.java:27336)
    at android.os.Handler.handleCallback(Handler.java:883)
    at android.os.Handler.dispatchMessage(Handler.java:100)
    at android.os.Looper.loop(Looper.java:214)
    at android.app.ActivityThread.main(ActivityThread.java:7356)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
 Caused by: java.lang.reflect.InvocationTargetException
    at java.lang.reflect.Method.invoke(Native Method)
    at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:409)
    at android.view.View.performClick(View.java:7125) 
    at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:992) 
    at android.view.View.performClickInternal(View.java:7102) 
    at android.view.View.access$3500(View.java:801) 
    at android.view.View$PerformClick.run(View.java:27336) 
    at android.os.Handler.handleCallback(Handler.java:883) 
    at android.os.Handler.dispatchMessage(Handler.java:100) 
    at android.os.Looper.loop(Looper.java:214) 
    at android.app.ActivityThread.main(ActivityThread.java:7356) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930) 
 Caused by: java.lang.IllegalArgumentException: No suitable parent found from the given view. Please provide a valid view.
    at com.google.android.material.snackbar.Snackbar.make(Snackbar.java:158)
    at zhao.wang.s991556434.ZhaoActivity.callIntent(ZhaoActivity.java:60)
    at java.lang.reflect.Method.invoke(Native Method) 
     

我试图将小吃条代码部分放入我的第二个活动并编译它，但它显示了相同的错误。我可以就此寻求帮助吗？谢谢。

Answer 1

问题在于为snackbar make 方法传递了错误的视图，请尝试以下方法

snackbar = Snackbar.make(findViewById(android.R.id.content),
                    "My Second Screen_Zhao Wang 991556434", 10);
            snackbar.show();