Android应用程序在我从android工作室运行手机时崩溃。

Question

我是一个编程初学者，并试图在android中处理一个示例项目，但当我在手机上运行它时，我的应用程序就崩溃了。

请帮帮我。我们能做些什么？

当我签入logcat时，我会收到这个错误。

01-06 13:18:20.778 13471-13471/? E/AndroidRuntime: FATAL EXCEPTION: main
                                                   Process: com.hof_university.chethan.chatmessenger, PID: 13471
                                                   java.lang.NoSuchMethodError: No static method getFont(Landroid/content/Context;ILandroid/util/TypedValue;ILandroid/widget/TextView;)Landroid/graphics/Typeface; in class Landroid/support/v4/content/res/ResourcesCompat; or its super classes (declaration of 'android.support.v4.content.res.ResourcesCompat' appears in /data/app/com.hof_university.chethan.chatmessenger-2/split_lib_dependencies_apk.apk)
                                                       at android.support.v7.widget.TintTypedArray.getFont(TintTypedArray.java:119)
                                                       at android.support.v7.widget.AppCompatTextHelper.updateTypefaceAndStyle(AppCompatTextHelper.java:208)
                                                       at android.support.v7.widget.AppCompatTextHelper.loadFromAttributes(AppCompatTextHelper.java:110)
                                                       at android.support.v7.widget.AppCompatTextHelperV17.loadFromAttributes(AppCompatTextHelperV17.java:38)
                                                       at android.support.v7.widget.AppCompatTextView.<init>(AppCompatTextView.java:81)
                                                       at android.support.v7.widget.AppCompatTextView.<init>(AppCompatTextView.java:71)
                                                       at android.support.v7.widget.AppCompatTextView.<init>(AppCompatTextView.java:67)
                                                       at android.support.v7.widget.Toolbar.setTitle(Toolbar.java:753)
                                                       at android.support.v7.widget.ToolbarWidgetWrapper.setTitleInt(ToolbarWidgetWrapper.java:261)
                                                       at android.support.v7.widget.ToolbarWidgetWrapper.setWindowTitle(ToolbarWidgetWrapper.java:243)
                                                       at android.support.v7.widget.ActionBarOverlayLayout.setWindowTitle(ActionBarOverlayLayout.java:621)
                                                       at android.support.v7.app.AppCompatDelegateImplV9.onTitleChanged(AppCompatDelegateImplV9.java:631)
                                                       at android.support.v7.app.AppCompatDelegateImplV9.ensureSubDecor(AppCompatDelegateImplV9.java:328)
                                                       at android.support.v7.app.AppCompatDelegateImplV9.setContentView(AppCompatDelegateImplV9.java:284)
                                                       at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:139)
                                                       at com.hof_university.chethan.chatmessenger.MainActivity.onCreate(MainActivity.java:19)
                                                       at android.app.Activity.performCreate(Activity.java:6177)
                                                       at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1112)
                                                       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2541)
                                                       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2685)
                                                       at android.app.ActivityThread.access$900(ActivityThread.java:188)
                                                       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1530)
                                                       at android.os.Handler.dispatchMessage(Handler.java:111)
                                                       at android.os.Looper.loop(Looper.java:210)
                                                       at android.app.ActivityThread.main(ActivityThread.java:5839)
                                                       at java.lang.reflect.Method.invoke(Native Method)
                                                       at java.lang.reflect.Method.invoke(Method.java:372)
                                                       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1113)
                                                       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:879)

MainActivity

public class MainActivity extends AppCompatActivity {

private EditText editMessage;
private DatabaseReference mDatabase;

@Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);
    editMessage = (EditText) findViewById(R.id.editMessageE);
    mDatabase = FirebaseDatabase.getInstance().getReference().child("Messages");
}

public void sendButtonClicked(View view){
    final String messageValue = editMessage.getText().toString().trim();
    if (!TextUtils.isEmpty(messageValue)){
        final DatabaseReference newPost = mDatabase.push();
        newPost.child("content").setValue(messageValue);
    }
}
}

Answer 1

尝尝这个

 implementation 'com.android.support:recyclerview-v7:27.0.2'
 implementation 'com.android.support:appcompat-v7:27.0.2'

还有这个

buildToolsVersion 27.0.2
compileSdkVersion 27.0.2

Answer 2

我查看了正式文档，getFont这个方法是在api 27之后添加的，需要在build.gradle文件中添加com.android.support:support-compat:27.0.0。它属于ResourcesCompat

ResourcesCompat

android doc getFont