我是新来的，执行项目时遇到问题，出现此错误
在此之前，我将“minSdkCompile”从 14 更改为 16，因为我想使用
android:fontFamily 在我的 EditText 中。我不确定这是否是我的错误的原因
找不到符号变量，也找不到解决方案
:app:compileDebugJavaWithJavac
我在 stackoverflow 中搜索过，但没有答案。
- 清理项目并重建项目
- 我已经执行了 gradle 同步
- 使缓存无效并重新启动
- 检查更新
- 检查是否使用嵌入式 SDK
这里的错误:
cannot find symbol variable btnlogin canot find symbol variable logincount
org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':app:compileDebugJavaWithJavac'.
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:103)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:73)
at org.gradle.api.internal.tasks.execution.OutputDirectoryCreatingTaskExecuter.execute(OutputDirectoryCreatingTaskExecuter.java:51)
at org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.execute(SkipUpToDateTaskExecuter.java:59)
at org.gradle.api.internal.tasks.execution.ResolveTaskOutputCachingStateExecuter.execute(ResolveTaskOutputCachingStateExecuter.java:54)
at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:59)
at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:101)
at org.gradle.api.internal.tasks.execution.FinalizeInputFilePropertiesTaskExecuter.execute(FinalizeInputFilePropertiesTaskExecuter.java:44)
at org.gradle.api.internal.tasks.execution.CleanupStaleOutputsExecuter.execute(CleanupStaleOutputsExecuter.java:91)
at org.gradle.api.internal.tasks.execution.ResolveTaskArtifactStateTaskExecuter.execute(ResolveTaskArtifactStateTaskExecuter.java:62)
at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:59)
at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:54)
at org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter.execute(ExecuteAtMostOnceTaskExecuter.java:43)
at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:34)
at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker$1.run(DefaultTaskGraphExecuter.java:256)
at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:336)
at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:328)
at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:199)
at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:110)
at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:249)
at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:238)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.processTask(DefaultTaskPlanExecutor.java:123)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.access$200(DefaultTaskPlanExecutor.java:79)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:104)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:98)
at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.execute(DefaultTaskExecutionPlan.java:663)
at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.executeWithTask(DefaultTaskExecutionPlan.java:597)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.run(DefaultTaskPlanExecutor.java:98)
at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63)
at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55)
at java.lang.Thread.run(Thread.java:745)
Caused by: org.gradle.api.internal.tasks.compile.CompilationFailedException: Compilation failed; see the compiler error output for details.
at org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJavaCompiler.java:52)
at org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJavaCompiler.java:37)
at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.delegateAndHandleErrors(NormalizingJavaCompiler.java:98)
at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:51)
at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:37)
at org.gradle.api.internal.tasks.compile.CleaningJavaCompilerSupport.execute(CleaningJavaCompilerSupport.java:35)
at org.gradle.api.internal.tasks.compile.CleaningJavaCompilerSupport.execute(CleaningJavaCompilerSupport.java:25)
at org.gradle.api.internal.tasks.compile.incremental.IncrementalResultStoringDecorator.execute(IncrementalResultStoringDecorator.java:41)
at org.gradle.api.internal.tasks.compile.incremental.IncrementalResultStoringDecorator.execute(IncrementalResultStoringDecorator.java:27)
at org.gradle.api.internal.tasks.compile.incremental.IncrementalAnnotationProcessingCompiler.execute(IncrementalAnnotationProcessingCompiler.java:50)
at org.gradle.api.internal.tasks.compile.incremental.IncrementalAnnotationProcessingCompiler.execute(IncrementalAnnotationProcessingCompiler.java:36)
at org.gradle.api.tasks.compile.JavaCompile.performCompilation(JavaCompile.java:156)
at org.gradle.api.tasks.compile.JavaCompile.compile(JavaCompile.java:126)
at com.android.build.gradle.tasks.factory.AndroidJavaCompile.compile(AndroidJavaCompile.java:92)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:73)
at org.gradle.api.internal.project.taskfactory.IncrementalTaskAction.doExecute(IncrementalTaskAction.java:50)
at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:39)
at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:26)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$1.run(ExecuteActionsTaskExecuter.java:124)
at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:336)
at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:328)
at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:199)
at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:110)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:113)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:95)
... 33 more
这是我的代码:
MainActivity.java
package com.example.ndarecuy.myapp;
import android.content.Intent;
import android.graphics.Color;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
Button b1;
EditText ed1,ed2;
TextView tx1;
private int counter = 3;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button b2 = findViewById(R.id.btnMhs);
final Button b1 = findViewById(R.id.btnlogin);
final TextView tx1 = findViewById(R.id.logincount);
tx1.setVisibility(View.GONE);
final EditText ed1= findViewById(R.id.txtpassword);
final EditText ed2 = findViewById(R.id.txtusername);
b2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent i = new Intent(getApplicationContext(),Main2Activity.class);
startActivity(i);
}
});
b1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent i = new Intent(getApplicationContext(),MenuProgram.class);
startActivity(i);
if(ed1.getText().toString().equals("admin")&&
ed2.getText().toString().equals("admin")){
Toast.makeText(getApplicationContext(),"berhasil",Toast.LENGTH_SHORT).show();
}
else {
Toast.makeText(getApplicationContext(),"Gagal Login",Toast.LENGTH_SHORT).show();
tx1.setVisibility(View.VISIBLE);
tx1.setBackgroundColor(Color.RED);
counter--;
tx1.setText(Integer.toString(counter));
if (counter==0){
b1.setEnabled(false);
}
}
}
});
}
}
activitymain.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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"
tools:context=".MainActivity"
android:background="@drawable/gradient_animation">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="10dp"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent"
>
<TextView
android:id="@+id/atas"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="LOGIN"
android:textColor="@color/colorWhite"
android:layout_gravity="center_horizontal"
android:textSize="30sp"
/>
<TextView
android:id="@+id/bawah"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/stmik_mercusuar"
android:layout_gravity="center_horizontal"
android:textSize="25sp"
android:textColor="@color/colorWhite"
/>
<ImageView
android:id="@+id/imageView"
android:layout_width="143dp"
android:layout_height="210dp"
app:srcCompat="@mipmap/logo_mercusuar"
android:layout_gravity="center_horizontal"
android:contentDescription="@string/stmik_mercusuar"/>
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textColor="@color/colorAccent"
android:id="@+id/txtusername"
android:hint="@string/username"
android:textColorHint="@color/colorAccent"
android:focusable="true"
android:textColorHighlight="#ff7eff15"
android:fontFamily="sans-serif"
android:inputType="text"
/>
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="@string/password"
android:id="@+id/txtpassword"
android:textColor="@color/colorAccent"
android:textColorHint="@color/colorAccent"
android:focusable="true"
android:inputType="textPassword"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/kesempatan_anda_3x"
android:textSize="17sp"
android:id="@+id/logincount"
/>
<Button
android:id="@+id/btnlogin"
android:layout_width="350dp"
android:layout_height="wrap_content"
android:layout_marginTop="0dp"
android:text="@string/login" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/btnMhs"
android:text="@string/profil"/>
</LinearLayout>
</android.support.constraint.ConstraintLayout>
my build
<pre> apply plugin: 'com.android.application'
android {
compileSdkVersion 28
buildToolsVersion '28.0.3'
defaultConfig {
applicationId "com.example.ndarecuy.myapp"
minSdkVersion 16
targetSdkVersion 28
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.android.support:appcompat-v7:28.0.0'
implementation 'com.android.support.constraint:constraint-layout:1.1.3'
implementation 'com.android.support:design:28.0.0'
implementation 'com.android.support:support-v4:28.0.0'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}
我被困在这里..任何建议/帮助都会非常感谢..
最佳答案
您的 MainActivity Java 类返回 xml 值
setContentView(R.layout.activity_main)
但是你的 xml 被命名为
activitymain.xml
关于java-android error.cannot.find.symbol.variable，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/53365789/