“程序包android.support.v7.app不存在” androidStudio中的错误 [英] "package android.support.v7.app does not exist" error in androidStudio
问题描述
我只是开始使用androidStudio
i进行android开发,这是在udacity教程之后,他们要求我们复制粘贴一些代码并运行它。
i在粘贴
i后无法运行鳕鱼。主要问题是在导入
i am just starting with android development using androidStudio i am following udacity tutorial where they asked us to copy paste some code and run it i am unable to run the cod after pasting i think the major problem is while importing
import android.support.v7.app.AppCompatActivity;
我已经检查了互联网以解决此问题,包括stackoverflow
,但似乎每种情况下bb $ bi都试图导入
import androidx.appcompat.app.AppcompatActivity;
而不是
import android.support.v7.app.AppCompatActivity;
,但是它没有使用androidStudio版本3.4来充实
i。
i have checked internet for solution to this problem including stackoverflow
but it seems that it is different for each case
i have tried to import
import androidx.appcompat.app.AppcompatActivity;
instead of
import android.support.v7.app.AppCompatActivity;
but it didn't hepled
i am using androidStudio version 3.4
主要活动:
package com.example.android.justjava;
/**
* IMPORTANT: Make sure you are using the correct package name.
* This example uses the package name:
* package com.example.android.justjava
* If you get an error when copying this code into Android studio, update it to match teh package name found
* in the project's AndroidManifest.xml file.
**/
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.TextView;
/**
* This app displays an order form to order coffee.
*/
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
/**
* This method is called when the order button is clicked.
*/
public void submitOrder(View view) {
display(1);
}
/**
* This method displays the given quantity value on the screen.
*/
private void display(int number) {
TextView quantityTextView = (TextView) findViewById(R.id.quantity_text_view);
quantityTextView.setText("" + number);
}
}
module.App(build gradle):
module.App(build gradle):
apply plugin: 'com.android.application'
android {
compileSdkVersion 29
buildToolsVersion "29.0.1"
defaultConfig {
applicationId "com.example.android.justjava"
minSdkVersion 15
targetSdkVersion 29
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'androidx.appcompat:appcompat:1.0.2'
implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'androidx.test:runner:1.2.0'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
}
error: cannot find symbol class AppcompatActivity
error: cannot find symbol class AppCompatActivity
error: method does not override or implement a method from a supertype
error: cannot find symbol variable super
error: cannot find symbol method setContentView(int)
error: cannot find symbol method findViewById(int)
推荐答案
您正在使用 androidx 库。
implementation 'androidx.appcompat:appcompat:1.0.2'
然后您不能使用导入支持库类。
这是e 正确的课程:
import androidx.appcompat.app.AppCompatActivity;
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