java 无法在 Android Studio 中解析符号 fab
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Cannot resolve symbol fab in Android Studio
提问by Ryan Scollard
I am developing an app but I am having an issue with a piece of code. The same piece of code is giving me the same error for a few different pages.
我正在开发一个应用程序，但我遇到了一段代码的问题。同一段代码在几个不同的页面上给了我同样的错误。
The code is as follows:
代码如下：
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
buttonSignIn = (Button) findViewById(R.id.buttonSignIN);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG).setAction("Action", null).show();
buttonSignIn.setOnClickListener(this);
}
});
}}
It gives me an error on the line below saying it cannot resolve symbol fab
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
它在下面的行中给我一个错误，说它无法解析符号 fab
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
回答by Ravers
You probably deleted the fab in your activity_main:
你可能在你的activity_main中删除了fab：
If that's the case, and you really don't need the fab, you probably just need to delete this piece of code:
如果是这种情况，并且您真的不需要 fab，您可能只需要删除这段代码：
buttonSignIn = (Button) findViewById(R.id.buttonSignIN);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG).setAction("Action", null).show();
buttonSignIn.setOnClickListener(this);
}
});
回答by Ridha Rezzag
add the support:design in build.gradle: module app to dependencies this will fix it
将 build.gradle:module app 中的 support:design 添加到依赖项中，这将修复它
compile 'com.android.support:design:26.+'
will look like this :
看起来像这样：
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
exclude group: 'com.android.support', module: 'support-annotations'
})
compile 'com.android.support:appcompat-v7:26.+'
compile 'com.android.support.constraint:constraint-layout:1.0.2'
compile 'com.android.support:design:26.+'
testCompile 'junit:junit:4.12'
}
}
