r.java文件在android的作用,在android中的R文件

为什么在android studio中不生成R文件？ xml文件中没有任何错误 . 当我构建项目时，它会给出如下错误消息 .

错误：(2)检索项目的父项时出错：找不到与给定名称“android：TextAppearance.Material.Widget.Button.Inverse”匹配的资源 . 错误：(2)检索项目的父项时出错：找不到与给定名称“android：Widget.Material.Button.Colored”匹配的资源 . 错误：任务'：app：processDebugResources'的执行失败 . com.android.ide.common.process.ProcessException：org.gradle.process.internal.ExecException：处理'命令'C：\ Users \ admin_2 \ AppData \ Local \ Android \ Sdk \ build-tools \ 22.0.1 \ aapt .exe''以非零退出值1结束

代码

public class MainActivity extends Activity {

int counter;

Button add,sub;

TextView display;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

counter = 0;

add = (Button)findViewById(R.id.bAdd);

sub = (Button)findViewById(R.id.bSub);

display = (TextView)findViewById(R.id.TvDisplay);

add.setOnClickListener(new View.OnClickListener() {

public void onClick(View v) {

counter++;

display.setText("Your total is" + counter);

}

});

sub.setOnClickListener(new View.OnClickListener() {

public void onClick(View v) {

counter--;

display.setText("Your total is" + counter);

}

});

}

@Override

public boolean onCreateOptionsMenu(Menu menu) {

// Inflate the menu; this adds items to the action bar if it is present.

getMenuInflater().inflate(R.menu.menu_main, menu);

return true;

}

@Override

public boolean onOptionsItemSelected(MenuItem item) {

// Handle action bar item clicks here. The action bar will

// automatically handle clicks on the Home/Up button, so long

int id = item.getItemId();

if (id == R.id.action_settings) {

return true;

}

return super.onOptionsItemSelected(item);

}

}

查看布局

xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

android:orientation="vertical"

>

android:layout_height="wrap_content"

android:layout_width="396dp"

android:text="your total is 0"

android:textSize="80px"

android:layout_gravity="center_horizontal"

android:gravity="center"

android:id="@+id/TvDisplay"/>

android:layout_height="wrap_content"

android:text="add_one"

android:textSize="20dp"

android:layout_gravity="center_vertical"

android:gravity="center"

android:id="@+id/bAdd"

/>

android:layout_height="wrap_content"

android:text="subtract_one"

android:textSize="20dp"

android:gravity="center"

android:id="@+id/bSub"

/>

清单文件

package="com.example.admin_2.myapplication" >

android:allowBackup="true"

android:icon="@mipmap/ic_launcher"

android:label="@string/app_name"

android:theme="@style/AppTheme" >

android:name=".MainActivity"

android:label="@string/app_name" >