感谢P.T.为在Eclipse中构建多SDK Android应用程序而不失去编译时检查问题提供了正确的答案。然而,当我尝试像推荐的那样使用@TargetApi()注释时,它会生成语法错误。
@TargetApi(11) // location 1
public class DisplayMessageActivity extends Activity {
@Override
@TargetApi(11) // location 2
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
@TargetApi(11) // location 3
getActionBar().setDisplayHomeAsUpEnabled(true); }
当@TargetApi行位于代码中间时,会生成两个语法错误,如位置3所示:
x Syntax error, insert "enum Identifier" to complete EnumHeaderName
x Syntax error, insert "enumBody" to complete BlockStatements
无论我将
@TargetApi
行放在if
语句前还是后,错误都存在。除了Lint API Check
文章http://tools.android.com/recent/lintapicheck中提到的内容之外,是否还有其他先决条件(导入)或其他考虑因素可以使@TargetApi()正常工作?--- 编辑 9/3/2012 ---
如果我将@TargetApi注释移到类定义之前(显示为位置1)或方法定义之前(显示为位置2,即在@Override注释之前或之后),我会得到不同的错误:
x TargetApi cannot be resolved to a type
x The attribute value is undefined for the annotation type TargetApi
--- 编辑 2012年9月4日 ---
以下是完整的源代码:
package com.example.my.first.app;
import android.app.Activity;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.support.v4.app.NavUtils;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
public class DisplayMessageActivity extends Activity {
@TargetApi(11)
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// ActionBar introduced in Android 3.0 Honeycomb API 11
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
getActionBar().setDisplayHomeAsUpEnabled(true); } // Up Navigation
// Get the message from the intent
Intent intent = getIntent();
String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
// Create the text view
TextView textView = new TextView(this);
textView.setTextSize(40);
textView.setText(message);
// Set the text view as the activity layout
setContentView(textView);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_display_message, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
NavUtils.navigateUpFromSameTask(this);
return true;
}
return super.onOptionsItemSelected(item);
}
}