Question

我第二次尝试教程并得到了我无法解决的相同错误。我在MainActivityTextview上得到红色下划线。我分配了一个文本框，其ID为“MainActivityTextview”，现在我试图将文本设置为它。简单吧？但是我无法让它发挥作用。我错过了一个导入？感谢

MainActivity.java

package com.Proteintracker;

import android.app.Activity;  
import android.os.Bundle;
import android.view.Menu;
import android.widget.TextView;

public class MainActivity extends Activity {

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    TextView textView = (TextView) findViewById(android.R.id.MainActivityTextview);
    textView.setText("hello world");
}


}

r.java

package com.Proteintracker;

public final class R {
public static final class attr {
}
public static final class drawable {
    public static final int ic_action_search=0x7f020000;
    public static final int ic_launcher=0x7f020001;
}
public static final class id {
    public static final int MainActivityTextview=0x7f070000;
    public static final int menu_settings=0x7f070001;
}
public static final class layout {
    public static final int activity_main=0x7f030000;
}
public static final class menu {
    public static final int activity_main=0x7f060000;
}
public static final class string {
    public static final int app_name=0x7f040000;
    public static final int hello_world=0x7f040001;
    public static final int menu_settings=0x7f040002;
    public static final int title_activity_main=0x7f040003;
}
public static final class style {
    public static final int AppTheme=0x7f050000;
}
}

activity_main.xml中

<RelativeLayout 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" >

<TextView
    android:id="@+id/MainActivityTextview"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:layout_centerVertical="true"
    android:text="@string/hello_world"
    tools:context=".MainActivity" />

</RelativeLayout>

Answer 1

使用

TextView textView = (TextView) findViewById(R.id.MainActivityTextview);

而不是

TextView textView = (TextView) findViewById(android.R.id.MainActivityTextview);

更改这些行之后，您必须从Eclipse IDE上的Option菜单中的Project->Clean刷新并清理项目

Answer 2

TextView textView = (TextView) findViewById(R.id.MainActivityTextview);

删除“android。”，它是你的资源，而不是系统。

更新android中的文本视图

2 个答案: