java - 找不到 ID 0x7f070053 的 View

Question

正在 Android Studio 中测试一些东西并遇到了这个错误:

FATAL EXCEPTION: main Process: com.meisolsson.app, PID: 25610 java.lang.RuntimeException: Unable to start activity ComponentInfo{com.meisolsson.app/com.meisolsson.app.LoginActivity}: java.lang.IllegalArgumentException: No view found for id 0x7f070053 (com.meisolsson.app:id/container) for fragment PlaceholderFragment{4284e750 #0 id=0x7f070053}

这是我的 LoginActivity.java

package com.meisolsson.app;

import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.os.Build;
import android.view.Window;
import android.widget.Button;

public class LoginActivity extends ActionBarActivity {

private Button loginButton;



@Override
protected void onCreate(Bundle savedInstanceState) {
    this.requestWindowFeature(Window.FEATURE_NO_TITLE);
    super.onCreate(savedInstanceState);
    setContentView(R.layout.fragment_login);

    if (savedInstanceState == null) {
        getSupportFragmentManager().beginTransaction()
                .add(R.id.container, new PlaceholderFragment())
                .commit();
    }
    this.setContentView(R.layout.fragment_login);
    this.loginButton = (Button)this.findViewById(R.id.button);
    this.loginButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            finish();
        }
    });
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {

    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.login, 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
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

public static class PlaceholderFragment extends Fragment {

    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_login, container, false);
        return rootView;

       }
   }
}

还有我的 fragment_login.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context=".LoginActivity$PlaceholderFragment"
android:focusable="true"
android:background="#fcff00">
<EditText
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/editText"
    android:hint="@string/user"
    android:padding="10dp"
    android:background="#ffffff"
    android:layout_above="@+id/editText2"
    android:layout_alignLeft="@+id/editText2"
    android:layout_alignRight="@+id/editText2" />

<EditText
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:inputType="textPassword"
    android:ems="10"
    android:id="@+id/editText2"
    android:layout_centerVertical="true"
    android:layout_centerHorizontal="true"
    android:hint="@string/pass"
    android:background="#ffffff"
    android:padding="10dp" />


<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/login"
    android:id="@+id/button"
    style="@style/AppTheme"
    android:background="#ff5900"
    android:shadowColor="#000000"
    android:layout_below="@+id/editText2"
    android:layout_alignLeft="@+id/editText"
    android:layout_alignRight="@+id/editText2"
    android:clickable="true"/>

</RelativeLayout>

Answer 1

问题在于您执行此操作的方式。对于 Activity，您没有设置 Fragment 的 View ，您设置了一个单独的 View ，它有一个地方可以放置一个 > fragment 。根据您执行 PlaceHolderFragment 的方式，以下内容应该会得到一个正常运行的应用程序。

首先添加这个文件:

activity_main.xml

<FrameLayout
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>

然后在您的 Activity 中更改这些内容:

登录 Activity .java

/* Same stuff*/@Overrideprotected void onCreate(Bundle savedInstanceState) {    this.requestWindowFeature(Window.FEATURE_NO_TITLE);    super.onCreate(savedInstanceState);    //This is the important change right here!    setContentView(R.layout.activity_main);    if (savedInstanceState == null) {        getSupportFragmentManager().beginTransaction()                .add(R.id.container, new PlaceholderFragment())                .commit();    }    //The stuff that you had handling buttons should go in your    //PlaceHolderFragment class's onCreateView() method}

希望对您有所帮助。祝你好运!