[英]Android App doesn't respond when clicking on the back-arrow button
各位開發者您好。 我開發了一個 Android 應用程序,它使用 Flickr API 來根據用戶請求顯示任何圖像。 我是開發的最后一步,一切看起來都很棒。 除非您單擊任何圖像以將其展開詳細視圖以及單擊返回箭頭以返回 go 時 - 不響應..:任何幫助將不勝感激:)
查看照片詳情。java:
package com.example.flickrbrowser;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ImageView;
import android.widget.TextView;
import com.squareup.picasso.Picasso;
import androidx.annotation.RequiresApi;
public class ViewPhotoDetailsActivity extends BaseActivity {
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.photo_details);
activateToolbarWithHomeEnabled();
Intent intent = getIntent();
Photo photo = (Photo) intent.getSerializableExtra(PHOTO_TRANSFER);
TextView photoTitle = (TextView) findViewById(R.id.photo_title);
photoTitle.setText("Title: " + photo.getTitle());
TextView photoTags = (TextView) findViewById(R.id.photo_tags);
photoTags.setText("Tags: " + photo.getTags());
TextView photoAuthor = (TextView) findViewById(R.id.photo_author);
photoAuthor.setText(photo.getAuthor());
ImageView photoImage = (ImageView) findViewById(R.id.photo_image);
Picasso.with(this).load(photo.getLink())
.error(R.drawable.placeholder)
.placeholder(R.drawable.placeholder)
.into(photoImage);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu_photo_details, menu);
return true;
}
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return false;
}
}
photo_details.xml:
<?xml version="1.0" encoding="utf-8"?>
<ScrollView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:flickr="http://schemas.android.com/apk/res-auto"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="com.example.flickrbrowser.ViewPhotoDetailsActivity"
tools:showIn="@layout/photo_details">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<include
android:id="@+id/app_bar"
layout="@layout/toolbar"
android:layout_width="match_parent"
android:layout_height="?actionBarSize" />
<androidx.cardview.widget.CardView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="16dp"
android:layout_marginRight="16dp"
android:layout_marginTop="16dp"
flickr:cardBackgroundColor="?colorPrimary"
flickr:cardCornerRadius="8dp"
flickr:cardPreventCornerOverlap="false"
flickr:contentPaddingTop="16dp"
flickr:contentPaddingBottom="16dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="@+id/photo_image"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginBottom="8dp"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginTop="8dp"
android:scaleType="centerCrop"
android:src="@drawable/placeholder" />
<TextView
android:id="@+id/photo_author"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="top|center"
android:paddingTop="8dp"
android:textColor="@color/flickrSecondaryTextColor"
android:textSize="14sp" />
</FrameLayout>
<TextView
android:id="@+id/photo_title"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginTop="8dp"
android:textColor="@color/flickrPrimaryTextColor"
android:textSize="14sp" />
<TextView
android:id="@+id/photo_tags"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginTop="8dp"
android:textColor="@color/flickrPrimaryTextColor"
android:textSize="10sp" />
</LinearLayout>
</androidx.cardview.widget.CardView>
</LinearLayout>
</ScrollView>
后退按鈕的 id 為: android.R.id.home
。 所以你可以把它當作
if (item?.itemId == android.R.id.home) {
finish()
}
或者只是修改你的
override fun onOptionsItemSelected(item: MenuItem?): Boolean {
if (item.itemId == R.id.action_settings) {
// TODO - handle 'settings' click
}
return super.onOptionsItemSelected(item)
}
而不是只返回true/false
,所以主頁按鈕將由super
方法處理。
正如@Boken 所說,后退(也稱為“向上”)按鈕是一個菜單按鈕,其 ID android.R.id.home
所以當點擊該按鈕時,您可以像這樣處理點擊:
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle item selection
switch (item.getItemId()) {
//You can also use if-else statements instead of switch (switch is a better option)
case R.id.action_settings:
return true;
case android.R.id.home: //when the back button is clicked
// handle this action here
return true;
default:
return super.onOptionsItemSelected(item);
}
}
如果你想返回上一個屏幕,你可以使用onBackPressed()
像這樣:
case android.R.id.home: //when the back button is clicked
onBackPressed();
return true;
(更直接的回答)沒有檢查那個菜單項。 必須將 onOptionsItemSelected(在 ViewPhotoDetailsActivity.java 中)更改為
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
} else if (id == android.R.id.home) {
finish();
}
return false;
}
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