Android進度條、自動提示框、下拉框動態資料載入
阿新 • • 發佈：2018-12-10
1.進度條實現
佈局檔案:
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity"> <FrameLayout android:layout_width="match_parent" android:layout_height="60dp"> <TextView android:id="@+id/text1" android:layout_width="60dp" android:layout_height="match_parent" /> <ProgressBar android:id="@+id/pb" android:layout_width="match_parent" style="?android:attr/progressBarStyleHorizontal" android:layout_height="60dp" android:max="100" /> </FrameLayout> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="載入" android:onClick="setProgress"/> </LinearLayout>
style="?android:attr/progressBarStyleHorizontal" 設定進度條的樣式,不設定預設為橢圓狀的進度條
實現:
package com.study.t212_05; import android.os.Handler; import android.os.Message; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.ProgressBar; import android.widget.TextView; import android.widget.Toast; public class MainActivity extends AppCompatActivity { private ProgressBar pb;//進度條 private int progressBar;//進度值 private TextView tv;//顯示進度值的文字框 private int code = 1; private MyHandler mh = new MyHandler();//非同步處理UI元件 private class MyHandler extends Handler{ @Override public void handleMessage(Message msg) { super.handleMessage(msg); if (code == msg.what){ progressBar++; pb.setProgress(progressBar); tv.setText(progressBar + "%"); } } } public void setProgressBar(int progressBar) { this.progressBar = progressBar; } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); pb = findViewById(R.id.pb); tv = findViewById(R.id.text1); } //進度條 public void setProgress(View view) { if (progressBar == 0){ new MyThread().start(); } } //子執行緒 private class MyThread extends Thread{ @Override public void run() { super.run(); while (true) { try { Thread.sleep(100);//0.1秒延遲 注:該耗時操作不能放在主執行緒中!!! } catch (Exception e) { e.printStackTrace(); } if (progressBar == 100) {//進度滿100時,要清0 progressBar = 0; break; } Message mg = new Message(); mg.what = 1; mh.sendMessage(mg);//因為子執行緒無法操控UI元件(進度條元件除外),所以將任務交由Handler進行非同步處理 } } } }
效果圖:點選載入按鈕,進度條就會載入
執行緒注意事項： 不能在主執行緒中執行耗時的操作，只能在子執行緒中操作 另外，在子執行緒中不能操作主執行緒中的控制元件(ProgressBar除外)
2.自動提示框
佈局檔案:
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity"> <AutoCompleteTextView android:id="@+id/alert" android:layout_width="match_parent" android:layout_height="60dp" /> </LinearLayout>
實體類：
package com.study.t212_06;
public class Book {
private Integer id;
private String name;
private Integer image;
public Book() {
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getImage() {
return image;
}
public void setImage(Integer image) {
this.image = image;
}
}
資料準備:
package com.study.t212_06;
import java.util.ArrayList;
import java.util.List;
public class BookDAO {
public List<Book> list() {
List<Book> bookList = new ArrayList<Book>();
String[] names = {"憤怒的小鳥", "湯姆貓", "落湯雞", "牛牛", "哈巴狗", "神龍", "烤鴨",
"小象", "美人魚", "九尾狐"};
int[] images = {R.drawable.bird, R.drawable.cat, R.drawable.chicken,
R.drawable.cow, R.drawable.dog, R.drawable.dragon,
R.drawable.duck, R.drawable.elephant, R.drawable.fish,
R.drawable.fox};
Book b = null;
for (int i = 0; i < names.length; i++) {
b = new Book();
b.setId(i + 1);
b.setName(names[i]);
b.setImage(images[i]);
bookList.add(b);
}
return bookList;
}
}展示資料的佈局檔案:
<?xml version="1.0" encoding="utf-8"?>
<TextView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_height="match_parent"
android:layout_width="match_parent"
android:textColor="@color/red">
</TextView>實現:
package com.study.t212_06;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;
import android.widget.MultiAutoCompleteTextView;
import android.widget.SimpleAdapter;
import android.widget.Spinner;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class MainActivity extends AppCompatActivity {
private String[] data1;
private ArrayAdapter<String> adapter1;
private AutoCompleteTextView act;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
act = findViewById(R.id.alert);
//1.準備資料
data1 = new String[]{ "憤怒的小鳥", "湯姆貓", "落湯雞", "牛牛", "哈巴狗", "神龍", "烤鴨", "小象", "美人魚", "九尾狐" };
//2.建立介面卡
adapter1 = new ArrayAdapter<String>(this,R.layout.adapter_text1,data1);
//3.繫結介面卡
act.setAdapter(adapter1);
}
}效果圖:自動提示框中輸入'憤怒',會顯示憤怒的小鳥
注:自動提示框使用的是陣列介面卡,通過介面卡將資料繫結到要顯示的佈局檔案中,最後為自動提示框設定介面卡
3.帶圖示的下拉框
佈局檔案:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<Spinner
android:id="@+id/sp_2"
android:layout_width="match_parent"
android:layout_height="wrap_content"></Spinner>
</LinearLayout>資料採用的與上個案例一樣,如果不記得了,可以往上翻一翻
上一個案例的資料是有圖片資源的
注:這裡有一點需要注意,存放圖片時必須存放到這個檔案中,如下圖,否則資料載入時將無法訪問到對應的圖片資源
展示資料的佈局檔案:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
android:layout_height="60dp"
>
<!--圖示-->
<ImageView
android:id="@+id/iv1"
android:layout_width="60dp"
android:layout_height="match_parent" />
<!--下拉選項-->
<TextView
android:id="@+id/tv1"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>實現:
package com.study.t212_06;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;
import android.widget.MultiAutoCompleteTextView;
import android.widget.SimpleAdapter;
import android.widget.Spinner;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class MainActivity extends AppCompatActivity {
//圖片下拉框
private List<Map<String,Object>> data3;
private SimpleAdapter adapter3;//簡易介面卡
private Spinner sp1;//下拉框元件
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
sp1 = findViewById(R.id.sp_2);
//1.資料準備
data3 = loadData3();
//2.建立簡易介面卡
adapter3 = new SimpleAdapter(this,data3,R.layout.adapter_text2,new String[]{"name","image"},new int[]{R.id.tv1,R.id.iv1});
//3.為下拉框繫結介面卡
sp1.setAdapter(adapter3);
}
private List<Map<String,Object>> loadData3() {
List<Book> list = new BookDAO().list();
List<Map<String,Object>> mapList = new ArrayList<Map<String, Object>>();
Map<String,Object> map = null;
for (Book book : list) {
map = new HashMap<>();
map.put("name",book.getName());
map.put("image",book.getImage());
mapList.add(map);
}
return mapList;
}
}效果圖:
