我想创建一个具有以下布局的小部件:
<LinearLayout orientation="horizontal">
<CheckBox />
<EditText />
<SeekBar />
</LinearLayout>
当搜索栏移动时,应检查复选框并使用当前搜索条值更新编辑框。
我在应用程序中反复使用类似的东西,并厌倦了重新实现同样的事情。
将所有这些封装到自己的类中以便重用的最佳方法是什么?
public class SeekChoice extends LinearLayout {
public SeekChoice(Context context) {
super(context);
LayoutInflater inflater = (LayoutInflater) context.getSystemService( Context.LAYOUT_INFLATER_SERVICE );
LinearLayout ll = (LinearLayout) inflater.inflate(R.id.widget_item, null);
this.addView(ll);
}
}
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="fill_parent"
android:orientation="horizontal"
android:id="@+id/widget_item"
>
<CheckBox
android:id="@+id/checkBox_item_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Item Name" />
<EditText
android:id="@+id/editText_item_count"
android:layout_width="82dp"
android:layout_height="wrap_content"
android:enabled="false"
android:ems="10" >
</EditText>
<SeekBar
android:id="@+id/seekBar_item_count"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1" />
</LinearLayout>
然后在我的布局中我说:
<com.example.lobsternav.widget.SeekChoice
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
例外情况如下:
09-09 20:23:08.759: E/AndroidRuntime(21888): FATAL EXCEPTION: main
09-09 20:23:08.759: E/AndroidRuntime(21888): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.lobsternav/com.example.lobsternav.MarkActivity}: android.view.InflateException: Binary XML file line #344: Error inflating class com.example.lobsternav.widget.SeekChoice
09-09 20:23:08.759: E/AndroidRuntime(21888): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
09-09 20:23:08.759: E/AndroidRuntime(21888): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
09-09 20:23:08.759: E/AndroidRuntime(21888): at android.app.ActivityThread.access$600(ActivityThread.java:130)
09-09 20:23:08.759: E/AndroidRuntime(21888): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
09-09 20:23:08.759: E/AndroidRuntime(21888): at android.os.Handler.dispatchMessage(Handler.java:99)
09-09 20:23:08.759: E/AndroidRuntime(21888): at android.os.Looper.loop(Looper.java:137)
09-09 20:23:08.759: E/AndroidRuntime(21888): at android.app.ActivityThread.main(ActivityThread.java:4745)
09-09 20:23:08.759: E/AndroidRuntime(21888): at java.lang.reflect.Method.invokeNative(Native Method)
09-09 20:23:08.759: E/AndroidRuntime(21888): at java.lang.reflect.Method.invoke(Method.java:511)
09-09 20:23:08.759: E/AndroidRuntime(21888): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
09-09 20:23:08.759: E/AndroidRuntime(21888): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
09-09 20:23:08.759: E/AndroidRuntime(21888): at dalvik.system.NativeStart.main(Native Method)
09-09 20:23:08.759: E/AndroidRuntime(21888): Caused by: android.view.InflateException: Binary XML file line #344: Error inflating class com.example.lobsternav.widget.SeekChoice
09-09 20:23:08.759: E/AndroidRuntime(21888): at android.view.LayoutInflater.createView(LayoutInflater.java:596)
09-09 20:23:08.759: E/AndroidRuntime(21888): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:687)
09-09 20:23:08.759: E/AndroidRuntime(21888): at android.view.LayoutInflater.rInflate(LayoutInflater.java:746)
09-09 20:23:08.759: E/AndroidRuntime(21888): at android.view.LayoutInflater.rInflate(LayoutInflater.java:749)
09-09 20:23:08.759: E/AndroidRuntime(21888): at android.view.LayoutInflater.rInflate(LayoutInflater.java:749)
09-09 20:23:08.759: E/AndroidRuntime(21888): at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
09-09 20:23:08.759: E/AndroidRuntime(21888): at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
09-09 20:23:08.759: E/AndroidRuntime(21888): at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
09-09 20:23:08.759: E/AndroidRuntime(21888): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:256)
09-09 20:23:08.759: E/AndroidRuntime(21888): at android.app.Activity.setContentView(Activity.java:1867)
09-09 20:23:08.759: E/AndroidRuntime(21888): at com.example.lobsternav.MarkActivity.onCreate(MarkActivity.java:85)
09-09 20:23:08.759: E/AndroidRuntime(21888): at android.app.Activity.performCreate(Activity.java:5008)
09-09 20:23:08.759: E/AndroidRuntime(21888): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
09-09 20:23:08.759: E/AndroidRuntime(21888): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
09-09 20:23:08.759: E/AndroidRuntime(21888): ... 11 more
09-09 20:23:08.759: E/AndroidRuntime(21888): Caused by: java.lang.NoSuchMethodException: <init> [class android.content.Context, interface android.util.AttributeSet]
09-09 20:23:08.759: E/AndroidRuntime(21888): at java.lang.Class.getConstructorOrMethod(Class.java:460)
09-09 20:23:08.759: E/AndroidRuntime(21888): at java.lang.Class.getConstructor(Class.java:431)
09-09 20:23:08.759: E/AndroidRuntime(21888): at android.view.LayoutInflater.createView(LayoutInflater.java:561)
09-09 20:23:08.759: E/AndroidRuntime(21888): ... 24 more
疯狂......如果我没有定义以下构造函数,它会引发异常:
public SeekChoice(Context context, AttributeSet attrs) {
super(context, attrs);
}
我猜需要定义LinearLayout的所有构造函数并需要调用超级构造函数?
答案 0 :(得分:3)
最后有这个工作。
我的Java代码:
package com.example.lobsternav.widget;
import java.util.ArrayList;
import java.util.List;
import com.example.lobsternav.R;
import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.SeekBar;
import android.widget.RelativeLayout.LayoutParams;
import android.widget.SeekBar.OnSeekBarChangeListener;
public class SeekChoice extends LinearLayout implements OnSeekBarChangeListener, OnCheckedChangeListener{
CheckBox checkbox = null;
EditText editBox =null;
SeekBar seekbar = null;
boolean isChecked = false;
int curValue = 0;
List <String> mappings = new ArrayList<String>();
int startRange = 0;
int endRange = 50;
int defaultValue = 0;
private void init(Context context)
{
this.setOrientation(LinearLayout.HORIZONTAL);
LayoutInflater inflater = (LayoutInflater) context.getSystemService( Context.LAYOUT_INFLATER_SERVICE );
LinearLayout layout = (LinearLayout)inflater.inflate(R.layout.item_widget, null);
layout.setOrientation(LinearLayout.HORIZONTAL);
layout.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,LinearLayout.LayoutParams.WRAP_CONTENT));
checkbox = (CheckBox)layout.findViewById(R.id.checkBox_item_name);
checkbox.setOnCheckedChangeListener(this);
//this.addView(checkbox);
editBox = (EditText)layout.findViewById(R.id.editText_item_count);
editBox.setEnabled(false);
editBox.setText(getMappedValue(defaultValue));
int ems = (new Integer(endRange)).toString().length()+1;
editBox.setEms(ems);
//this.addView(editBox);
seekbar = (SeekBar)layout.findViewById(R.id.seekBar_item_count);
seekbar.setMax(endRange);
seekbar.setProgress(defaultValue);
//seekbar.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,LinearLayout.LayoutParams.WRAP_CONTENT));
seekbar.setOnSeekBarChangeListener(this);
//this.addView(seekbar);
this.addView(layout);
}
public void readAttributes(Context context, AttributeSet attrs)
{
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.SeekChoice);
this.startRange = a.getInteger(R.styleable.SeekChoice_startRange, 0);
this.endRange = a.getInteger(R.styleable.SeekChoice_endRange, 100);
this.defaultValue = a.getInteger(R.styleable.SeekChoice_defaultValue, 0);
this.isChecked = a.getBoolean(R.styleable.SeekChoice_isChecked, false);
a.recycle();
}
public SeekChoice(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
readAttributes( context, attrs);
init(context);
}
public SeekChoice(Context context, AttributeSet attrs) {
super(context, attrs);
readAttributes( context, attrs);
init(context);
}
public SeekChoice(Context context) {
super(context);
init(context);
}
public SeekChoice(Context context,int startRange, int endRange, int defaultValue) {
super(context);
init(context);
}
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser)
{
this.editBox.setText("" + getMappedValue(progress));
if (progress > 0)
{
this.checkbox.setChecked(true);
isChecked = true;
}
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
// TODO Auto-generated method stub
}
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
// TODO Auto-generated method stub
}
public int getStartRange() {
return startRange;
}
public void setStartRange(int startRange) {
this.startRange = startRange;
}
public int getEndRange() {
return endRange;
}
public void setEndRange(int endRange) {
this.endRange = endRange;
}
public int getDefaultValue() {
return defaultValue;
}
public void setDefaultValue(int defaultValue) {
this.defaultValue = defaultValue;
}
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked)
{
this.isChecked = isChecked;
if (isChecked == false)
{
this.seekbar.setProgress(0);
}
this.editBox.setText("" + getMappedValue(0));
}
public String getMappedValue(int current)
{
if (current < this.getMappings().size())
{
return this.getMappings().get(current);
}
return "" + current;
}
public List<String> getMappings() {
return mappings;
}
public void setMappings(List<String> mappings) {
this.mappings = mappings;
}
public void addMappings(String mapping) {
this.mappings.add(mapping);
}
public boolean isChecked() {
return isChecked;
}
public String getCurrentValue()
{
return this.editBox.getText().toString();
}
public void setChecked(boolean isChecked) {
this.isChecked = isChecked;
}
}
我在构造函数中膨胀的布局:
<?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="wrap_content"
android:orientation="vertical"
android:id="@layout/item_widget">
<CheckBox
android:id="@+id/checkBox_item_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Item Name" />
<EditText
android:id="@+id/editText_item_count"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:enabled="false"
android:ems="10" >
</EditText>
<SeekBar
android:id="@+id/seekBar_item_count"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1" />
</LinearLayout>
/res/values/attr.xml(用于将自定义属性传递给窗口小部件):
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="SeekChoice">
<attr name="startRange" format="integer"/>
<attr name="endRange" format="integer"/>
<attr name="defaultValue" format="integer"/>
<attr name="isChecked" format="boolean"/>
</declare-styleable>
</resources>
我包含小部件的布局文件:
<RelativeLayout android:layout_width="fill_parent"
android:layout_height="match_parent"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:custom="http://schemas.android.com/apk/res/com.example.lobsternav">
.....
.....
<com.example.lobsternav.widget.SeekChoice
android:layout_width="match_parent"
android:layout_height="wrap_content"
custom:defaultValue="10"
/>
.....
.....
</RelativeLayout>
浪费我的时间的事情,所以与大家分享:
1)。确保添加要覆盖的类的所有构造函数
2)。命名空间(在我的示例中是“xmlns:custom =”http://schemas.android.com/apk/res/com.example.lobsternav“)必须是您的R所在的包名称,而不是包含小部件驻留。
3)。在attr.xml文件中,标签declare-styleable在eclipse xml编辑器中不会自动完成,因此它看起来不像有效标签 - 但它确实如此。我读了2篇其他帖子说要使用这个但是android eclipse插件并没有将它显示为资源下的有效标签,所以我几乎没有尝试使用标签。
答案 1 :(得分:0)
选项#1:不要将其打包到自定义小部件中,而是打包成片段。
选项#2:创建LinearLayout
的子类,将其方向设置为水平,并将布局文件扩展为包含上述内容的文件,并使用merge
标记替换LinearLayout
(或者直接在Java代码中添加子代,如果您愿意,并且不需要布局级自定义性。然后LinearLayout
可以将其子节点中的事件侦听器连接起来。