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控件自定义属性介绍 http://www.jb51.net/article/32172.htm

2014-11-05 09:58 295 查看
自定义控件在android中无处不见,自定义控件给了我们很大的方便。比如说,一个视图为imageview ,imagebutton ,textview
等诸多控件的组合,用的地方有很多,我们不可能每次都来写3个的组合,既浪费时间,效率又低。在这种情况下,我们就可以自定义一个view来替换他们,不仅提升了效率并且在xml中运用也是相当的美观。

一、控件自定义属性介绍
以下示例中代码均在values/attrs.xml 中定义,属性均可随意命名。

1. reference:参考某一资源ID。
示例:
[java]

复制代码 代码如下:

<declare-styleable name = "名称">

<attr name = "background" format = "reference" />
<attr name =
"src" format = "reference" />
</declare-styleable>

2.
color:颜色值。
示例:
[java]

复制代码 代码如下:

<declare-styleable name = "名称">

<attr name = "textColor" format = "color" />

</declare-styleable>

3. boolean:布尔值。
示例:
[java]

复制代码 代码如下:

<declare-styleable name = "名称">

<attr name = "focusable" format = "boolean" />

</declare-styleable>

4. dimension:尺寸值。
示例:

[java]

复制代码 代码如下:

<declare-styleable name = "名称">

<attr name = "layout_width" format = "dimension" />

</declare-styleable>

5. float:浮点值。
示例:
[java]

复制代码 代码如下:

<declare-styleable name = "名称">

<attr name = "fromAlpha" format = "float" />
<attr name =
"toAlpha" format = "float" />
</declare-styleable>

6.
integer:整型值。
示例:
[java]

复制代码 代码如下:

<declare-styleable name = "名称">

<attr name = "frameDuration" format="integer" />
<attr name =
"framesCount" format="integer" />
</declare-styleable>

7. string:字符串。
示例:
[java]

复制代码 代码如下:

<declare-styleable name = "名称">

<attr name = "text" format = "string" />

</declare-styleable>

8. fraction:百分数。
示例:
[java]

复制代码 代码如下:

<declare-styleable name="名称">

<attr name = "pivotX" format = "fraction" />
<attr name =
"pivotY" format = "fraction" />
</declare-styleable>

9. enum:枚举值。
示例:
[java]

复制代码 代码如下:

<declare-styleable name="名称">

<attr name="orientation">
<enum name="horizontal" value="0"
/>
<enum name="vertical" value="1" />
</attr>

</declare-styleable>

10. flag:位或运算。
示例:
[java]

复制代码 代码如下:

<declare-styleable name="名称">

<attr name="windowSoftInputMode">
<flag name =
"stateUnspecified" value = "0" />
<flag name = "stateUnchanged" value
= "1" />
<flag name = "stateHidden" value = "2" />
<flag
name = "stateAlwaysHidden" value = "3" />
</attr>

</declare-styleable>

11.多类型。
示例:
[java]

复制代码 代码如下:

<declare-styleable name = "名称">

<attr name = "background" format = "reference|color" />

</declare-styleable>

-------------------------------------------------------------------------------------------

二、属性的使用以及自定义控件的实现
1、构思控件的组成元素,思考所需自定义的属性。
比如:我要做一个
<带阴影的按钮,按钮正下方有文字说明>(类似9宫格按钮)
新建values/attrs.xml
[java]

复制代码 代码如下:

<?xml version="1.0"
encoding="utf-8"?>
<resources>
<declare-styleable
name="custom_view">
<attr name="custom_id" format="integer" />

<attr name="src" format="reference" />
<attr name="background"
format="reference" />
<attr name="text" format="string" />

<attr name="textColor" format="color" />
<attr name="textSize"
format="dimension" />
</declare-styleable>
</resources>

以上,所定义为custom_view,custom_id为按钮id,src为按钮,background为阴影背景,text为按钮说明,textColor为字体颜色,textSize为字体大小。

2、怎么自定义控件呢,怎么使用这些属性呢?话不多说请看代码,CustomView :

复制代码 代码如下:

package com.nanlus.custom;
import
com.nanlus.custom.R;
import android.content.Context;
import
android.content.res.TypedArray;
import android.graphics.Color;
import
android.graphics.drawable.Drawable;
import android.util.AttributeSet;

import android.view.Gravity;
import android.view.View;
import
android.view.View.OnClickListener;
import android.widget.FrameLayout;

import android.widget.ImageButton;
import android.widget.ImageView;

import android.widget.TextView;
public class CustomView extends
FrameLayout implements OnClickListener {
private CustomListener
customListener = null;
private Drawable mSrc = null, mBackground = null;

private String mText = "";
private int mTextColor = 0;
private float
mTextSize = 20;
private int mCustomId = 0;
private ImageView
mBackgroundView = null;
private ImageButton mButtonView = null;
private
TextView mTextView = null;
private LayoutParams mParams = null;
public
CustomView(Context context) {
super(context);
}
public
CustomView(Context context, AttributeSet attrs) {
super(context, attrs);

TypedArray a = context.obtainStyledAttributes(attrs,

R.styleable.custom_view);
mSrc =
a.getDrawable(R.styleable.custom_view_src);
mBackground =
a.getDrawable(R.styleable.custom_view_background);
mText =
a.getString(R.styleable.custom_view_text);
mTextColor =
a.getColor(R.styleable.custom_view_textColor,
Color.WHITE);
mTextSize =
a.getDimension(R.styleable.custom_view_textSize, 20);
mCustomId =
a.getInt(R.styleable.custom_view_custom_id, 0);
mTextView = new
TextView(context);
mTextView.setTextSize(mTextSize);

mTextView.setTextColor(mTextColor);
mTextView.setText(mText);

mTextView.setGravity(Gravity.CENTER);
mTextView.setLayoutParams(new
LayoutParams(LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT));

mButtonView = new ImageButton(context);

mButtonView.setImageDrawable(mSrc);

mButtonView.setBackgroundDrawable(null);
mButtonView.setLayoutParams(new
LayoutParams(LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT));

mButtonView.setOnClickListener(this);
mBackgroundView = new
ImageView(context);
mBackgroundView.setImageDrawable(mBackground);

mBackgroundView.setLayoutParams(new LayoutParams(

LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));

addView(mBackgroundView);
addView(mButtonView);
addView(mTextView);

this.setOnClickListener(this);
a.recycle();
}
@Override

protected void onAttachedToWindow() {
super.onAttachedToWindow();

mParams = (LayoutParams) mButtonView.getLayoutParams();
if (mParams !=
null) {
mParams.gravity = Gravity.CENTER_HORIZONTAL | Gravity.TOP;

mButtonView.setLayoutParams(mParams);
}
mParams = (LayoutParams)
mBackgroundView.getLayoutParams();
if (mParams != null) {

mParams.gravity = Gravity.CENTER_HORIZONTAL | Gravity.TOP;

mBackgroundView.setLayoutParams(mParams);
}
mParams = (LayoutParams)
mTextView.getLayoutParams();
if (mParams != null) {
mParams.gravity =
Gravity.CENTER_HORIZONTAL | Gravity.BOTTOM;

mTextView.setLayoutParams(mParams);
}
}
public void
setCustomListener(CustomListener l) {
customListener = l;
}

@Override
public void onClick(View v) {
if (customListener != null)
{
customListener.onCuscomClick(v, mCustomId);
}
}
public
interface CustomListener {
void onCuscomClick(View v, int custom_id);
}

}

代码很简单,就不多说,下面来看看我们的CustomView是怎么用的,请看:
3、自定义控件的使用

话不多说,请看代码,main.xml:
[java]

复制代码 代码如下:

<?xml version="1.0"
encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:nanlus="http://schemas.android.com/apk/res/com.nanlus.custom"

android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<LinearLayout
android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_centerHorizontal="true"

android:layout_centerVertical="true"
android:orientation="horizontal"
>
<com.nanlus.custom.CustomView
android:id="@+id/custom1"

android:layout_width="wrap_content"
android:layout_height="wrap_content"

android:layout_weight="1"
nanlus:background="@drawable/background"

nanlus:custom_id="1"
nanlus:src="@drawable/style_button"

nanlus:text="按钮1" >
</com.nanlus.custom.CustomView>

</LinearLayout>
</RelativeLayout>

在这里需要解释一下,

xmlns:nanlus="http://schemas.android.com/apk/res/com.nanlus.custom"

nanlus为在xml中的前缀,com.nanlus.custom为包名
4、在Activity中,直接上代码
[java]

复制代码 代码如下:

package com.nanlus.custom;
import
android.os.Bundle;
import android.view.View;
import
android.widget.ImageButton;
import android.widget.ImageView;
import
android.widget.TextView;
import android.widget.Toast;
import
com.nanlus.BaseActivity;
import com.nanlus.custom.R;
import
com.nanlus.custom.CustomView.CustomListener;
public class CustomActivity
extends BaseActivity implements CustomListener {
@Override
protected
void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);
setContentView(R.layout.main);

((CustomView) this.findViewById(R.id.custom1)).setCustomListener(this);

}
@Override
public void onCuscomClick(View v, int custom_id) {

switch (custom_id) {
case 1:
Toast.makeText(this, "hello !!!",
Toast.LENGTH_LONG).show();
break;
default:
break;
}
}
}
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