常用的自定義控件的方式大致有三種:
1.繼承自現有控件,加以改進,如繼承TextView;
2.將幾種控件進行組合,構成新的組件;
3.繼承View類,重繪一個組件。
自定義控件的方法:
首先定義一個自定義控件類(MyView.java):
</pre><pre name="code" class="html">package com.jtext.chessdisplay;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Toast;
public class MyView extends View{
Context context1;
// TODO Auto-generated constructor stub
public MyView(Context context, AttributeSet attrs) {
super(context, attrs);
context1=context;
// TODO Auto-generated constructor stub
}
@Override
protected void onDraw(Canvas canvas){
super.onDraw(canvas);
Paint paint=new Paint();
paint.setColor(Color.RED);
paint.setShadowLayer(2, 3, 4, Color.GRAY);
Rect r=new Rect(40,40,200,100);
canvas.drawRect(r,paint);
paint.setColor(Color.BLUE);
canvas.drawText("自定義控件測試", 40, 40, paint);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
// TODO Auto-generated method stub
switch (event.getAction()){
case MotionEvent.ACTION_DOWN:
Toast.makeText(context1, "自定義組件測試",0).show();
break;
case MotionEvent.ACTION_MOVE:
Toast.makeText(context1, "HUAHUA",0).show();
break;
}
return super.onTouchEvent(event);
}
}
接着,就可以像普通控件一樣,在佈局裏聲明使用(myview.xml):
<?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="match_parent"
android:orientation="vertical"
>
<com.jtext.chessdisplay.MyView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/myView"
/>
</LinearLayout>
最後,在MainActivity裏顯示:
package com.jtext.chessdisplay;
import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
public class MainActivity extends Activity {
MyView2 mv;
MyView2 mv1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.myview);}
}
二、組合控件
以繼承佈局類來自定義控件爲例.
佈局myview2
<?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="match_parent"
android:orientation="vertical" >
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/iv"
android:layout_gravity="center_vertical"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/tv"
android:layout_gravity="center_vertical"
android:gravity="center_horizontal"/>
</LinearLayout>
控件定義MyView2.java
package com.jtext.chessdisplay;
import android.content.Context;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;
public class MyView2 extends LinearLayout{
private ImageView iv;
private TextView tv;
int i=0;
Context context1;
public MyView2(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
inflater.inflate(R.layout.myview2, this);
iv=(ImageView) findViewById(R.id.iv);
tv=(TextView)findViewById(R.id.tv);
context1=context;
iv.setOnTouchListener(new myTouchListener());
}
public void setImageResource(int resid){
iv.setImageResource(resid);
}
public void setTextView(String str,int color){
tv.setText(str);
tv.setTextColor(color);
}
class myTouchListener implements OnTouchListener {
@Override
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
switch (v.getId()){
case R.id.iv:
i++;
Toast.makeText(context1, "數量更改成功", 0).show();
tv.setText(i+"");;
break;
}
return false;
}
}
}
MainActivity裏進行顯示:
package com.jtext.chessdisplay;
import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
public class MainActivity extends Activity {
MyView2 mv;
MyView2 mv1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.myview3);
mv=(MyView2)findViewById(R.id.mv);
mv1=(MyView2)findViewById(R.id.mv1);
mv.setImageResource(R.drawable.cart);
mv.setTextView("測試", Color.RED);
mv1.setImageResource(R.drawable.cart);
mv1.setTextView("測試", Color.BLUE);
}
}