Question

我是Android应用程序开发的新手，试图学习自定义视图开发。下面是我创建了一个按钮的简单布局，点击该按钮将启动游戏活动。游戏活动具有自定义布局。我的问题是，点击按钮后，它会启动新活动，但不会显示任何内容。它加载了空布局。我希望android在点击按钮时加载一个圆圈。

MainActivity.java

package com.shashi.customview2;


import android.app.Activity;

import android.content.Intent;

import android.os.Bundle;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.view.View.OnClickListener;


public class MainActivity extends Activity implements OnClickListener
{

@Override
protected void onCreate(Bundle savedInstanceState) 
{

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    View gamebutton=(View) findViewById(R.id.hi);
    gamebutton.setOnClickListener(this);
}

public void onClick(View v)
{
    Intent intent =new Intent(this,Game.class);
    startActivity(intent);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}
}

game.java

package com.shashi.customview2;

import android.app.Activity;

import android.os.Bundle;

public class Game extends Activity 
{

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{

    super.onCreate(savedInstanceState);

    setContentView(R.layout.custlayout);

}

}

自定义视图类：

package com.shashi.customview2;

import android.content.Context;

import android.content.res.TypedArray;

import android.graphics.Canvas;

import android.graphics.Paint;

import android.graphics.Paint.Style;

import android.util.AttributeSet;

import android.view.View;

public class custview extends View 
{

    private int circleCol;
    private Paint circlePaint;



    public custview(Context context ,AttributeSet attrs)
    {
        super(context,attrs);
        circlePaint = new Paint();
        TypedArray a = context.getTheme().obtainStyledAttributes(attrs,
                R.styleable.custview, 0, 0);
        try {
            //get the text and colors specified using the names in attrs.xml
             circleCol = a.getInteger(R.styleable.custview_circleColor, 0);
              } 
        finally 
        {
            a.recycle();
        }

        // TODO Auto-generated method stub
    }

protected void OnDraw(Canvas canvas)
{

int viewWidthHalf = this.getMeasuredWidth()/2;
int viewHeightHalf = this.getMeasuredHeight()/2;
int radius = 0;

if(viewWidthHalf>viewHeightHalf)

    radius=viewHeightHalf-10;

else
    radius=viewWidthHalf-10;


circlePaint.setStyle(Style.FILL);
circlePaint.setAntiAlias(true);

circlePaint.setColor(circleCol);

canvas.drawCircle(viewWidthHalf, viewHeightHalf, radius, circlePaint);

}

}

自定义布局：

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:custom="http://schemas.android.com/apk/res/com.shashi.customview2"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:orientation="vertical" >

<com.shashi.customview2.custview
    android:id="@+id/custView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_margin="5dp"
    custom:circleColor="#ff0099"/>
</LinearLayout>

自定义视图未加载

0 个答案: