android用户界面组件Widget进度条ProgressBar

android的进度条有对话框进度条、标题进度条和水平进度条

一、对话框进度条

创建步骤

1、覆盖Activity的onCreateDialog()方法，并在其中创建对话框。

2、调用Activity的showDialog()方法，显示进度条对话框。

/Chapter04_UI_ProgressBar01/src/com/amaker/test/MainActivity.java

package com.amaker.test;

import android.app.Activity;
import android.app.Dialog;
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {
    private Button myBtn;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        myBtn = (Button)findViewById(R.id.Button01);
        myBtn.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                showDialog(0);
            }
        });
    }

    @Override
    protected Dialog onCreateDialog(int id) {
        ProgressDialog dialog = new ProgressDialog(this);
        // 可以不显示标题
        dialog.setTitle("测试对话框");
        dialog.setIndeterminate(true);
        dialog.setMessage("程序正在加载请稍后！");
        dialog.setCancelable(true);
        
        dialog.setButton(Dialog.BUTTON_POSITIVE, "确定", 
                new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.cancel();
                    }
                }
        );
        
        return dialog;
    }
}

二、标题栏进度条

1、调用Activity的requestWindowFeatures()方法，获得进度条。

2、调用Activity的setProgressBarIndeterminateVisibility()方法，显示进度条对话框。

/Chapter04_UI_ProgressBar02/src/com/amaker/test/MainActivity.java

package com.amaker.test;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {
    /** Called when the activity is first created. */
    
    private Button b1,b2;
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        
       requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
       setContentView(R.layout.main);
       b1 = (Button)findViewById(R.id.Button01);
       b2 = (Button)findViewById(R.id.Button02);
       
       b1.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            setProgressBarIndeterminateVisibility(true);
        }
       });
       
       b2.setOnClickListener(new OnClickListener() {
           public void onClick(View v) {
               setProgressBarIndeterminateVisibility(false);
           }
       });
    }
}

三、水平进度条

创建步骤

1、在布局文件中声明ProgressBar。

2、在Activity中获得ProgressBar实例。

3、调用ProgressBar的incrementProgressBy()方法增加和减少进度。

/Chapter04_UI_ProgressBar03/src/com/amaker/test/MainActivity.java

package com.amaker.test;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ProgressBar;

public class MainActivity extends Activity {
    private Button b1,b2;
    ProgressBar progressBar;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        b1 = (Button)findViewById(R.id.Button01);
        b2 = (Button)findViewById(R.id.Button02);
        progressBar = (ProgressBar)findViewById(R.id.ProgressBar01);
        
        b1.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                    progressBar.incrementProgressBy(1);
            }
        });
        
        b2.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                progressBar.incrementProgressBy(-1);
            }
        });
        
    }
}

 /Chapter04_UI_ProgressBar03/res/layout/main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<ProgressBar 
    android:id="@+id/ProgressBar01" 
    style="?android:attr/progressBarStyleHorizontal"
    android:layout_width="200dip"
    android:layout_height="wrap_content"
    android:max="100"
    android:progress="50"
></ProgressBar>

<Button 
android:id="@+id/Button01" 
android:layout_width="wrap_content" 
android:layout_height="wrap_content" 
android:text="增加"></Button>

<Button 
android:id="@+id/Button02" 
android:layout_width="wrap_content" 
android:layout_height="wrap_content" 
android:text="減少"></Button>

</LinearLayout>