android 对话框进度条使用

最新推荐文章于 2023-07-16 20:29:02 发布

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本文详细介绍了如何在Android应用中使用ProgressDialog来展示进度条对话框。通过具体的代码实例，展示了ProgressDialog的创建、配置及如何通过Handler更新进度条的状态。

ProgressDialog和普通的不太一样，它的创建依赖于activity的几个类。可以看下面资料：

http://android.blog.51cto.com/268543/333769

http://blog.youkuaiyun.com/jamesliulyc/article/details/6375598

下来的例子来自于 http://blog.youkuaiyun.com/jamesliulyc/article/details/6375598 的修改。

布局

<?xml version="1.0" encoding="utf-8"?>  
<LinearLayout  
  xmlns:android="http://schemas.android.com/apk/res/android"  
  android:layout_width="fill_parent"  
  android:layout_height="wrap_content">  
  <Button android:id="@+id/button"  
    android:text="显示进度条对话框"  
    android:layout_width="fill_parent"  
    android:layout_height="wrap_content"/>  
</LinearLayout>

activity的代码

package endual.progressdialog.activity;

import android.app.Activity;
import android.app.Dialog;
import android.app.ProgressDialog;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.Button;

public class MainActivity extends Activity {
	
	private final int PROGRESS_DIALOG = 1;
	
	private final int INCREASE = 0;
	
	private ProgressDialog progressDialog = null;
	
	private Handler handler = null;
	
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        Button button = (Button) findViewById(R.id.button);
        View.OnClickListener listener = 
        	new View.OnClickListener() {
				
				@Override
				public void onClick(View view) {
					showDialog(PROGRESS_DIALOG);
				}
			};
		button.setOnClickListener(listener);
		
		handler = new Handler() {
			@Override
			public void handleMessage(Message msg) {
				switch(msg.what) {
					case INCREASE:
						progressDialog.incrementProgressBy(1);
						if(progressDialog.getProgress() >= 100) {
						//	progressDialog.dismiss();
						}
						break;
					case 2 :
						progressDialog.dismiss() ;
						break;
				}
				super.handleMessage(msg);
			}
		};
    }
    
    @Override
    public Dialog onCreateDialog(int id) {
    	switch(id) {
	    	case PROGRESS_DIALOG:	
				//this表示该对话框是针对当前Activity的
				progressDialog = new ProgressDialog(this);
				//设置最大值为100
				progressDialog.setMax(100);
				//设置进度条风格STYLE_HORIZONTAL
				progressDialog.setProgressStyle(
						ProgressDialog.STYLE_HORIZONTAL);
				progressDialog.setTitle("进度条对话框");
	    		break;
    	}
    	return progressDialog;
    }
    
	@Override
    public void onPrepareDialog(int id, Dialog dialog) {
    	
    	switch(id) {
	    	case PROGRESS_DIALOG:
	    		//将进度条清0
	    		progressDialog.incrementProgressBy(-progressDialog.getProgress());
	    		new Thread() {
		    		public void run() {
		    			for(int i=0; i<=100; i++) {
		    							
		    				handler.sendEmptyMessage(INCREASE);
							if(progressDialog.getProgress() >= 100) {
								handler.sendEmptyMessage(2); //发送消失的信号
								break;
							}
							try {
								Thread.sleep(50);
							} catch (InterruptedException e) {
								e.printStackTrace();
							}
			    		}
		    		}
	    		}.start();
	    		break;
    	}
    }
}

点击按钮出现对话框的进度条，只有当进度条完成以后，才能进行相应的操作