ProgressDialog 使用

全栈程序员-站长 • 2022年7月14日上午6:00 • 未分类 • 阅读 25

大家好，又见面了，我是你们的朋友全栈君。ProgressDialog

[功能]

ProgressDialog 也是一种Dialog

一般在出现ProgressDialog 后台都会再开辟Thread 来做一些耗时的工作我演示的是从100数到0 这段时间既不太长不用浪费时间等待同时也能明显地看出效果

[代码]

1. ProgressDialog 使用


public void startProgress(){
  
  
    	//to start Progress
    	pd = ProgressDialog.show(this, "loop from 100 to 0!", "is looping...", true,
    			false);
    	//pd.setIcon(R.drawable.icon);
    }

2. 开辟一个Thread来从100数到0 在数完后关闭ProgressDialog


public class TaskLoop implements Runnable {
  
  
		@Override
		public void run() {
  
  
			// TODO Auto-generated method stub
			loop(5000);

			messageListener.sendEmptyMessage(TASK_LOOP_COMPLETE);
		}

    }

public void loop(long i){
  
  
    	long j = i;
    	while(j>0){
  
  
    		Log.d("tag",j+"");

    		j = j-1;
		}

    }

3. 运行该Thread


Thread loop = new Thread(new TaskLoop());
loop.start();

4.定义一个Handler 用于接受关闭ProgressDialog 的通知


private Handler messageListener = new Handler(){
  
  
    	public void handleMessage(Message msg) {
  
  
			switch(msg.arg1){
  
  
			case TASK_LOOP_COMPLETE:
				pd.dismiss();
				break;

			}
		}
    };

[所有代码]


public class MyProgressUsage extends Activity {
  
  
	public final static int TASK_LOOP_COMPLETE = 0;

	ProgressDialog pd;

	TextView tv;
	/** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
  
  
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        findViewById(R.id.start).setOnClickListener(new OnClickListener(){
  
  
			public void onClick(View v) {
  
  
				// TODO Auto-generated method stub
				startLoop();
			}
        });
    }

    public void startLoop(){
  
  

    	startProgress();

    	Thread loop = new Thread(new TaskLoop());
    	loop.start();
    }


    public class TaskLoop implements Runnable {
  
  
		@Override
		public void run() {
  
  
			// TODO Auto-generated method stub
			loop(5000);

			messageListener.sendEmptyMessage(TASK_LOOP_COMPLETE);
		}

    }

    public void startProgress(){
  
  
    	//to start Progress
    	pd = ProgressDialog.show(this, "loop from 100 to 0!", "is looping...", true,
    			false);
    	//pd.setIcon(R.drawable.icon);
    }

    //to do some time-cost task
    public void loop(long i){
  
  
    	long j = i;
    	while(j>0){
  
  
    		Log.d("tag",j+"");

    		j = j-1;
		}

    }

    private Handler messageListener = new Handler(){
  
  
    	public void handleMessage(Message msg) {
  
  
			switch(msg.arg1){
  
  
			case TASK_LOOP_COMPLETE:
				pd.dismiss();
				break;

			}
		}
    };

}